• Significant advances in metal-catalyzed reactions, especially cyclizations, have dramatically improved the efficiency of organic synthesis over the last three decades. (thieme.de)
  • Science of Synthesis: Metal-Catalyzed Cyclization Reactions" presents the most commonly used and significant metal-catalyzed reactions for modern organic synthesis. (thieme.de)
  • Also included are cyclization reactions of alkenes, alkynes, and allenes, cycloisomerizations, and intramolecular C-N and C-O bond formation. (thieme.de)
  • Ruchirawat, S., PIFA-BF 3· OEt 2 mediated intramolecular regioselective domino cyclization of ynamides: A novel method for the synthesis of tetrahydroisoquinoline-oxazol-2 (3H)-ones. (cgi.ac.th)
  • Ruchirawat, S., Silver-Catalyzed Cyclization of ortho-Carbonylarylacetylenols for the Synthesis of Dihydronaphthofurans. (cgi.ac.th)
  • Transition metal free hydrolysis/cyclization strategy in a single pot: synthesis of fused furo N-heterocycles of pharmacological interest. (gu.se)
  • When an aromatic ring-substituted alkyne was used, 2-furanone derivatives were selectively obtained via 5-exo-dig cyclization, whereas the reaction of alkyl-substituted alkynes produced 2-pyrone derivatives with high selectivity. (elsevier.com)
  • C-C bond-forming carboxylation and cyclization of trimethyl(2-methylenebut-3-yn-1-yl)silane derivatives and carbon dioxide was developed. (elsevier.com)
  • Sekine, K, Sadamitsu, Y & Yamada, T 2015, ' SilverCatalyzed Cascade Carboxylation and Cyclization of Trimethyl(2-methylenebut-3-yn-1-yl)silane Derivatives ', Organic Letters , vol. 17, no. 22, pp. 5706-5709. (elsevier.com)
  • The first cis,cis,cis,trans-[5.5.5.5]-fenestranes have been synthesized in three steps using a novel arene-alkene photocycloaddition-radical cyclization cascade, which creates overall 5 new rings and 8 stereogenic centers. (elsevier.com)
  • ChemInform Abstract: A Quantitative Study of Substituted Effects on Oxidative Cyclization of Some 2-Aryl-substituted Aldehyde Thiosemicarbazones Induced by Ferric Chloride and Cupric Perchlorate. (scite.ai)
  • A proposed universal monoterpene synthases (cyclases) cyclization mechanism topologically requires an isomerization step of the substrate geranyl diphosphate (GPP) to the formation of the proposed universal intermediate linalyl diphosphate (LPP), which has never been directly observed. (brandeis.edu)
  • The study described here was designed to investigate the cyclization mechanism by studying a model enzyme, (4R)-(+)-limonene synthase ((+)-LS), a monoterpene cyclase that produces (+)-limonene by using substrate GPP. (brandeis.edu)
  • Access 5 Monosaccharides - Cyclization video and text solutions to help you complete your homework. (clutchprep.com)
  • Watch our Monosaccharides - Cyclization learn videos . (clutchprep.com)
  • A new synthetic approach to thieno[2,3-d]imidazoles is presented on the basis of the N′-(3-halothiophen-2-yl)amidine cyclization under copper-catalyzed cross-coupling. (enamine.net)
  • When cyclization was induced in deuterated acid, the trans, trans-diene gave 2^t, 3^c-dlmethyl-4-deuterocyclohexyl^c formate, while the cis, cis-isomer produced the C-4 epimer. (caltech.edu)
  • Cyclization of N-(2-aryl-2-cyclohexen-1-yl)trichloroacetamides by a copper catalyst was investigated. (elsevier.com)
  • It is crucially important for successful cyclization under mild conditions that alkoxycarbonyl groups are introduced to the nitrogen atom of the N-allyltrichloroacetamides as well as that CuCl- (bipyridine) is used as the catalyst. (elsevier.com)
  • In the final step, the target cyclodipeptide is obtained through intramolecular cyclization. (nature.com)
  • Chuang, T.-H. Hypervalent Iodine(III)-Induced Domino Oxidative Cyclization for the Synthesis of Cyclopenta[ b ]furans. (mdpi.com)
  • Primary alcohols undergo oxidative cyclization without significant oxidation to the aldehyde, a fact that illustrates the range of reactivity available from various Pd(II) salts under differing conditions. (caltech.edu)
