Youre right; the definition in your book is simplistic. A terminal alkyne would be better defined as an alkyne with the formula $\ce{RC_2H}$, differentiating from an internal alkyne, which would have the formula $\ce{RC_2R}$ and the added stipulation that neither R nor R can be a hydrogen. Equivalently stated as in Wikipedia, an internal alkyne has carbon substitutents on all acetylenic carbons, and a terminal alkyne is therefore not an internal alkyne because at least one acetylenic carbon has a hydrogen bonded to it.. The example formula you cite is vinylacetylene, systematic name butenyne or 1-buten-3-yne (heres your IUPAC nomenclature rules favoring double bonds at work; otherwise itd be ethynylbutene or similar). It is indeed an example of a terminal alkyne, having the exploded formula (C2H3)C2H.. ...
Evaluation of biofilm formation on novel copper-catalyzed azide-alkyne cycloaddition (CuAAC)-based resins for dental restoratives Journal Article ...
TY - JOUR. T1 - Hydrosilylation of alkynes catalysed by platinum on titania. AU - Alonso, Francisco. AU - Buitrago, Robison. AU - Moglie, Yanina. AU - Ruiz-Martínez, Javier. AU - Sepúlveda-Escribano, Antonio. AU - Yus, Miguel. N1 - Generated from Scopus record by KAUST IRTS on 2019-08-08. PY - 2011/1/1. Y1 - 2011/1/1. N2 - The heterogeneous hydrosilylation of alkynes catalysed by platinum on titania is reported. A variety of hydrosilanes react with both terminal and internal alkynes to furnish the corresponding vinyl silanes in high yields and short reaction times as well as in a regio- and stereoselective manner. The catalyst can be easily recovered and reused in several consecutive cycles. © 2010 Elsevier B.V. All rights reserved.. AB - The heterogeneous hydrosilylation of alkynes catalysed by platinum on titania is reported. A variety of hydrosilanes react with both terminal and internal alkynes to furnish the corresponding vinyl silanes in high yields and short reaction times as well as ...
TY - JOUR. T1 - Rhodium-catalyzed oxidative cycloaddition of benzamides and alkynes via C-H/N-H activation. AU - Hyster, Todd K.. AU - Rovis, Tomislav. PY - 2010/8/4. Y1 - 2010/8/4. N2 - The oxidative cycloaddition of benzamides and alkynes has been developed. The reaction utilizes Rh(III) catalysts in the presence of Cu(II) oxidants, and is proposed to proceed by N-H metalation of the amide followed by ortho C-H activation. The resultant rhodacycle undergoes alkyne insertion to form isoquinolones in good yield. The reaction is tolerant of extensive substitution on the amide, alkyne, and arene, including halides, silyl ethers, and unprotected aldehydes as substituents. Unsymmetrical alkynes proceed with excellent regioselectivity, and heteroaryl carboxamides are tolerated leading to intriguing scaffolds for medicinal chemistry. A series of competition experiments shed further light on the mechanism of the transformation and reasons for selectivity.. AB - The oxidative cycloaddition of benzamides ...
Rh(III)-catalyzed C−H bond annulation with alkynes has excogitated into a potent method for the preparation of highly substituted polycyclic aromatic and heteroaromatic compounds. Here Rh(III)-catalyzed annulation of 4-phenyl quinazolines with internal alkynes via dual C−H bond activation has been explored. The synthetic procedure has the advantages of high efficiency and functional group tolerance, excellent regioselectivity and broad substrate scope under mild conditions and some of the resulting products exhibit intense fluorescence in the solution state. Such structural motifs may important precursors for further transformations into biologically active compounds & π-conjugated functional materials such as organic semiconductors and luminescent materials which have broad prospect in future life.. ...
Transition-metal-mediated cross coupling reaction of alkynes and alkenes has recently gained increasing significance in organic chemistry because it represents an efficient method for the formation of new carbon-carbon bond. In recent years, two types of the coupling reactions have been developed: intramolecular couplings of enynes and intermolecular couplings of alkynes and alkenes. These results were classified into two mechanistic pathways, one not involving carbon-carbon bond cleavage, insertion mechanism, and the other involving carbon-carbon bond cleavage, metathesis mechanism. While the coupling reactions of alkynes with substituted alkenes have been well developed, there are very few reports on the coupling of alkynes with the simplest alkene, ethylene documented in the literature. Our research goal is to develop a new rutheniumbased system to study the coupling reactions of alkynes with ethylene, and extend its scope to enyne and substituted alkenes.
TY - JOUR. T1 - Well-defined (co)polypeptides bearing pendant alkyne groups. AU - Zhao, Wei. AU - Gnanou, Yves. AU - Hadjichristidis, Nikos. N1 - KAUST Repository Item: Exported on 2020-10-01 Acknowledgements: The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST).. PY - 2016. Y1 - 2016. N2 - A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.. AB - A novel metal-free strategy, using hydrogen-bonding ...
Wang, Y.-F., Toh, K. K., Lee, J.-Y. and Chiba, S. (2011), Synthesis of Isoquinolines from α-Aryl Vinyl Azides and Internal Alkynes by Rh-Cu Bimetallic Cooperation. Angew. Chem., 123: 6049-6053. doi: 10.1002/ange.201101009 ...
Synonyms for alkyne in Free Thesaurus. Antonyms for alkyne. 2 synonyms for alkyne: acetylene, ethyne. What are synonyms for alkyne?
Communications DOI: 10.1002/anie.201100252 Asymmetric Catalysis C1-Symmetric Rh/Phebox-Catalyzed Asymmetric Alkynylation of a-Ketoesters** Takashi Ohshima,* Takahito Kawabata, Yosuke Takeuchi, Takahiro Kakinuma, Takanori Iwasaki, Takayuki Yonezawa, Hajime Murakami, Hisao Nishiyama, and Kazushi Mashima* Catalytic asymmetric alkynylation of carbonyl compounds is one of the most efficient routes for the synthesis of optically active propargylic alcohols, which are useful and versatile building blocks for a variety of functionalized molecules, such as biologically active natural products.[1] In the initial stages of development of this transformation, stoichiometric amounts of metal reagents such as organolithium, organomagnesium, and diorganozinc compounds were used to increase the nucleophilicity of the alkyne and to prevent an undesired retro reaction.[1, 2] In terms of atom economy,[3] however, the direct in situ generation of a metal alkynylide species from terminal alkynes using a catalytic ...
A regioselective hydroboration of alkynes has been developed by using commercially available zinc triflate as a catalyst, in the presence of catalytic amount of NaBHEt3. The reaction tolerates a wide range of terminal alkynes having several synthetically useful functional groups and proceeds regioselectively to furnish hydroborated products in moderate to excellent yields. This system shows moderate chemoselectivity towards terminal C equivalent to C bond over terminal and internal C=C bond and internal C equivalent to C bond.. ...
