Cycloaddition of 1,4-Dimethyl-2,3-dimethylenehexahydropyrazine to Electron Deficient Alkenes
作者:Carina Sofia Kniep、Roland Boese、Reiner Sustmann
DOI:10.1016/s0040-4020(00)00340-9
日期:2000.6
The mechanism of cycloaddition of 1,4-dimethyl-2,3-dimethylenehexahydropyrazine to moderately and highly electrophilic alkenes is probed by stereochemical studies. Retention of configuration for the E/Z-isomeric alkenes fumaro- and maleonitrile and loss of stereospecificity for dimethyl dicyanofumarate and dimethyl dicyanomaleate show that the mechanism of cycloaddition (concerted or stepwise) depends
立体化学研究了1,4-二甲基-2,3-二亚甲基六氢吡嗪向中度和高度亲电性烯烃环加成的机理。配置的保持对é / Ž -isomeric烯烃fumaro-和马来腈和立体定向性的损失为二甲基dicyanofumarate和二甲dicyanomaleate表明,环加成(协调或逐步地)的机制取决于反应伙伴亲核和亲电性质之间的差距。1,4-二甲基-2,3-二甲基亚乙基六氢吡嗪的行为遵循其他氨基取代的二烯的行为。