Preparation and synthetic application of methyl β,β-difluoro-α-trimethylsilyloxyacrylate: a fluoride ion-promoted desilylative-defluorination route
摘要:
Catalytic amount of TBAT (0.2 mol %) promoted desilylation and subsequent defluorination of ketene silyl acetal of methyl O-trimethylsilyltrifluorolactate, affording methyl beta,beta-difluoro-alpha-trimethylsilyloxyacrylate in 95% yield of which reaction with electrophiles provided methyl beta-substituted-beta,beta-difluoropyruvate in good yields. (c) 2006 Elsevier Ltd. All rights reserved.
Synthesis and some heterocyclisation reactions of CF2H- and CF2Cl-substituted 1,1-dicyanoethylenes
作者:Alexander S Golubev、Pavel V Pasternak、Alexander F Shidlovskii、Ljudmila N Savelèva、Boris B Averkiev、Vladimir N Nesterov、Michail Yu Antipin、Alexander S Peregudov、Nikolai D Chkanikov
DOI:10.1016/s0022-1139(01)00559-0
日期:2002.3
New CF2X-analogues of 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene (1) (X=H, Cl) were synthesised by the condensation of polyfluoroketones with malononitrile followed by dehydration using thionyl chloride (or phosphorus pentoxide). The heterocyclisation reactions of new CF2X-analogues of 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene with amidines, 5-aminopyrazoles and 3-methyl-2-pyrazolin-5-ones were