In this work, we confirmed that the copper-catalysed azide-alkyne cycloaddition (CuAAC) reaction is an effective method for the organic-functionalization of polyoxometalates (POMs). Herein, for the first time, four novel 1,2,3-triazole functionalized polyoxovanadate (POV) organic-inorganic hybrids, (Bu4N)2[V6O13{(O
TY - GEN. T1 - A new sinthetic application of (dichloroiodo)benzene in reactions with alkenes and alkynes. AU - Yusubova, R. J.. AU - Filimonov, V. D.. AU - Yusubov, M. S.. AU - Chi, Ki Whan. PY - 2004. Y1 - 2004. N2 - A convenient synthesis of vicinal methoxychlorides, methoxyiodides from alkenes and alkynes using PhICl2/CH3OH, I 2/PhICl2/CH3OH is described.. AB - A convenient synthesis of vicinal methoxychlorides, methoxyiodides from alkenes and alkynes using PhICl2/CH3OH, I 2/PhICl2/CH3OH is described.. KW - (dichloroiodo)Benzene. KW - Alkenes. KW - Alkynes. KW - Chloromethoxylation. KW - Iodomethoxylation. UR - http://www.scopus.com/inward/record.url?scp=29144459782&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=29144459782&partnerID=8YFLogxK. M3 - Conference contribution. AN - SCOPUS:29144459782. SN - 0780383834. SN - 9780780383838. VL - 2. SP - 97. EP - 98. BT - 8th Korea-Russia International Symposium on Science and Technology - Proceedings: KORUS 2004. ER - ...
TY - JOUR. T1 - New oxidative transformations of alkenes and alkynes under the action of diacetoxyiodobenzene. AU - Yusubov, M. S.. AU - Zholobova, G. A.. AU - Filimonova, I. L.. AU - Chi, Ki Whan. PY - 2004/8/1. Y1 - 2004/8/1. N2 - Treatment of alkenes and alkynes with diacetoxyiodobenzene activated by mineral and organic acids predominantly results in oxidative rearrangement. 1,4-Diphenylbutadiene in MeOH gives 3,4-dimethoxy-1,4-diphenylbut-1-ene.. AB - Treatment of alkenes and alkynes with diacetoxyiodobenzene activated by mineral and organic acids predominantly results in oxidative rearrangement. 1,4-Diphenylbutadiene in MeOH gives 3,4-dimethoxy-1,4-diphenylbut-1-ene.. KW - Alkenes. KW - Alkynes. KW - Diacetoxyiodobenzene. KW - Oxidative rearrangement. KW - Polyvalent iodine compounds. UR - http://www.scopus.com/inward/record.url?scp=14944340734&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=14944340734&partnerID=8YFLogxK. U2 - 10.1007/s11172-005-0027-8. DO - ...
Best Chemical Properties Of The Alkynes Online Homework Help, Assignment Help providers on internet. 24 X 7 live online tutoring at Assignmenthelp.net.
TY - JOUR. T1 - Synthesis of Strained 1,3-Diene Macrocycles via Copper-Mediated Castro-Stephens Coupling/Alkyne Reduction Tandem Reactions. AU - Li, Wei. AU - Schneider, Christopher M.. AU - Georg, Gunda I.. PY - 2015/8/7. Y1 - 2015/8/7. N2 - A copper-mediated macrocyclization involving the reaction of a vinyl iodide and a terminal alkyne followed by an in situ reduction of the enyne intermediate is reported. The reaction generates a conjugated Z-double bond within a strained medium-size lactone, lactam, or ether macrocycle. A variety of macrocyclic compounds bearing different ring sizes and functionalities were synthesized. A complementary stepwise procedure was also developed for less strained ring systems.. AB - A copper-mediated macrocyclization involving the reaction of a vinyl iodide and a terminal alkyne followed by an in situ reduction of the enyne intermediate is reported. The reaction generates a conjugated Z-double bond within a strained medium-size lactone, lactam, or ether ...
Highly enantioselective allylic alkynylation of racemic bromides under biphasic condition is furnished in this report. This approach employs functionalized terminal alkynes as pro-nucleophiles and provides 6- and 7-membered cyclic 1,4-enynes with high yields and excellent enantioselectivities (up to 96% ee) under mild conditions. Enantioretentive derivatizations highlight the synthetic utility of this transformation. Cold-spray ionization mass spectrometry (CSI-MS) and X-ray crystallography were used to identify some catalytic intermediates, which include guanidinium cuprate ion pairs and a copper-alkynide complex. A linear correlation between the enantiopurity of the catalyst and reaction product indicates the presence of a copper complex bearing a single guanidine ligand at the enantio-determining step. Further experimental and computational studies supported that the alkynylation of allylic bromide underwent an anti-SN2 pathway catalyzed by nucleophilic cuprate species. Moreover, ...
TY - JOUR. T1 - Bismuth(III)-Catalyzed hydration of terminal alkynes. T2 - Sustainable synthesis of methyl ketones in batch and flow. AU - Ötvös, Sándor B.. AU - Szécsényi, Zsanett. AU - Fülöp, F.. PY - 2019/8/5. Y1 - 2019/8/5. N2 - Environmentally benign synthesis of methyl ketones is demonstrated via unprecedented bismuth(III)-catalyzed activation and Markovnikov-type hydration of terminal acetylenes. Besides a batch process operating under reasonably mild conditions, a chemically intensified high-temperature continuous-flow methodology has also been developed using a coil reactor. The preparative capabilities of the flow process were demonstrated with multigram-scale alkyne hydrations. The methods presented rely on readily available bismuth(III) salts as green catalysts and exhibit less environmental concerns than earlier methods.. AB - Environmentally benign synthesis of methyl ketones is demonstrated via unprecedented bismuth(III)-catalyzed activation and Markovnikov-type hydration ...
Acetylene is the ultimate carbon building block (on paper, anyway!). It bears two relatively acidic C-H bonds (pKa 25) and can therefore be alkylated (i.e. deprotonated to give its conjugate base, then treated with an alkyl halide) on either end giving either a mono-substituted (also known as a terminal alkyne) or di-substituted (internal) alkyne as desired. This is important because in first semester organic chemistry, this reaction represents an important means of extending the carbon chain. You dont learn that many reactions that form C-C. This reaction comes up a lot ...
Outline1. Bonding in alkynes. sp-Hybridization2. Physical properties and nomenclature of alkynes 3. Preparation and use of alkynes4. Addition to triple bonds. Hydrohalogenation5. Addition to triple bonds. Hydration6. Addition to triple bonds. Hydroboration-oxidation7. Addition to triple bonds....