  • The cyclization reactions lead to products having stereochemistry that is directly analogous to oxidative cyclization reactions utilizing ketene dithioiacetal radical cations and alcohol trapping groups. (wustl.edu)
  • There is compelling experimental and theoretical evidence for formation of nondirect sequence ions via cyclization/reopening chemistry in the CID spectra of the b tons when the His residue is near the C-terminus. (springer.com)
  • Paramita Das and Chhanda Mukhopadhyay, "Microwave Irradiation for Catalyst and Solvent Free Knoevenagel/Michael Addition/Cyclization/Aromatization Cascades", Current Microwave Chemistry (2014) 1: 98. (eurekaselect.com)
  • Wenkert, Ernest (1980) A formylation-cyclization method of synthesis of cycloalkenones from unsaturated ketones Journal of Organic Chemistry, 45 (6). (ias.ac.in)
  • The iodine-catalyzed Prins cyclization of homoallylic alcohols and aldehydes was investigated under metal-free conditions and without additives. (mdpi.com)
  • Under similar conditions, the Prins cyclization of six alcohols containing an endocyclic double bond (primary, secondary, or tertiary) led to dihydropyrans in 52%-91% yield. (mdpi.com)
  • Reddy KR, Rosa IML, Doriguetto AC, Bastos EL, Silva LF Jr (2013) Iodine-catalyzed prins cyclization of homoallylic alcohols and aldehydes. (springer.com)
  • Naphthopyrans and their C4 Alcohols by Cyclization of Substituted Naphthalenes using Potassium t-Butoxide in Dimethylformamide. (edu.au)
  • Enantioselective cyclization of enamide-ynes and application to the synthesis of the kopsifoline core. (biomedsearch.com)
  • We report the palladium-catalyzed enantioselective cyclization of 1,6-enamidynes to form spirocyclic ring systems. (biomedsearch.com)
  • Nickel-catalyzed additions of arylboronic acids to alkynes, followed by enantioselective cyclizations of the alkenylnickel species onto tethered ketones or enones, are reported. (nottingham.ac.uk)
  • The group publishes a novel approach to enantioselective polyene cyclizations via organo-SOMO catalysis. (princeton.edu)
  • In addition, the alkyne aza-Prins cyclization between homopropargyl tosylamine and aldehydes gives 2-alkyl-4-halo-1-tosyl-1,2,5,6-tetrahydropyridines as the only cyclic products. (csic.es)
  • Chapter 1 gives an introduction to tungsten catalysis and its application in the formation of heterocycles via cyclization of alkyne derivatives. (ntu.edu.sg)
  • In addition, pyrroles, pyridines and isoquinolines were also efficiently synthesized via cyclization of alkyne derivatives tethered to nitrogen nucleophiles under thermal conditions in the presence of tungsten catalysis. (ntu.edu.sg)
  • Stephen Hashmi and co-workers have reported in ACIE on a cyclization of an alkyne to form a benzofuranone. (wordpress.com)
  • CLIPS (Chemical Linkage of Peptides onto Scaffolds) Cyclization is an integrated technology that combines chemical linkage of a linear peptide to a synthetic scaffold with conformational fixation of the peptide. (creative-peptides.com)
  • As a technology for peptide cyclization, the CLIPS TM (Chemically Linked Peptides on Scaffolds) has been applied successfully in identifying the epitope on human CD20 and reconstructing the conformational epitope on follicle stimulating hormone. (creative-peptides.com)
  • CLIPS Cyclization can be used for conformational fixation of free peptides in solution, while it also applies to solid-phase attached peptides in microarrays used for antibody-screening. (creative-peptides.com)
  • Macrocyclic peptides are classified into three groups by cyclization style: sidechain-to-sidechain, head-to-sidechain, and head-to-tail (backbone) cycles are all found in natural products. (frontiersin.org)
  • Naturally occurring backbone macrocyclic peptides are generally matured from their linear counterparts by their specific cyclases, some of which have substrate promiscuity, and may be utilized for cyclization of other peptides. (frontiersin.org)
  • 25. Asymmetric Organocatalyzed Cyclization Reactions (Liu-Zhu Gong, Jun Jiang, Meng-Xia Xue, and Shi-Wei Luo). (organic-chemistry.org)
  • Rapid and quantitative cyclization of multiple peptide loops onto synthetic scaffolds for structural mimicry of protein surfaces. (creative-peptides.com)
