Tetramethylammonium salts: highly selective catalysts for the preparation of gem-dichlorocyclopropanes from electrophilic alkenes and chloroform under phase- …

M Fedorynski, W Ziolkowska…

Index: Fedorynski, Michal; Ziolkowska, Wanda; Jonczyk, Andrzej Journal of Organic Chemistry, 1993 , vol. 58, # 22 p. 6120 - 6121

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Citation Number: 25

Abstract

Haloform treated with concentrated aqueous sodium hydroxide and a quaternary ammonium salt (Q+ X-) as a catalyst (phase-transfer catalysis, PTCl) generates trihalomethyl anion which further splits into dihalocarbene. Depending on the kind of the alkene present in the system, each of these particles may be trapped. When simple, nucleophilic alkenes smoothly add dihalocarbene; those substituted by an electron-withdrawing group, EWG ( ...