Alkynes Hydrocarbons that contain carbon-carbon triple bonds C≡C Acetylene, the simplest alkyne is produced industrially from methane and steam at high temperature Our study of alkynes provides an introduction to organic synthesis, the preparation of organic molecules from simpler organic molecules
TY - JOUR. T1 - Hydrofluoroarylation of alkynes with fluoroarenes. AU - Kanyiva, Stephen Kyalo. AU - Kashihara, Natsuko. AU - Nakao, Yoshiaki. AU - Hiyama, Tamejiro. AU - Ohashi, Masato. AU - Ogoshi, Sensuke. PY - 2010/11/21. Y1 - 2010/11/21. N2 - A combination of Ni(cod)2 and PCyp3 is found to be an effective catalyst for chemoselective activation of the C-H bond of fluoroarenes over C-F bonds followed by insertion of alkynes to allow direct alkenylation of the electron-deficient arenes. The characteristics of the reactions are: a C-H bond ortho to a fluorine substituent is selectively activated; the reactivity of fluorobenzenes is roughly proportional to the number of fluorine atoms. The reaction conditions tolerate a broad range of both alkynes and fluoroarenes containing both electron-withdrawing and -donating groups, thus allowing efficient synthesis of a variety of substituted ethenes containing a fluoroaryl motif in high regio- and stereoselective manners. Mechanistic studies including ...
TY - JOUR. T1 - A strategy for conditional orthogonal sequential CuAAC reactions using a protected aromatic ynamine. AU - Hatit, Marine Z. C.. AU - Seath, Ciaran P.. AU - Watson, Allan J. B.. AU - Burley, Glenn A.. N1 - This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Organic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.joc.7b00545.. PY - 2017/4/28. Y1 - 2017/4/28. N2 - A method for conditional control of orthogonal sequential Cu-catalyzed azide alkyne cycloaddition (CuAAC) reactions is reported. The inherent reactivity of an aromatic ynamine is controlled by a silyl protecting group that allows the selective CuAAC reaction of less reactive alkynes. Alternatively, the same protected ynamine undergoes selective CuAAC reaction via silyl deprotection in situ to give theynamine click products. This ...
This has some implications in the properties and chemical reactivity of sigma and pi bonds. Ethyne or acetylene, HC=CH, is the simplest alkyne example. The process for understanding the sp hybridization process for carbon is basically an extension of the other two types (sp 3 and sp 2). Thus, in acetylene (ethyne), there are two unhybridized orbitals, which, by convention are and (see figure below): Figure: Illustrating the sp orbitals. The triple bonded carbon atoms of acetylene aresp hybridized. The sigma bond is short and strong. E)An alkyne reacts as an electrophile,and is therefore electron poor. Type of â ¦ You should try to work out this scheme on your own and see if your predictions agree with those presented in the textbook. is related to Unsaturated Hydrocarbons Quiz. The Structure of Ethyne (Acetylene): sp Hybridization ** Hydrocarbons in which two carbon atoms share three pairs of electrons between them, and are thus bonded by a triple bond, are called alkynes. Correspondingly, ...
Herein we report unprecedented manganese-catalyzed semihydrogenation of internal alkynes to (Z)-alkenes using ammonia borane as a hydrogen donor. The reaction is catalyzed by a pincer complex of the earth-abundant manganese(II) salt in the absence of any additives, base, or superhydride. The ammonia borane smoothly reduces the manganese precatalyst [Mn(II)-PNP][Cl]2 to the catalytically active species [Mn(I)-PNP]-hydride in the triplet spin state. This manganese hydride is highly stabilized by complexation with the alkyne substrate. Computational density functional theory (DFT) analysis studies of the reaction mechanism rationalize the origin of stereoselectivity toward formation of (Z)-alkenes ...
Alkyne functionalized Single layer graphene Flake size: 0.5-5 microns. Thickness: Single atomic layer >80% Purity: Carbon contents over 80% Alkyne functionalized online from Mknano.com.
Alkynes and Their Reactions Naming Alkynes Alkynes are named in the same general way that alkenes are named. In the IUPAC system, change the ane ending of the parent alkane name to the suffix yne. Choose
ALKYnes sem 1: 2011/2012. Khadijah Hanim bt Abdul Rahman School of Bioprocess Engineering, UniMAP Week 5: 13/10/2011 [email protected] Learning outcomes. Structure, nomenclature and naming alkynes DEFINE and ILLUSTRATE the principle in naming alkynes on few examples...
A Lewis acid-catalyzed insertion of unsymmetrical alkynes into electron-deficient alkenes was developed for the first time, and used to produce 34 hitherto unreported pentacyclic benzo[5,6]chromeno[2,3-b]indoles with generally good yields and complete stereoselectivity. A Yb(OTf)3-catalyzed reaction between
Preparation, properties and reactions of alkenes and alkynes: Physical properties of alkenes and alkynes (boiling points, density and dipole moments); Acidity of alkynes; Acid catalysed hydration of alkenes and alkynes (excluding the stereochemistry of addition and elimination); Reactions of alkenes with KMnO4 and ozone; Reduction of alkenes and alkynes; Preparation of alkenes and alkynes by elimination reactions; Electrophilic addition reactions of alkenes with X2, HX, HOX and H2O (X=halogen); Addition reactions of alkynes; Metal acetylides ...
Rhodium-Catalyzed Intermolecular Alkyne Cyclotrimerization Route to a Functionalized CycloparaphenyleneRhodium-Catalyzed Intermolecular Alkyne Cyclotrimerization Route to a Functionalized Cycloparaphenylene ...
A metal-free oxidative trifluoromethyl-thiolation of terminal alkynes using readily available CF3SiMe3 and elemental sulfur at room temperature has been developed. This reaction provides an efficient and convenient method for the preparation of alkynyl trifluoromethyl sulfides bearing a wide range of functional groups. Preliminary investigation revealed that elemental sulfur instead of air acted as the oxidant ...
TY - JOUR. T1 - Dual Inhibition of Mycobacterial Fatty Acid Biosynthesis and Degradation by 2-Alkynoic Acids. AU - Morbidoni, Hector R.. AU - Vilchèze, Catherine. AU - Kremer, Laurent. AU - Bittman, Robert. AU - Sacchettini, James C.. AU - Jacobs, William R.. N1 - Funding Information: H.R.M. is a Career Investigator of Consejo de Investigaciones de la Universidad Nacional de Rosario (CIURN), Argentina. This work was supported by National Institutes of Health grant AI43268. L.K. is supported by a grant from the Centre National de la Recherche Scientifique (Actions Thématiques et Incitatives sur Programmes Microbiologie Fondamentale).. PY - 2006/3. Y1 - 2006/3. N2 - 2-Hexadecynoic acid and 2-octadecynoic acid have cidal activity against Mycobacterium smegmatis and Mycobacterium bovis BCG. At subinhibitory concentrations, M. smegmatis rapidly transformed [1-14C]-2-hexadecynoic acid into endogenous fatty acids and elongated them into mycolic acids. Toxic concentrations of 2-hexadecynoic acid ...