  • The first approach was based on a highly trans-stereoselective (82% d.e.) intramolecular N-acyliminium ion cyclization of N-terminal peptide glyoxylamides, assembling the complete molecular skeleton in a single step. (dtu.dk)
  • The cyclization of the peptide around a metal core was shown to greatly increase the affinity of the peptide for its target. (umsystem.edu)
  • The primary problem with the cyclization of the peptide is the fact that two main products are produced. (umsystem.edu)
  • Backbone cyclization is a strategy that we developed to improve drug-like properties of linear peptide leads without jeopardizing the integrity of functionally relevant side-chains. (eurekaselect.com)
  • This article aims at reviewing the utilities of ene cyclization reactions for the synthesis of various ring sizes of oxygen, nitrogen and sulfur heterocycles. (rsc.org)
  • A highly efficient iron-catalyzed approach to polysubstituted pyrroles has been developed through the [4C+1N] cyclization of 4-acetylenic ketones with primary amines , leading to the synthesis of a variety of tetra- and fully-substituted pyrroles as well as fused pyrrole derivatives in good to excellent yields. (rsc.org)
  • Computational studies have been performed on potassium alkoxide-allenes, as well as potassium and lithium amido-allenes to probe the mechanism of their cyclizations to dihydrofurans and to 2,5-dihydropyrroles. (strath.ac.uk)
  • The energy profiles for 4-exo-trig cyclizations onto the allenes are also explored, and the preferred formation of the observed five-membered products is rationalized. (strath.ac.uk)
  • They have been postulated to be derived from germacranolides, but for years no progress has been made in the elucidation of their biosynthesis that requires an unknown cyclization mechanism. (nature.com)
  • Prins cyclization of isoprenol with benzaldehyde as a model aldehyde was performed using montmorillonite K10 as an acid catalyst. (springer.com)
  • Yheng K, Liu X, Qin S, Xie M, Lin M, Hu C, Feng X (2012) Completely OH-selective FeCl3-catalyzed Prins cyclization: highly stereoselective synthesis of 4-OH-tetrahydropyrans. (springer.com)
  • More GP, Rane M, Bhat SV (2012) Efficient Prins cyclization in environmentally benign method using ion exchange resin catalyst. (springer.com)
  • Yadav JS, Reddy BVS, Kumar NGGKS, Aravind S (2008) The 'aqueous' Prins cyclization: a diastereoselective synthesis of 4-hydroxytetrahydropyran derivatives. (springer.com)
  • Yadav JS, Reddy BVS, Chaya DN, Kumar NGGK, Naresh P, Jagadeesh B (2009) Heteropoly acid-catalyzed aza-Prins-cyclization: an expeditious synthesis of 4-hydroxypiperidines. (springer.com)
  • A new iron(III) halide-promoted aza-Prins cyclization between γ,δ-unsaturated tosylamines and aldehydes provides six-membered azacycles in good to excellent yields. (csic.es)
  • Conversion of Protein Active Regions into Peptidomimetic Therapeutic Leads Using Backbone Cyclization and Cycloscan - How to Do it Yourself! (eurekaselect.com)
  • A long-standing proposal envisaged electron transfer from dimsyl anions (formed by deprotonation of the solvent DMSO) but this pathway shows an exceptionally high kinetic barrier, while direct 5-endo-trig cyclization of the alkoxides and amides is much more easily achievable. (strath.ac.uk)
  • Chapter 2 describes the tungsten-catalyzed cyclization of N-propargylic amides to afford the corresponding oxazolines or oxazines via 5-exo-dig or 6-endo-dig mode. (ntu.edu.sg)
  • Oxidation and cyclization of casbene in the biosynthesis of Euphorbia factors from mature seeds of Euphorbia lathyris L. (pnas.org)
  • Here, we describe the discovery of a biosynthetic route in Euphorbia lathyris L. (caper spurge) in which regio-specific oxidation of casbene is followed by an unconventional cyclization to yield jolkinol C, a probable key intermediate in the biosynthesis of macrocyclic diterpenes, including ingenol mebutate. (pnas.org)
  • However, when considering the atom economy it has to be mentioned that the Pschorr cyclization has often only low yields. (wikipedia.org)
