Pd-catalyzed couplings of (α-fluoro)vinyl tris(trimethylsilyl)germanes
摘要:
The (alpha-fluoro)vinyl tris(trimethylsilyl)germanes undergo Pd-catalyzed cross-couplings with aryl and alkenyl halides upon oxidative treatment with hydrogen peroxide under basic aqueous conditions to give access to fluoroalkenes and fluorodienes with retention of stereochemistry. (c) 2005 Elsevier Ltd. All rights reserved.
Selective Monodefluorination and Wittig Functionalization of <i>gem</i>-Difluoromethyl Groups to Generate Monofluoroalkenes
作者:Dipendu Mandal、Richa Gupta、Rowan D. Young
DOI:10.1021/jacs.8b06770
日期:2018.8.29
Monodefluorination of gem-difluoromethyl groups is achieved using a frustrated Lewis pair (FLP) approach. Triarylphosphines and group 13 Lewis acids were surveyed as FLP components, with the combination of P(o-Tol)(3) and B(C6F5)(3) found to provide the best results, although the reaction is feasible with more economical components (PPh3 and BF3 center dot OEt2). The alpha-fluoroalkylphosphonium products arising from the reaction were of lower activity, in regard to further fluoride abstraction, as compared to difluoride starting materials, leading to highly selective monodefluorination. The activated substrates were subject to Wittig reaction protocols to generate a variety of monofluoroalkenes in moderate to high yields.
Pd-catalyzed couplings of (α-fluoro)vinyl tris(trimethylsilyl)germanes
作者:Zhizhong Wang、Aurelio Gonzalez、Stanislaw F. Wnuk
DOI:10.1016/j.tetlet.2005.06.023
日期:2005.8
The (alpha-fluoro)vinyl tris(trimethylsilyl)germanes undergo Pd-catalyzed cross-couplings with aryl and alkenyl halides upon oxidative treatment with hydrogen peroxide under basic aqueous conditions to give access to fluoroalkenes and fluorodienes with retention of stereochemistry. (c) 2005 Elsevier Ltd. All rights reserved.