Alkyne reaction

Because of the slightly acidic nature of the sp C-H bonds, the reaction of metal acetylides with various electrophiles is one of the most general strategies in organic transformations.1 Traditionally, such reactions are carried out by using alkali metal acetylides which are air and water sensitive. On the other hand, there is much interest in developing transition-metal catalyzed terminal alkyne reactions involving soft and more stable C-M bonds as reaction intermediates, because many such reactions can tolerate water. 

In addition to the reactions discussed above, there are still other alkyne reactions carried out in aqueous media. Examples include the Pseudomonas cepacia lipase-catalyzed hydrolysis of propargylic acetate in an acetone-water solvent system,137 the ruthenium-catalyzed cycloisomerization-oxidation of propargyl alcohols in DMF-water,138 an intramolecular allylindination of terminal alkyne in THF-water,139 and alkyne polymerization catalyzed by late-transition metals.140... 

Addition of 2 mol equivalents of T " to alkynes gave bis-perchlorates 40 [R = H, Me, Ph R = R = MeO (geometry not established)], which were explosive upon heating. The alkyne reactions were much slower than those with alkenes, and no reaction at all occurred with ethyl propiolate, from which it was concluded that all these reactions have the character of electrophilic addition to the unsaturated unit (79JOC915). 

Bis(trifluoromethyl) peroxycarbonate, 705 Bis(trifluoromethyl) peroxydicarbonate, 705 Bis(trifluoromethyl) trioxide IR spectrum, 740 O NMR spectroscopy, 182 Bis(trifluoromethyl) tiioxydicarbonate, 740 Bis(trimethylsilyl) monoperoxysulfate Baeyer-Vilhger oxidation, 785 catalytic epoxidation, 791-2 Bis(trimethylsilyl) peroxide (BTSP) alcohol oxidation, 787-90 alkyne reactions, 800 aromatic compounds, 794-5 Baeyer-Vilhger ketone oxidation, 784-7 demethylation, 798... 

In short, while the overall features of OH-alkyne reactions are understood, more research needs to be done, especially on the alkynes larger than acetylene. 

In the case of internal symmetric or terminal alkynes, reaction takes place according to Markovnikov selectivity, unlike the problem of regioselectivity that appears when internal asymmetric alkynes are used. Unfortunately, at that time only the gold(I) compound K[Au(CN)2] was tested, a compound that is now known not to be effective as a catalyst, unlike many other gold(I) compounds. 

From an atom economy perspective, He and Shi achieved efficient solventless hydroarylation of alkynes. Reaction took place efficiently under air atmosphere at ambient temperature and different functional groups could be tolerated. The catalytic system employed was AuCl3/AgTfO (1 3) and both inter-molecular and intra-molec-ular processes were described [128]. 

Although the details of the mechanisms of these alkyne reactions are not known, it is likely that the ability of 1-alkynes to form carbon-metal bonds with metals such as copper is a key factor. 

Cadiot-Chodkiewicz reaction, 11, 19 Hiyama reaction, 11, 23 Kumada-Tamao-Corriu reaction, 11, 20 Migita-Kosugi-Stille reaction, 11, 12 Negishi coupling, 11, 27 overview, 11, 1-37 Suzuki-Miyaura reaction, 11, 2 terminal alkyne reactions, 11, 15 Cu-mediated reactions acetylenes, 10, 551 dienes, 10, 552... 

Cross-coupling reactions 5-alkenylboron boron compounds, 9, 208 with alkenylpalladium(II) complexes, 8, 280 5-alkylboron boron, 9, 206 in alkyne C-H activations, 10, 157 5-alkynylboron compounds, 9, 212 5-allylboron compounds, 9, 212 allystannanes, 3, 840 for aryl and alkenyl ethers via copper catalysts, 10, 650 via palladium catalysts, 10, 654 5-arylboron boron compounds, 9, 208 with bis(alkoxide)titanium alkyne complexes, 4, 276 carbonyls and imines, 11, 66 in catalytic C-F activation, 1, 737, 1, 748 for C-C bond formation Cadiot-Chodkiewicz reaction, 11, 19 Hiyama reaction, 11, 23 Kumada-Tamao-Corriu reaction, 11, 20 via Migita-Kosugi-Stille reaction, 11, 12 Negishi coupling, 11, 27 overview, 11, 1-37 via Suzuki-Miyaura reaction, 11, 2 terminal alkyne reactions, 11, 15 for C-H activation, 10, 116-117 for C-N bonds via amination, 10, 706 diborons, 9, 167... 

Hexa(—)menthyldistannane, preparation, 3, 856 Hexamethylbenzenes, with titanium, 4, 246 Hexamethylcyclotrisiloxane, in polymerization, 3, 654 Hexamethyldigermane, terminal alkyne reactions, 10, 747 1,1,2,2,3,3-Hexamethylindane, metallation, 9, 15—16 Hexanuclear arenes, in hexaruthenium carbido clusters,... 

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