Geminal Silicon/Zinc Reagent as an Equivalent of Difluoromethylene Bis-carbanion
作者:Mikhail D. Kosobokov、Vitalij V. Levin、Artem A. Zemtsov、Marina I. Struchkova、Alexander A. Korlyukov、Dmitry E. Arkhipov、Alexander D. Dilman
DOI:10.1021/ol5002297
日期:2014.3.7
A new difluorinated reagent, [difluoro(trimethylsilyl)methyl]zinc bromide, bearing C-Zn and C-Si bonds is described. The reagent is conveniently prepared by cobalt-catalyzed halogen/zinc exchange. It can be coupled with two different C-electrophiles in a stepwise manner (with allylic halides for C-Zn bond and aldehydes for C-Si bond) affording products containing a difluoromethylene fragment.
Nucleophilic difluoro(trimethylsilyl)methylation of arylidene Meldrum's acids
作者:Alexander D. Volodin、Artem A. Zemtsov、Vitalij V. Levin、Marina I. Struchkova、Alexander D. Dilman
DOI:10.1016/j.jfluchem.2015.05.009
日期:2015.8
A reaction of arylidene Meldrum's acids with difluoro(trimethylsilyl)methylzinc bromide in the presence of copper cyanide (10 mol%) is described. The primary addition products are hydrolized and decarboxylated followed by esterification of intermediate carboxylic acids affording beta-Me3SiCF2-substituted esters. Protodesilylation of Me3SiCF2-group can be performed under mild conditions affording CHF2-fragment. (C) 2015 Elsevier B.V. All rights reserved.