Palladium-catalyzedcarbonylative cross coupling reaction of organofluorosilanes with organic halides was achieved in the presence of fluoride ion and an atmospheric pressure of carbon monoxide. Alkenyl- or arylfluorosilanes effectively underwent this reaction with alkenyl or aryl iodides in moderate to good yields. Thus, highly functionalized ketones are readily available without protection of reactive
Synthesis of Enantioenriched (<i>Z</i>)-Disubstituted Allylic Alcohols via Ru-Catalyzed Selective Dehydrogenation
作者:Dongxu He、Donghao Wang、Chen Xu、Xiangyou Xing
DOI:10.1021/acs.joc.3c00986
日期:2023.7.21
A highly efficient kinetic resolution of allylicalcohols with Z/E mixtures was achieved via Ru-catalyzed selective dehydrogenation. Not only allylicalcohols were obtained with pure Z-geometry, but the corresponding selectivity factors rank among the few highest for kinetic resolution reported in the literature.
Phase-transfer catalysed asymmetric epoxidation of enones using N-anthracenylmethyl-substituted Cinchona alkaloids
作者:B. Lygo、P.G. Wainwright
DOI:10.1016/s0040-4020(99)00205-7
日期:1999.5
A study into the enantioselective epoxidation of alpha, beta-unsaturated ketones utilising Cinchona alkaloid-derived quaternary ammonium phase-transfer catalysts bearing an N-anthracenylmethyl function is presented. It has been found that the O-benzyl derivatives of these catalysts in conjunction with sodium hypochlorite give high enantio and diastereoselectivities in the epoxidation of a range of substates (RCH)-C-1=CHCOR2, where R-1=alkyl or aryl and R-2=aryl. In the cases where R-2=alkyl high enantioselectivity has also been observed however the rate of reaction is substantially reduced. Application of this process to the enantioselective synthesis of a range of trans-alpha, beta-epoxy ketones (e.e. 90%) is presented. (C) 1999 Elsevier Science Ltd. All rights reserved.