TY - JOUR. T1 - Catalytic Enantioselective Addition of Terminal Alkynes to Aldehydes: Preparation of (S)-(-)-1,3-Diphenyl-2-Propyn-1-ol and (S)-(-)-4-Methyl-1-Phenyl-2-Pentyn-1,4-Diol. AU - Takita, Ryo. AU - Harada, Shinji. AU - Ohshima, Takashi. AU - Matsunaga, Shigeki. AU - Shibasaki, Masakatsu. PY - 2008. Y1 - 2008. U2 - 10.1002/0471264229.os085.13. DO - 10.1002/0471264229.os085.13. M3 - Article. VL - 85. JO - Organic Syntheses. JF - Organic Syntheses. SN - 0078-6209. ER - ...
ABSTRACT FOR PART I: HYDROPHENOXYLATION REACTIONS CATALYZED BY ARYLGOLD(I) COMPOUNDS Both carbine and phosphine ligated arylgold(I) compounds have been synthesized and investigated as single-component catalysts for the hydrophenoxylation of unactivated internal alkynes to yield vinyl ethers. Catalysts containing either JohnPhos or IPr/SIPr were found to be the most efficient catalysts during the screening process. Electron-withdrawing and electron-donating groups on the phenols were tolerated using these catalysts. No silver salts, acids, or solvents were needed for the catalysis, and either microwave or conventional heating afforded moderate to excellent yields of the vinyl ethers. ABSTRACT FOR PART II: ARYLGOLD(I) COMPOUNDS TO PROMOTE THE ADDITION OF DIPHENYLPHOSPHINIC ACID TO TERMINAL ALKYNES Arylgold compounds were investigated as single component catalysts for the addition of diphenylphosphinic acid to terminal alkynes using a microwave reactor. Both carbene and phosphine ligated compounds were
A mild strategy for highly regioselective hydration of the alkynes (internal and terminal) has been developed employing intramolecular ketone as the directing group under Ag(I) catalysis. were using acid to catalyze this transition. For terminal alkynes the addition of water follows the Markovnikov rule, as in the second example below, and the final product ia a methyl ketone ( except for acetylene, shown in the first example ). And then we have H2O and H2SO4 are If youre seeing this message, it means were having trouble loading external resources on our website. So this is my enol form. see a very similar reaction where we do a base-catalyzed mechanism for this arrangement in a few minutes here. Now the equilibrium is actually In contrast, the indirect hydration by the reaction sequence of hydroboration, oxidation and hydrolysis results in the anti-Markovnikov product. acid-catalyzed tautomerization. The first step is an acid/base reaction where the π electrons of the triple bond acts as a ...
Ligand lability offers a unique opportunity for access to metal-ligand cooperativity (MLC), helping to direct new organometallic and catalytic reactions. In recent years, ligand-assisted C-H bond activation and, more generally, proton migration have been of particular interest. This paper describes a detailed computational study into the mechanism, as well as the region and stereoselectivity, observed in a recently reported transformation where MLC in a 16-electron iridium(III) phosphoramidate complex plays a critical role in directing the activation of terminal alkynes toward the generation of novel five-membered (E)-vinyloxyirida(III)cycles. Five possible pathways for the formation of such products were investigated. Based on our findings, it is proposed that the reaction proceeds via a ligand-assisted proton shuttle (LAPS) mechanism, where the phosphoramidate phosphoryl (P=O) group assists in both alkyne C-H bond activation and C-H bond formation to form a vinylidene intermediate. Next, C-O ...
Poly(ethylene glycol) (PEG) is one of the most extensively studied antifouling coatings due to its ability to reduce protein adsorption and improve biocompatibility. Although the use of PEG for antifouling coatings is well established, the stability and density of PEG layers are often inadequate to provide optimum antifouling properties. To improve on these shortcomings, we employed the stepwise construction of PEG layers onto a silicon surface. Acetylene-terminated alkyl monolayers were attached to nonoxidized crystalline silicon surfaces via a one-step hydrosilylation procedure with 1,8-nonadiyne. The acetylene-terminated surfaces were functionalized via a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction of the surface-bound alkynes with an azide to produce an amine terminated layer. The amine terminated layer was then further conjugated with PEG to produce an antifouling surface. The antifouling surface properties were investigated by testing adsorption of human serum albumin ...
In systematic chemical nomenclature, alkynes are named with the Greek prefix system without any additional letters. Examples include ethyne or octyne. In parent chains with four or more carbons, it is necessary to say where the triple bond is located. For octyne, one can either write 3-octyne or oct-3-yne when the bond starts at the third carbon. The lowest number possible is given to the triple bond. When no superior functional groups are present, the parent chain must include the triple bond even if it is not the longest possible carbon chain in the molecule. Ethyne is commonly called by its trivial name acetylene.. In chemistry, the suffix -yne is used to denote the presence of a triple bond. In organic chemistry, the suffix often follows IUPAC nomenclature. However, inorganic compounds featuring unsaturation in the form of triple bonds may be denoted by substitutive nomenclature with the same methods used with alkynes (i.e. the name of the corresponding saturated compound is modified by ...
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Jie Zhou,Jingjing Shi,Qi ZS,et al. Mild and Efficient Ir(III)-Catalyzed Direct C−H Alkynylation of N‑Phenoxyacetamides with Terminal Alkyne[J]. ACS Catalysis,2016,6(0):6999 ...
Various non-fluorescent alkynes for copper-catalyzed Click Chemistry. Fluorescent dye alkynes are listed under Reactive dyes category.
As you should know already, carbon is generally found in a tetravalent state - it forms four covalent bonds with other atoms. As you know from the section on alkenes, all four bonds are not necessarily to different atoms, because carbon atoms can double-bond to one another. What this does is create the appearance of only being bound to three other atoms, but in actuality four bonds exist. Alkenes are molecules that consist of carbon and hydrogen atoms where one or more pairs of carbon atoms participate in a double bond, which consists of one sigma (σ) and one pi (π) bond. Alkynes are also molecules consisting of carbon and hydrogen atoms, but instead of forming a double bond with only one sigma (σ) and one pi (π) bond, the alkyne has at least one pair of carbon atoms who have a σ and two π bonds -- a triple bond. The carbon-carbon triple bond, then, is a bond in which the carbon atoms share an s and two p orbitals to form just one σ and two π bonds between them. This results in a linear ...
