Dihalogenation ofgem-Aryl-Disubstituted Methylenecyclopropanes by DEAD, DIAD/TiX4 or Free Halogen
作者:Li-Xiong Shao、Lin-Jing Zhao、Min Shi
DOI:10.1002/ejoc.200400388
日期:2004.12
gem-aryl-disubstituted methylenecyclopropanes with TiX4/diethyl azodicarboxylate and TiX4/diisopropyl azodicarboxylate in 1,2-dichloroethane gave the dihalogenated ring-opened product, 2,4-dihalobut-1-ene, in moderate-to-excellent yields under mild conditions. On the basis of the proposed Orton-type mechanism, we found that this reaction can also be carried out with free halogens such as bromine or iodine
偕芳基二取代亚甲基环丙烷与 TiX4/偶氮二甲酸二乙酯和 TiX4/偶氮二甲酸二异丙酯在 1,2-二氯乙烷中反应得到二卤化开环产物 2,4-二卤代丁-1-烯,产率中等至极好在温和的条件下。根据提出的 Orton 型机理,我们发现该反应也可以与游离卤素(如溴或碘)一起进行,从而以良好的收率得到相同的产物。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)