- Palladium-catalyzed methylation of terminal alkynes
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In this communication, a palladium-catalyzed procedure for the methylation of terminal alkynes has been developed. With N,N,N-trimethylbenzenaminium trifluoromethanesulfonate as the methyl source, various desired products were obtained in moderate to good yields. Both aromatic and aliphatic alkynes are applicable.
- Wang, Wei-Feng,Wu, Xiao-Feng
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- Alkali metal-hydroxide-catalyzed C(sp)-H Bond silylation
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Disclosed is a mild, scalable, and chemoselective catalytic cross-dehydrogenative C-H bond functionalization protocol for the construction of C(sp)-Si bonds in a single step. The scope of the alkyne and hydrosilane partners is substantial, providing an entry point into various organosilane building blocks and additionally enabling the discovery of a number of novel synthetic strategies. Remarkably, the optimal catalysts are NaOH and KOH.
- Toutov, Anton A.,Betz, Kerry N.,Schuman, David P.,Liu, Wen-Bo,Fedorov, Alexey,Stoltz, Brian M.,Grubbs, Robert H.
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supporting information
p. 1668 - 1674
(2017/02/10)
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- BASE-CATALYZED SILYLATION OF TERMINAL ALKYNE C-H BONDS
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The present invention is directed to a mild, efficient, and general direct C(sp)-H bond silylation. Various embodiments includes methods, each method comprising or consisting essentially of contacting at least one organic substrate comprising a terminal a
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Paragraph 0157; 0158
(2016/05/02)
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- Mild and phosphine-free iron-catalyzed cross-coupling of nonactivated secondary alkyl halides with alkynyl grignard reagents
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A simple protocol for iron-catalyzed cross-coupling of nonactivated secondary alkyl bromides and iodides with alkynyl Grignard reagents at room temperature has been developed. A wide range of secondary alkyl halides and terminal alkynes are tolerated to a
- Cheung, Chi Wai,Ren, Peng,Hu, Xile
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supporting information
p. 2566 - 2569
(2014/05/20)
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- Gold-catalyzed highly regioselective oxidation of C-C triple bonds without acid additives: Propargyl moieties as masked α,β-unsaturated carbonyls
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Gold-catalyzed intermolecular oxidations of internal alkynes have been achieved with high regioselectivities using 8-alkylquinoline N-oxides as oxidants and in the absence of acid additives. Synthetically versatile α,β-unsaturated carbonyls are obtained in good to excellent yields and with excellent E-selectivities. A range of functional groups such as THP, MOMO, N3, OTBS, and N-Boc are tolerated. This reaction allows α,β-unsaturated carbonyls to be masked as propargyl moieties, thus offering a practical solution to compatibility issues with these functional groups likely encountered in syntheses of complex structures.
- Lu, Biao,Li, Chaoqun,Zhang, Liming
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supporting information; experimental part
p. 14070 - 14072
(2011/01/04)
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- Kinetic resolution of 1,2-diols through highly site- and enantioselective catalytic silylation
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(Chemical Equation Presented) Resolved to silylate: A chiral silylation catalyst is used for kinetic resolution of three classes of acyclic 1,2-diols. The catalyst differentiates, with excellent precision, between the two hydroxy groups of a substrate. The majority of the diols, obtained in high enantiomeric purity, cannot be accessed with similar stereochemical purity through catalytic asymmetric dihydroxylation.
- Zhao, Yu,Mitra, Aurpon W.,Hoveyda, Amir H.,Snapper, Marc L.
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p. 8471 - 8474
(2008/09/18)
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- Decarboxylative elimination of enol triflates as a general synthesis of acetylenes.
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The enol trifluoromethanesulfonates 4, 8, 12, 17 and 20 of tert-butyl beta-ketodiesters and beta-ketoesters can be hydrolysed to the corresponding carboxylic acids by dissolution in trifluoroacetic acid. The dicarboxylic acids undergo mild decarboxylative elimination to give the acetylenic acids 4 and 9 in aqueous sodium bicarbonate solution at room temperature. Similarly, the monocarboxylic acids give the terminal and mid-chain acetylenes 13, 18, 21, and 24 by refluxing in acetone with potassium carbonate. One of the substituents on the acetylenes can be methyl, primary alkyl, secondary alkyl or ethynyl, and the other can be a carboxylic acid, hydrogen or primary alkyl, but the enol trifluoromethanesulfonates could not be prepared when one of the substituents was tert-butyl, nor when both substituents on the precursor to the acetylene were secondary alkyl.
- Fleming, Ian,Ramarao, Chandrashekar
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p. 1504 - 1510
(2007/10/03)
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- Decarboxylative elimination of enol triflates as a general synthesis of acetylenes
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Decarboxylative elimination of a range of enol triflates of β-keto esters gives acetylenes.
- Fleming, Ian,Ramarao, Chandrashekar
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p. 1113 - 1114
(2007/10/03)
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