Stereoselective synthesis of (Z)-trifluoromethyl enamines and their Lewis acid-mediated conversion into (E)-isomers
摘要:
(Z)-beta-Trifluoromethyl enamines were prepared in high yield stereoselectively by reaction of 2-bromo-3,3,3-trifluoropropene with N-alkyl toluenesulfonamides and potassium t-butoxide in one pot via Michael addition and elimination processes. The (Z)-beta-trifluoromethyl enamines could be converted to the corresponding thermodynamically stable (E)-isomers promoted by Lewis acid catalysts at room temperature or thermal isomerization. (C) 2002 Elsevier Science Ltd. All rights reserved.
Applications of 2-Chloro-3,3,3-trifluoroprop-1-ene (HCFO-1233xf): A Rapid Entry to Various β-Substituted-trifluoromethyl-ethenes
作者:Daniel Meyer、Myriem El Qacemi
DOI:10.1021/acs.orglett.0c00931
日期:2020.5.1
An efficient base-promoted reaction of O-, N-, and S-nucleophiles with 2-chloro-3,3,3-trifluoprop-1-ene (HCFO-1233xf) is described providing access to various β-substituted-trifluoromethyl-ethenes under mild reaction conditions. Mechanistic investigations shed some light on the regio-, chemo-, and stereoselectivities observed. The olefins prepared represent attractive intermediates in chemical discovery:
Stereoselective synthesis of (Z)-trifluoromethyl enamines and their Lewis acid-mediated conversion into (E)-isomers
作者:Biao Jiang、Fangjiang Zhang、Wennan Xiong
DOI:10.1016/s0040-4020(01)01157-7
日期:2002.1
(Z)-beta-Trifluoromethyl enamines were prepared in high yield stereoselectively by reaction of 2-bromo-3,3,3-trifluoropropene with N-alkyl toluenesulfonamides and potassium t-butoxide in one pot via Michael addition and elimination processes. The (Z)-beta-trifluoromethyl enamines could be converted to the corresponding thermodynamically stable (E)-isomers promoted by Lewis acid catalysts at room temperature or thermal isomerization. (C) 2002 Elsevier Science Ltd. All rights reserved.