Role of small molecules such as drugs or metabolites in cells is commonly studied by fluorescence microscopy in which a fluorescent label is attached to the molecule. However, fluorescent labels are typically large that often interfere with the normal cellular function of the molecule. To avoid the use of bulky fluorescent labels, we introduce a technique that uses a simple small chemical tag called alkyne consisting of two carbons connected by a triple bond. The alkyne-tagged molecule is imaged using Raman microscopy that detects the strong Raman signal from the CC triple bond stretching vibration (~2120 cm-1). Because the alkyne signal is located in the silent region of the cell (1800-2700 cm-1), it does not interfere with any intrinsic cellular Raman signals. Here, we demonstrate this technique by showing Raman images of an alkyne-tagged component of DNA in a living cell using a slit-scanning confocal Raman microscope. This fast imaging technique is based on a line-shaped focus illumination ...
Carbon-carbon double bonds are pretty common in nature, but triple bonds between carbons, called alkynes, are not. When alkynes...
Bioorthogonal chemistry was pioneered by Dr. Carolyn Bertozzi, a 2017 inductee into the National Inventors Hall of Fame. Her work in Immunology earned her--
Alkenes & Alkynes - Crash Course Chemistry #41 - lesson plan ideas from Spiral. Tagged under: Chemistry (Professional Field),crash ,chemistry,molecule,energy,chemical bonds,Leucippus,atomic theory, nucleus,organic chemistry,Organic Chemistry (Field Of Study),alkanes,isomers,structure,alkenes,alkynes,naming rules,cis trans isomerism,hydrogenation,halogenation,polymerization,triglycerides,names fats
Toxicocinétique et métabolisme Lalcool propargylique (Propargil Alkol, Propargyl Alcohol) est probablement métabolisé en aldéhyde propargylique. Cette oxydation a été démontrée in vitro dans des expériences avec la catalase obtenue à partir de foie de bovin. Des expériences in vitro avec des microsomes hépatiques de rats induits par le phénobarbital ont révélé de faibles niveaux de liaison de lalcool propargylique (Propargil Alkol, Propargyl Alcohol) au cytochrome P450 (BG Chemie 1999). 3 Effets chez lhomme Il ny a pas de données sur les effets chez lhomme dune exposition à lalcool propargylique (Propargil Alkol, Propargyl Alcohol). 262 Propargyl Alcohol (Propargil Alkol, Propargyl Alcohol) Volume 21 Propargyl Alcohol (Propargil Alkol, Propargyl Alcohol) 4 Expérimentation animale et études in vitro 4.1 Toxicité aiguë Lalcool propargylique (Propargil Alkol, Propargyl Alcohol) sest avéré toxique après administration orale, application cutanée et exposition par ...
LI-COR now offers a portfolio of Click Chemistry reagents for copper-catalyzed and copper-free methods. These products offer researchers flexibility to choose the correct reagent for a diverse array of applications. LI-COR Click Chemistry reagents include IRDye® 800CW, IRDye 680RD, and IRDye 650 infrared fluorescent dyes labeled with DBCO, azide, or alkyne groups. Click Chemistry utilizes pairs of reagents that exclusively react with each other and are effectively inert to naturally-occurring functional groups such as amines. Unlike affinity interactions such as streptavidin-biotin, Click Chemistry forges covalent bonds between the reacting partners to deliver stable bioconjugates.. Click Chemistry reactions can be categorized into two separate groups, copper-catalyzed or copper-free. Copper-catalyzed Click Chemistry is used for initiating reactions between azides and alkynes. These reactions are also known as Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC). Although they initiate and ...
LI-COR now offers a portfolio of Click Chemistry reagents for copper-catalyzed and copper-free methods. These products offer researchers flexibility to choose the correct reagent for a diverse array of applications. LI-COR Click Chemistry reagents include IRDye® 800CW, IRDye 680RD, and IRDye 650 infrared fluorescent dyes labeled with DBCO, azide, or alkyne groups. Click Chemistry utilizes pairs of reagents that exclusively react with each other and are effectively inert to naturally-occurring functional groups such as amines. Unlike affinity interactions such as streptavidin-biotin, Click Chemistry forges covalent bonds between the reacting partners to deliver stable bioconjugates.. Click Chemistry reactions can be categorized into two separate groups, copper-catalyzed or copper-free. Copper-catalyzed Click Chemistry is used for initiating reactions between azides and alkynes. These reactions are also known as Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC). Although they initiate and ...
Photo-mediated copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reactions for forming polymer networks as shape memory materials Journal Article ...
If you have a question about this talk, please contact .. The development of bioorthogonal reactions made it possible to visualize and study biomolecules in their native cellular context and contributed to advanced targeted drug delivery strategies. In our research group we are interested in developing novel bioorthogonal chemistry and apply this in the targeting of specific cell types. We recently added non-strained, highly soluble and stable vinylboronic acids (VBA) as reactants to the bioorthogonal toolbox which react with tetrazines in an inverse-electron demand Diels-Alder reaction. We have observed exceptional high reaction rates between non-strained vinylboronic acids (VBAs) and dipyridyl tetrazines relative to that of tetrazines lacking such dative coordinating ligand. As VBAs are mild Lewis acids, we hypothesize that coordination of the pyridyl to the boronic acid promotes the tetrazine ligation. In the current presentation, we explore the scope and molecular origins of the observed VBA ...
Nominated Substances: Propargyl alcohol. Nomination Date: 09/20/1996 Nominator: NCI Rationale: Propargyl alcohol is nominated for subchronic studies based on potential for human exposure and a suspicion of carcinogenicity. Propargyl alcohol is a high production volume chemical which is used mainly as a chemical intermediate for a variety of products. It has been identified in air, soil and solid waste. The suspicion of carcinogenicity is based on its metabolism to the aldehyde and positive results in genotoxicity studies. The hepatotoxicity observed in previous studies is similar to that produced by carbon tetrachloride. Chronic toxicity data is lacking. NTP Principles: 1, 2, 7. ...
Highlights Ni-Catalyzed Coupling Reactions Nickel-Catalyzed Coupling of Carbonyl Compounds and Alkynes or 1,3-Dienes: An Efficient Method for the Preparation of Allylic, Homoallylic, and Bishomoallylic Alcohols Shin-ichi Ikeda* Keywords: alcohols · C C coupling · catalysis · multicomponent reactions · nickel The alkenylation, allylation, and homoallylation of carbonyl compounds, which gives allylic, homoallylic, and bishomoallylic alcohols, respectively, are important processes in the formation of carbon-carbon bonds. However, in these approaches, the preparation of the corresponding alkenylating, allylating, and homoallylating reagents, which often requires troublesome procedures, is unavoidable.[1-5] Recently, new nickelcatalyzed coupling reactions of a carbonyl compound (e.g., aldehyde or ketone) and an unsaturated substrate (e.g., alkyne or 1,3-diene) with an organometallic or metal hydride have been reported, and these offer more efficient methods to give the desired alcohols without ...
