α-L-diarylprolinol as the organocatalyst and K2CO3 as the additive has been accomplished. The spirocyclopropanes were isolated in high yield and up to 85 % ee. Notably, the asymmetric one-pot sequential approach to spirocyclopropanes proved to be a feasible process.
Reactions of electron-deficient alkenes with dibromomethylene compounds activated by cyanide and ester groups were promoted by LiI to afford the corresponding cyclopropanes in high yields.
Electrocatalytic multicomponent cyclization of aromatic aldehydes, malononitrile, and malonates into 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylates
作者:A. N. Vereshchagin、M. N. Elinson、A. S. Dorofeev、G. I. Nikishin
DOI:10.1007/s11172-009-0113-4
日期:2009.5
Electrolysis of aromatic aldehydes, malononitrile and malonates in methanol in an undivided cell in the presence of double-mediator system NaBr-NaOAc afforded 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylates in 40–60% yields.
Electrocatalytic transformation of dialkyl malonates and arylidene- or alkylidenemalononitriles into dialkyl esters of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acids
作者:M. N. Elinson、S. K. Feducovich、T. A. Zaimovskaya、A. N. Vereshchagin、S. V. Gorbunov、G. I. Nikishin
DOI:10.1007/s11172-006-0008-6
日期:2005.7
Electrolysis of alcoholic solutions of dialkyl malonates and arylidene- or alkylidenemalononitriles in the presence of NaBr in an undivided cell gave dialkylesters of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acids in 60–90% yields.
We report herein a visiblelightinduced generation of a carbanion via double-SET and its application in cyclopropanation of alkenes. This new synthetic approach to form cyclopropane derivatives was conducted under mild conditions, using sunlight in open air, showing the features such as environmental benignness and an easy to handle procedure.