• Enolates of substrates having free N-H bonds undergo protodemetalation to provide ultimately the 1,4-addition adduct. (journaltocs.ac.uk)
  • This is a [2+1] cycloaddition of a carbene to an alkyne or alkene (more specifically in the Dӧtz reaction a carbene coordinated to a metal carbonyl group) to produce substituted aromatic phenols. (wikipedia.org)
  • When ketenes are formed in the presence of alkynes they proceed through pericyclic reactions to generate a substituted aromatic ring (Scheme 2). (wikipedia.org)
  • irradiation of the diazoketones induces the Wolff rearrangement yielding the vinyl ketene intermediate which reacts with the acetylene in a [2+2] cycloaddition then a four-electron cleavage of the resulting 4-substituted cyclobutenone produces a dienylketene which then undergoes a six-electron electrocyclization to give the 2,4-cyclohexanedione which tautomerizes to the final aromatic product. (wikipedia.org)
  • Upon addition of the alkyne a [2+2] cycloaddition occurs. (wikipedia.org)
  • The reaction proceeds via the formation of a benzopyrylium intermediate followed by intramolecular [4 + 2] cycloaddition and a subsequent decarboxylation pathway. (bvsalud.org)
  • A well-designed, electron deficient, and sterically hindered amide-type NN 2 pincer ligand was crucial to the success of a general, efficient, and practical nickel-catalyzed deaminative allenylation of amino acid derivatives with terminal alkynes under mild conditions. (organic-chemistry.org)
  • A CuI-catalyzed synthesis of 1,3-disubstituted allenes from 1-alkynes by the reaction with various N -tosylhydrazones as readily available starting materials is operationally simple and gives the desired products in good yields. (organic-chemistry.org)
  • 1,2,3,4-tetrahydroisoquinoline (THIQ) mediates a practical synthesis of 1,3-disubstituted allenes from terminal alkynes and aldehydes under mild conditions in the presence of CuBr first and then ZnI 2 . (organic-chemistry.org)
  • In one-step RT-PCR, cDNA synthesis via reverse transcription (RT) and subsequent PCR amplification occur in the same reaction vessel (figure made in BioRender). (stratech.co.uk)
  • We report the efficient synthesis of cycloalkyl-fused naphthalenes through the [4 + 2]-cycloaddtion/decarboxylative aromatization of alkyne-tethered aryne insertion adducts. (bvsalud.org)
  • For the synthesis of monoareno pentalenes, a carbopalladation cascade reaction between alkynes and gem-dibromoolefins was applied. (researchgate.net)
  • The reaction proceeds via a cascade of four subsequent pericyclic reactions (Scheme 3). (wikipedia.org)
  • The reaction of 1-alkynes with Cy 2 NH and paraformaldehyde mediated by CuI (0.5 equiv) in refluxing dioxane produces terminal allenes in much higher yields than previously reported protocols and many functional groups such as mesylate, hydroxyl group, ether, amide, etc. are tolerated. (organic-chemistry.org)
  • alkyne-modified resins was accomplished by reaction of functional azides (octyl azide (1), (azidomethyl)benzene (2), 1-(6-azidohexyl) thymine (3), and 4-azido-N-(2,2,6,6-tetramethylpiperidin-4-yl)benzamide (4)) with Cu(I)Br and DIPEA as a base. (limkinase-signal.com)
  • The zinc enolate thus formed readily undergoes β-fragmentation unless it is trapped by electrophiles in situ. (journaltocs.ac.uk)
  • Lithium alkoxides of β-silylallylic alcohols underwent the Peterson elimination in DMF to give allenes. (organic-chemistry.org)
  • In order to apply PCR to the study of RNA, the RNA sample must first undergo the process of reverse transcription to generate cDNA, using the enzyme reverse transcriptase. (stratech.co.uk)
  • Alkynes - the group of unsaturated hydrocarbons with a triple Carbon-Carbon bond having the general formula C(n)H(2n-2). (carwashloansinfo.com)
  • The dienylketene then undergoes a six-electron electrocyclization to give a hexadienone intermediate which rapidly tautomerizes to yield a highly substituted phenol or naphthol structures. (wikipedia.org)
  • These rearrangements are performed in the presence of unsaturated compounds which undergo [2+2] cycloadditions with the in situ generated ketenes. (wikipedia.org)
  • Relative to other techniques for measuring mRNA, such as Northern blot analysis, RNAse protection assays, or in situ hybridization, RT-PCR is significantly more robust at detecting the RNA transcript of any gene regardless of its relative abundance. (stratech.co.uk)
  • This is a [2+1] cycloaddition of a carbene to an alkyne or alkene (more specifically in the Dӧtz reaction a carbene coordinated to a metal carbonyl group) to produce substituted aromatic phenols. (wikipedia.org)
  • A cyclic (alkyl)(amino)carbene ligand that contains a phosphino anchor enables the hydrogenation of alkynes in a trans -addition manner, selectively forming E -olefins. (nature.com)
  • These intermediates can then undergo an unprecedented iodine/gold exchange. (lookchem.com)
  • These rearrangements are performed in the presence of unsaturated compounds which undergo [2+2] cycloadditions with the in situ generated ketenes. (wikipedia.org)
  • N -Sulfonyl- and N -acylpyrroles were synthesized via olefin ring-closing metathesis of diallylamines followed by in situ oxidative aromatization in the presence of the ruthenium Grubbs catalyst and a suitable copper catalyst. (organic-chemistry.org)
  • In this work, we describe progress made in addressing the key stereochemical challenges in using two ligands in control of the selectivity in E - and Z -olefin formation by the hydrogenation of alkynes with molecular hydrogen (Fig. 1b ). (nature.com)
  • Pd-based Lindlar catalyst has been commonly used in industry for alkyne semihydrogenation in the selective production of Z-olefins 7 . (nature.com)
  • In this review, we collect the most recent contributions in which gold(I)- and/or gold(III)-catalysts mediate intramolecular (cyclo)isomerization transformations of unsaturated species, which commonly feature allene or alkyne motifs, and organize them depending on the substrate and the reaction type. (frontiersin.org)
  • Nevertheless, gold complexes are usually poorly-reactive in their precatalytic state and they need prior transformation in-situ , most commonly through the abstraction of one ligand, generally a chloride group. (frontiersin.org)
  • When ketenes are formed in the presence of alkynes they proceed through pericyclic reactions to generate a substituted aromatic ring (Scheme 2). (wikipedia.org)
  • The reaction proceeds via a cascade of four subsequent pericyclic reactions (Scheme 3). (wikipedia.org)
  • Upon addition of the alkyne a [2+2] cycloaddition occurs. (wikipedia.org)
  • Fig. 1: Controlling the stereochemistry in alkyne hydrogenation for highly selective formation of E - and Z -olefins. (nature.com)
  • The π-coordination of gold to the alkyne group of an ynamide substrate 6 promotes the formation of an electrophilic keteniminium ion 7 susceptible to a nucleophilic attack. (frontiersin.org)