Kataria, Meenal ; Deol, Harnimarta ; Singh, Gurpreet ; Kumar, Manoj ; Bhalla, Vandana (2018) Visible-light-mediated dehydrogenative cross-coupling between terminal alkynes and aldehydes by employing a supramolecular polymeric ensemble of PBI derivative New Journal of Chemistry, 42 (2). pp. 822-826. ISSN 1144-0546 Full text not available from this repository.. Official URL: http://pubs.rsc.org/en/content/articlelanding/2018.... Related URL: http://dx.doi.org/10.1039/C7NJ03557H ...
TY - JOUR. T1 - Isolated, well-defined organovanadium(III) on silica. T2 - Single-site catalyst for hydrogenation of alkenes and alkynes. AU - Sohn, H.. AU - Camacho-Bunquin, J.. AU - Langeslay, R. R.. AU - Ignacio-De Leon, P. A.. AU - Niklas, J.. AU - Poluektov, O. G.. AU - Liu, C.. AU - Connell, J. G.. AU - Yang, D.. AU - Kropf, J.. AU - Kim, H.. AU - Stair, P. C.. AU - Ferrandon, M.. AU - Delferro, M.. PY - 2017/1/1. Y1 - 2017/1/1. N2 - A well-defined, isolated, single-site organovanadium(iii) catalyst on SiO2 [(SiO2)V(Mes)(THF)] was synthesized via surface organometallic chemistry, and fully characterized using a combination of analytical and spectroscopic techniques (EA, ICP, 1H NMR, TGA-MS, EPR, XPS, DR-UV/Vis, UV-Raman, DRIFTS, XAS). The catalyst exhibits unprecedented reactivity in liquid-and gas-phase alkene/alkyne hydrogenation. Kinetic poisoning experiments revealed that 100% of the V sites are active for hydrogenation.. AB - A well-defined, isolated, single-site organovanadium(iii) ...
Rules for naming alkynes (molecules with a carbon-carbon triple bond). Created by Jay. Watch the next lesson: https://www.khanacademy.org/science/organic-chemistry/alkenes-alkynes/naming-preparation-alkynes/v/alkyne-acidity-and-alkylation?utm_source=YT&utm;_medium=Desc&utm;_campaign=organicchemistry Missed the previous lesson? https://www.khanacademy.org/science/organic-chemistry/alkenes-alkynes/alkene-reactions-tutorial/v/ozonolysis-1?utm_source=YT&utm;_medium=Desc&utm;_campaign=organicchemistry Organic Chemistry on Khan Academy: Carbon can form covalent bonds with itself and other elements to create a mind-boggling array of structures. In organic chemistry, we will learn about the reactions chemists use to synthesize crazy carbon based structures, as well as the analytical methods to characterize them. We will also think about how those reactions are occurring on a molecular level with reaction mechanisms. Simply put, organic chemistry is like building with molecular Legos. Lets make some
Huge advances have been made in the field of palladium catalyzed C-H activation in the past decade. The application of palladium catalyzed C-H activation to form complex, multifunctional substrates, especially directly C-H alkynylation are positively exploring. We have recently successfully elucidated a series of palladium catalyzed C-H alkynylation from commercial available material. These transformations included synthesis of highly substituted cyclopentadiene fused chromones from cascade reactions of coumarins with alkynes and C¿H/N¿H dual activation to synthesize benzazepines from isatin and alkynes; Recent years have witnessed an explosive growth in the field of iminium and enamine catalysis. Primary and secondary amines as catalysis in the cycloaddition transformation of biological and pharmaceutical compounds via the iminmium activation model have been greatly explored. We have successfully explored a series of enamine catalyzed [3+2] cycloaddition. These pioneering works consisted by ...
The Sonogashira reaction is a cross-coupling reaction used in organic synthesis to form carbon-carbon bonds. It employs a palladium catalyst to form a carbon-carbon bond between a terminal alkyne and an aryl or vinyl halide. R − ≡ − H + R ′ − X → base, rt Pd cat., Cu cat. R − ≡ − R ′ {\displaystyle {\begin{matrix}{}\\{\ce {R-\!{\equiv }\!-H}}+{\color {Red}{\ce {R}}}\!-\!{\ce {X->[{\text{Pd cat., Cu cat.}}][{\text{base, rt}}]R-\!{\equiv }\!}}{\color {Red}{\ce {-R}}}\end{matrix}}} R: Aryl or Vinyl X: I, Br, Cl or OTf The Sonogashira cross-coupling reaction has been employed in a wide variety of areas, due to its usefulness in the formation of carbon-carbon bonds. The reaction can be carried out under mild conditions, such as at room temperature, in aqueous media, and with a mild base, which has allowed for the use of the Sonogashira cross-coupling reaction in the synthesis of complex molecules. Its applications include pharmaceuticals, natural products, organic materials, ...
The Sonogashira reaction is a cross-coupling reaction used in organic synthesis to form carbon-carbon bonds . It employs a palladium catalyst to form a carbon-carbon bond between a terminal alkyne and an aryl or vinyl halide . The Sonogashira cross-coupling reaction has been employed in a wide variety of areas, due to its usefulness in the formation of carbon-carbon bonds. The reaction can be carried out under mild conditions, such as at room temperature, in aqueous media, and with a mild base, which has allowed for the use of the Sonogashira cross-coupling reaction in the synthesis of complex molecules. Its applications include pharmaceuticals, natural products, organic materials, and nanomaterials. Specific examples include its use in the synthesis of tazarotene , which is a treatment for psoriasis and acne , and in the preparation of SIB-1508Y, also known as Altinicline , which is a potential treatment for Parkinson's disease , Alzheimer's disease , Tourette syndrome , schizophrenia ,
The 1,3-dipolar cycloaddition of trifluoromethylated propargylic alcohols 1 with azides in the presence of catalytic [Cp*RuCl2], afforded exclusively 4-trifluoroniethyl-1,4,5-trisubstituted-1,2,3-triazoles 2 in high yields. (c) 2008 Elsevier Ltd. All rights reserved ...
see article for more reactions. Abstract. A highly efficient oxidation of propargylic alcohols to ynones is catalyzed by copper nanoparticles (Cu Nps) with TBHP or air as oxidants. With bipyridine as the ligand, the reaction was accelerated significantly and led in good to excellent yields to a variety of propargylic alcohols.. ...
Mild and efficient synthesis of ynones via Ir(III)- and Rh(III)-catalyzed, chelation-assisted formyl C-H alkynylation of benzaldehydes has been achieved using hypervalent iodine-alkyne reagents. Rhodium and iridium catalysis exhibited complementary substrate scope ...
