A new method for the preparation of alkynes from vinyl triflates
摘要:
Treatment of vinyl triflates with lithium diisopropylamide results in the selective formation of alkynes in moderate to high yields. (C) 1998 Elsevier Science Ltd. All rights reserved.
Palladium-Catalyzed Diorganozinc Conjugate Additions to Enones: Preparative and Computational Studies
作者:Paula Lorenzo、José M. Aurrecoechea、Angel R. de Lera、Rosana Álvarez
DOI:10.1002/ejoc.201201519
日期:2013.5
The Pd-catalyzed conjugateaddition of diorganozinc reagents to α,β-unsaturated carbonyl compounds has been applied to a variety of enone substrates, both cyclic and acyclic, encompassing various combinations of aryl and alkyl substitution, in combination with diorganozinc reagents incorporating alkyl (Me, linear and branched) or Ph groups. While both Pd0 and PdII complexes have been found to be competent
Ligand-Enabled γ-C(sp<sup>3</sup>)–H Activation of Ketones
作者:Ru-Yi Zhu、Zi-Qi Li、Han Seul Park、Chris H. Senanayake、Jin-Quan Yu
DOI:10.1021/jacs.8b01359
日期:2018.3.14
are identified to enable C(sp3)-H activation for the first time. A rare six-membered palladacycle intermediate is isolated and characterized to elucidate the reaction mechanism. Both (hetero)arylation and vinylation of γ-C(sp3)-H bonds are demonstrated. Sequential β- and γ-C(sp3)-H (hetero)arylation of muscone showcases the utility of this method for late-stagediversification. A convenient Mn(II)-catalyzed
Amino-sugar modular ligands—useful cores for the formation of asymmetric copper 1,4-addition catalysts
作者:Antonella De Roma、Francesco Ruffo、Simon Woodward
DOI:10.1039/b813137f
日期:——
Modular phosphine ligands, synthesised rapidly from commercial N-acetylglucosamine, are very effective in copper(I)-catalysed 1,4-additions of ZnR2 to linear aliphatic enones (87â95% ee).
The Michael-type reaction of copper-catalyzed trialkylaluminium reagents with α,β-unsaturated carbonylcompounds is a useful and simple procedure for the transfer of hydrocarbon substituents. The scope of this process and the effect of chlorotrimethylsilane as additive were investigated. Preparatively useful results were generally obtained for enones even with higher organoaluminium reagents, whereas
Copper-Catalysed Asymmetric Conjugate Addition of Organometallic Reagents to Linear Enones
作者:Simon M.W Bennett、Stephen M Brown、Anthony Cunningham、Michael R Dennis、James P Muxworthy、Michael A Oakley、Simon Woodward
DOI:10.1016/s0040-4020(00)00140-x
日期:2000.4
Methods for enantioselective 1,4-addition of main-group organometallics to linearenones are overviewed. Thiourethane and thioether 1,1′-binaphthyl-based ligands are effective for copper-catalysed 1,4-addition of ZnEt2 and AlR3 (R=Me, Et) to trans-alkyl-3-en-2-ones; enantioselectivities of up to 72% e.e. are attained. In comparison 1,4-addition of ZnEt2 to 2-cyclohexenone proceeds in up to 77% e.e