  • The cascade cyclization leads to an increase in molecular complexity to furnish naphtho[1,2-d]triazoles in satisfactory yields. (biomedsearch.com)
  • It is important to note that the Au(I)-catalyzed cyclization proceeds in high yields in a sterically congested environment. (beilstein-journals.org)
  • However, one might recognize that the low chemical yields encountered in some steps undermine the efficacy of the Au(I)-catalyzed cyclization approach. (beilstein-journals.org)
  • The primary peroxide adducts subsequently undergo intramolecular Diels-Alder (IMDA) cyclization, affording a number of diastereomeric tricyclic adducts that have characteristic carbonyl (13)C chemical shifts at ~198 ppm. (sigmaaldrich.com)
  • In contrast, cyclizations of deuterium-labeled carboxylic acid substrates undergo anti oxypalladation. (caltech.edu)
  • This cyclization is less favoured due to the electron donating ability of the nitrogen atom, causing the pentadienyl cation to be relatively stable and unwilling to undergo cyclization. (smu.ca)
  • It is hypothesized that by doing so the addition of an acid will form the cyclopentadienyl cation that will readily undergo Nazarov cyclization. (smu.ca)
  • Although the cyclization of enol ether 5 can produce 5- exo and 6- endo products, we found that gold complexes 6 , having bulky phosphine ligands such as 2-bis( tert -butylphosphino)biphenyl, gave exclusively the 6- endo-dig cyclized products 7 ( Scheme 1 ). (beilstein-journals.org)
  • The second derivative of Fourier transform infrared and Gaussian fitting was used to analyze the tapes cyclization due to stabilization treatment through introducing I sd index. (deepdyve.com)
  • Pascal begins with the assumption that terminal aryl substitution on the enediyne will both (a) inhibit the C 1 -C 6 cyclization due to steric interactions and (b) the C 1 -C 5 cyclization should be enhanced due to stabilization of the radical by the neighboring aryl group. (comporgchem.com)
  • Bio-inspired acetal induced polyene cyclization : the development and applications. (ntu.edu.sg)
  • The development of a bio-inspired acetal induced intermolecular polyene cyclization is described. (ntu.edu.sg)
  • By exploiting the acetal induced intermolecular polyene cyclization, a highly efficient method to construct 8-oxabicyclo[3,2,1]octanes was discovered. (ntu.edu.sg)
  • The Nazarov cyclization is a common synthetic tool in the synthesis of cyclopentenone rings. (smu.ca)
  • The synthesis of an aryl vinyl silyl nitronate was optimized and the compound was tested with a number of different acid catalysts to determine if the nitronate Nazarov cyclization is possible. (smu.ca)
  • This entry was posted on October 1, 2015 at 6:04 am and is filed under Computational , DFT , Mechanistic , Named Reactions , Nazarov cyclization . (wordpress.com)
  • Tyrosine-lipid peroxide adducts from radical termination: para coupling and intramolecular Diels-Alder cyclization. (sigmaaldrich.com)
  • The reactions are categorized according to the nature of the internal electrophile participating in the cyclization step, i.e. carboxylic acid or its derivative, carbonyl compound, or alkylating agent. (enamine.net)
  • Unlike most cytochrome P450s, kauniolide synthase combines stereoselective hydroxylation of costunolide at the C3 position, with water elimination, cyclization and regioselective deprotonation. (nature.com)
  • The second approach aimed for the use of a cis-stereoselective intermolecular Pictet-Spengler cyclization to construct the first part of the ringsystem and a subsequent diketopiperazine formation to close the second ring. (dtu.dk)
  • The generality of the high-yielding, stereoselective cyclization of 2-allyl-3-(1? (edu.au)
  • Glycal Cyclization InBr3-Catalyzed Cyclization of Glycals with Aryl Amines** Jhillu S. Yadav,* Basi V. S. Reddy, Katta V. Rao, Kavuda Saritha Raj, Atlaluri R. Prasad, Singarapu Kiran Kumar, Ajit C. Kunwar, Panjula Jayaprakash, and Bulusu Jagannath Scheme 1. (docme.ru)
  • In the past and recent years, many exciting reports have demonstrated the broad scope and synthetic utility of ene cyclization and the versatility of oxonium ion, iminium ion and thionium ion intermediates. (rsc.org)