Speziali MG, Monteiro AL. Synthesis of Imidazole-Derived Ionic Liquids from Monoterpenes by Means of the Sonogashira Reaction. Synthesis-StuttgartSynthesis-StuttgartSynthesis-Stuttgart. 2012;44:3505-3511.
Prof. Echavarrens group presents the first general enantioselective synthesis of cyclobutenes by intermolecular [2+2] cycloadditions. Digold complexes catalyse the reaction between terminal alkynes and alkenes leading to chiral cyclobutenes, useful in organic chemistry because they can be hydrogenated into functionalised cyclobutanes, which are motifs present in a variety of natural products and pharmaceuticals.. Previous attempts to achieve this transformation required activated alkynes or strained alkenes. The new strategy developed at ICIQ works for an enormous variety of terminal alkynes and a myriad of both disubstituted and trisubstituted alkenes. In total, this gold-catalysed reaction was used to synthesize a scope of over 40 different products, all with good yields and excellent enantiomeric ratios.. Due to the linear geometry of gold(I) complexes, chiral ligands are usually far away from the reaction centre. Hence, finding the gold catalysts that yield enantioselective transformations ...
M. Konkol, H. Schmidt, D. Steinborn, J. Mol. Catal. A: Chemical 2007, 261, 301 - 305. „Iridium-catalyzed addition of methanol to internal alkynes. ___________________________________________________________. M. Konkol, H. Schmidt, D. Steinborn, J. Mol. Catal. A: Chemical 2007, 269, 119 - 124. „Iridium-catalyzed addition of methanol to terminal alkynes ___________________________________________________________. M. Vavra, I. Potočň k, M. Dušek, K. Fejfarov , C. Wagner, D. Steinborn, Achievements in Coordination, Bioinorganic and Applied Inorganic Chemistry (Eds. M. Melnik, J. ima, M. Tatarko), STU Press, Bratislava, 2007, 333 - 344 ...
Organic compounds that contain nitrogen are very important intermediates in pharmaceutical and chemical industry. Hydroamination is the reaction that can form C-N bond with high atom economy. The research progress in metals catalyzed hydroamination of alkenes and alkynes from the perspective of reaction mechanism is categorized and summarized.
Mentioning: 12 - An efficient protocol for the direct transformation of chroman-4-ones to tricyclic fused pyridines with the skeleton of cassiarins, a family of alkaloids with antimalarial activity, was developed. Also, a general strategy for modular construction of polyheterocycles with diverse natural product-like skeletons was developed by using ketone-alkyne bifunctional substrates. These reactions involved a one-pot cascade oximation of ketones, rhodium-catalyzed C-H activation, and intermolecular/intramolecular alkyne annulations under mild conditions with high atom, step, and redox economy.
A catalytic hydroamidation of alkynes with isocyanates using alkyl bromides as hydride sources has been developed. The method turns parasitic β-hydride elimination into a strategic advantage, rapidly affording acrylamides with excellent chemo- and regioselectivity.. ...
A series of bis(amidate)group 4-bis(amido) complexes have been prepared, characterized and have been shown to be highly tunable precatalysts for both the intra- and intermolecular hydroamination of alkynes.. ...
TY - JOUR. T1 - Naphthoquinones from alkynes and chromium-carbene complexes-control of regioselectivity through intramolecular reaction. AU - Semmelhack, Martin F.. AU - Bozell, Joseph J.. PY - 1982/1/1. Y1 - 1982/1/1. N2 - A series of carbene-chromium complexes bearing a phenyl substituent and an alkoxy-alkyne substituent have been prepared by acetoxy replacement. Intramolecular cycloaddition with carbon monoxide insertion occurs to provide naphthohydroquinones in good yield.. AB - A series of carbene-chromium complexes bearing a phenyl substituent and an alkoxy-alkyne substituent have been prepared by acetoxy replacement. Intramolecular cycloaddition with carbon monoxide insertion occurs to provide naphthohydroquinones in good yield.. UR - http://www.scopus.com/inward/record.url?scp=0000695788&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0000695788&partnerID=8YFLogxK. U2 - 10.1016/S0040-4039(00)87497-3. DO - 10.1016/S0040-4039(00)87497-3. M3 - Article. AN - ...
A novel strategy to obtain side chain modified poly(oxindole biphenylylene) (POXI) by photoinduced copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction is described. In the first step, an alkyne-functionalized poly(oxindolebiphenylylene) (POXI-alkyne) is synthesized by superacid-catalyzed condensation of isatin with aromatic hydrocarbons. Subsequently, poly(ethylene glycol) methyl ether (Me-PEG), 1-pyrenemethanol (Py-OH) and 1,3-dibromopropane (DBP) are functionalized by azide groups via simple nucleophilic substitution reaction. Visible-light-induced CuAAC reaction between POXI-alkyne and the corresponding azide functionalized click components employing dibenzoyldiethylgermane (DBDEG) as photoactivator resulted in the formation of POXI-PEG, POXI-Py and insoluble network, respectively. Successful modification of POXI was confirmed by the spectral, (1H NMR, FT-IR, Fluorescence), chromatographic (GPC) and thermal (DSC) investigations ...
Interdisciplinary Nanoscience Center - INANO-Fysik, iNANO-huset, Interdisciplinary Nanoscience Center, Science and Technology, Aarhus ...
TY - JOUR. T1 - Precise grafting of macrocyclics and dendrons to a linear polymer chain. AU - Amir, Faheem. AU - Hossain, Md D.. AU - Jia, Zhongfan. AU - Monteiro, Michael J.. PY - 2016/8/31. Y1 - 2016/8/31. N2 - Sequential growth of multifunctional telechelic polymer chains was used here to produce three, four or seven HO-functionalities equally spaced along the polymer backbone. The telechelic building block consisted of a halide group on one end and both a hydroxyl and alkyne group on the other end. The key was to maintain the halide end-group on the telechelic polymer chain during the CuAAC coupling reaction after each sequential growth. This was accomplished by using the combination of the PMDETA ligand and toluene as a solvent to produce significantly faster rates of CuAAC coupling reaction over halide abstraction. The HO-functionalities were then converted to azide groups allowing further CuAAC reactions with either alkyne polymeric dendrons or cyclics to produce equally spaced grafts ...
Free Notes on Alkanes, Alkenes and Alkynes - KCET Engineering. Read all the Important points and Chapterwise Notes on KCET Engineering
Reactions of 2-pyrone (2P) and 1,4-oxazinone (OXZ) with hetero alkynes viz., phosphines (HA1) and silanes (HA2) have been scanned at B3LYP/6-31G(d) level.