  • Thus, it is easy to work through 'Handbook auf Cyclization Reactions' and keep possible synthetic strategies in the back of the mind for later access when needed. (organic-chemistry.org)
  • A new synthetic approach to thieno[2,3-d]imidazoles is presented on the basis of the N′-(3-halothiophen-2-yl)amidine cyclization under copper-catalyzed cross-coupling. (enamine.net)
  • On the other hand, the other methods of cyclization use an amino acid's sidechain. (frontiersin.org)
  • Radical cyclization reactions are organic chemical transformations that yield cyclic products through radical intermediates. (wikipedia.org)
  • The ultimate and only reference source in this field, this handbook discusses the latest advances on the reactions leading to the formation of cyclic structures and includes chapters presenting the most synthetically attractive cyclization reactions. (organic-chemistry.org)
  • A novel route to cyclic imines based on 5-exo radical cyclization is explored. (diva-portal.org)
  • Nitrogen-centered radical cyclizations onto silyl enol ethers were utilized for the syntheses of protected polyhydroxylated pyrrolidines 2-hydroxymethyl-3-hydroxypyrrolidine and 1,4-dideoxy-1,4-imino-L-ribitol. (ubc.ca)
  • To improve this cyclization, the imine is replaced with the electron withdrawing nitronate functionality. (smu.ca)
  • Side reactions are sometimes a problem, and cyclization is especially slow for small and large rings (although macrocyclizations, which resemble intermolecular radical reactions, are often high yielding). (wikipedia.org)
  • Reversible Bergman cyclization. (sciencephoto.com)
  • Atomic force microscopy (AFM) image of the starting point (a brominated aromatic compound) for a reversible Bergman cyclization. (sciencephoto.com)
  • Phenyl substitution does accomplish both suggestions: the activation barrier for the Bergman cyclization increases by 4 kcal mol -1 , while the barrier for the C 1 -C 5 cyclization is lowered by nearly 6 kcal mol -1 . (comporgchem.com)
  • With BLYP, the C 1 -C 5 cyclization is favored by a significant amount over the Bergman cyclization. (comporgchem.com)
  • This indicates less active cyclization/reopening followed by fragmentation of common structures for b n ions containing His than for sequences of solely aliphatic residues. (springer.com)
  • It was found that mild aqueous conditions result in the cyclization of creatine ethyl ester to provide inactive creatinine as the exclusive product, and this transformation becomes nearly instantaneous as the pH approaches 7.4. (nih.gov)
  • This study demonstrates that mild non-enzymatic conditions are sufficient for the cyclization of creatine ethyl ester into creatinine, and together with previous results obtained under enzymatic conditions suggests that there are no physiological conditions that would result in the production of creatine. (nih.gov)
  • The second approach included two distinct routes involving an ethyl glyoxylate or a glyoxylic acid Pictet-Spengler cyclization. (dtu.dk)
  • forming the cyclopentadienyl cation that undergoes cyclization. (smu.ca)
  • Now I want to discuss lactones, lactams and cyclization reactions. (clutchprep.com)
  • To realize the strategy shown in Figure 3 , cis -bicyclo[3.3.0]octane-3,7-dione ( 1 ) [44-50] was subjected to twofold Fischer indole cyclization to generate the diindole derivative 6 by using 1-methy-1-phenylhydrazine ( 5 ) under HCl/EtOH reflux conditions. (beilstein-journals.org)
  • However, low concentrations of a radical scavenger establish thermodynamic control and provide access to 6-endo products-not via 6-endo cyclization, but by 5-exo cyclization followed by 3-exo closure and subsequent fragmentation (Dowd-Beckwith rearrangement). (wikipedia.org)
  • Despite more energetically favorable cyclization barriers for the b 5 structures, the b 4 ions experimental data show more clear evidence of cyclization and sequence scrambling before fragmentation. (springer.com)
  • Description on the cyclization-prenylation sequence. (ebscohost.com)