Acetylene is a weak acid, but not nearly as weak as alkanes or alkenes. CompoundpK a HF3.2 H 2 O16 NH CH 4 60 H2CH2CH2CH2C CH 2 HCCH 26 Acetylene
These are dPEG® compounds from Quanta Biodesign that contain discrete length PEGs. This can improve reproducibility in experiments when compared to using PEGs of variable length. PEGS have high aqueous solubility and a substances aqueous solubility can be improved by attaching a PEG. Some of these compounds contain a single reactive end for attachment to proteins such as through amines or sulfhydryls. This list includes branched PEGs which are more compact than long linear PEGs. There are also compounds with two reactive ends for crosslinking. Some of the compounds have azide groups which can be attached to alkynes using copper click chemistry or to strained alkynes through copper-free click chemistry. Some of the compounds have a biotin on one end for capture by avidins. Overall the many options offered by these dPEG® products can enable a variety of biconjugation applications.
Vancomycin is the last resort antibiotic against MRSA. Vancomycin causes the bacteria to die by physically blocking a recognition site within the cell wall. This recognition site binds to the inner cavity of vancomycin, which consists of a rigid bicyclic structure. The objective of my research was to mimic this ... read more bicyclic structure using synthetic alkene and alkyne bridges, and to see if a similar cavity was obtained. The alkene bridges were introduced using a (tandem) ring-closing metathesis reaction and the alkyne bridges were introduced by a Sonogashira reaction. show less ...
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The copper (I)-catalyzed alkyne azide 1,3-dipolar cycloaddition (CuAAC) or click reaction, is a highly versatile reaction that can be performed under a variety of reaction conditions including various solvents, a wide pH and temperature range, and using different copper sources, with or without additional ligands or reducing agents. This reaction is highly selective and can be performed in the presence of other functional moieties. The flexibility and selectivity has resulted in growing interest in the application of CuAAC in various fields. In this review, we briefly describe the importance of the structural folding of peptides and proteins and how the 1,4-disubstituted triazole product of the CuAAC reaction is a suitable isoster for an amide bond. However the major focus of the review is the application of this reaction to produce peptide conjugates for tagging and targeting purpose, linkers for multifunctional biomacromolecules, and reporter ions for peptide and protein analysis.
Two types of multiarm star block copolymers: (polystyrene)(m)-poly(divinylbenzene)-poly(methyl methacrylate)(n), (PS)(m),-polyDVB-(PMMA)(n) and (polystyrene)(m)-poly(divinylbenzene)-poly(tert-butyl acrylate)(k), (PS)(m)-polyDVB-(PtBA)(k) were successfully prepared via a combination of cross-linking and Diels-Alder click reactions based on arm-first methodology. For this purpose, multiarm star polymer with anthracene functionality as reactive periphery groups was prepared by a cross-linking reaction of divinyl benzene using a-anthracene end functionalized polystyrene (PSAnth) as a macroinitiator. Thus, obtained multiarm star polymer was then reacted with furan protected maleimide-end functionalized polymers: PMMA-MI or PtBA-MI at reflux temperature of toluene for 48 h resulting in the corresponding multiarm, star block copolymers via Diels-Alder click reaction. The multiarm star and multiarm star block copolymers were characterized by using H-1 NMR, SEC, Viscotek triple detection SEC (TD-SEC) ...
0)non-5-ene (DBN). 14). 14 Tertiary-amine-catalyzed thiol-isocyanate click reaction. 3 Thiol-Michael Addition Click Reactions Hydrothiolation of C==C double bond can be performed in the presence of mild bases or using nucleophilic catalysis. Unlike thiol-ene radical reaction (which can proceed with almost all olefins), thiol Michael addition reactions require activated carbon-carbon double bonds, which are in conjugation with an EWG. In the presence of trialkylamine bases such as NEt3 , the reaction proceeds smoothly to give the addition products in very high yields. This family includes 15 isoenzymes (I-XIV, V further subclassified as VA and VB) endowed with different molecular features, cellular localization, distribution in organs and tissues, and kinetic properties. It has been demonstrated that the dysfunction of these enzymes is related to different pathologies such as cancer (CAs VII, IX, XII), neurodegeneration (CA VIII), obesity (CAs VA and VB), and sterility (CA XIII) [36]. 3). 76) ...
The therapeutic efficacy of antibodies can be successfully improved through targeted delivery of potent cytotoxic drugs in the form of antibody-drug conjugates. However, conventional conjugation strategies lead to heterogeneous conjugates with undefined stoichiometry and sites, even with considerable batch-to-batch variability. In this study, we have developed a chemo-enzymatic strategy by equipping the C-terminus of anti-CD20 ofatumumab with a click handle using Sortase A, followed by ligation of the payload based on a strain-promoted azide-alkyne cycloaddition to produce homogeneous conjugates. The resulting antibody-drug conjugates fully retained their antigen binding capability and proved to be internalized and trafficked to the lysosome, which released the payload with a favorable efficacy in vitro and in vivo. Thus, this reported method is a versatile tool with maximum flexibility for development of antibody-drug conjugates and protein modification.
Methods for selective protein imaging are critical for elucidating how cells orchestrate fundamental biological processes. We recently developed a chemoenzymatic method to modify bacterial proteins in situ for fluorescence imaging using N-myristoyl transferase (NMT). Target proteins outfitted with an N-terminal NMT recognition sequence are covalently modified with an azido fatty acid. Subsequent strain-promoted azide-alkyne cycloaddition allows for conjugation to cell-permeant fluorophores and imaging by fluorescence microscopy. Here we describe sample preparation and labeling protocols for imaging bacterial proteins in fixed and live cells. ...
Prof. Aiwen Lei and coworkers, Wuhan University, Hubei, have developed a silver catalyst click reaction for the synthesis of pyrrole, by cycloaddition. This system benefits from readily-available starting materials, low catalyst loading (0.1 eq), short reaction times (2 h) and excellent chemo-selectivity. And, works for both internal and alkyl substituted terminal alkynes in the presence of many functional groups. The extremely mild conditions used, makes this reaction synthetically attractive ...
0018] Compounds of formula (I) and (III) wherein the vector is a peptide or protein may be prepared by standard methods of peptide synthesis, for example, solid-phase peptide synthesis, for example, as described in Atherton, E. and Sheppard, R. C.; Solid Phase Synthesis; IRL Press: Oxford, 1989. Incorporation of the alkyne or azide group in a compound of formula (I) or (III) may be achieved by reaction of the N or C-terminus of the peptide or with some other functional group contained within the peptide sequence, modification of which does not affect the binding characteristics of the vector. The alkyne or azide groups are preferably introduced to a compound of formula (I) or (III) by formation of a stable amide bond, for example formed by reaction of a peptide amine function with an activated acid or alternatively reaction of a peptide acid function with an amine function and introduced either during or following the peptide synthesis. Methods for incorporation of the alkyne or azide group ...