Synthesis of the Indene, THF, and Pyrrolidine Skeletons by Lewis Acid Mediated Cycloaddition of Methylenecyclopropanes with Aldehydes,N-Tosyl Aldimines, and Acetals
作者:Li-Xiong Shao、Bo Xu、Jin-Wen Huang、Min Shi
DOI:10.1002/chem.200500447
日期:2006.1
Methylenecyclopropanes (MCPs 1) react with aldehydes, N-tosyl aldimines, and acetals to give the corresponding indene, THF, and pyrrolidine cycloaddition products in the presence of BF3 x OEt2 under mild reaction conditions. Some special transformations of MCPs 1 with aldehydes have been reported in this paper. A plausible reaction mechanism has been discussed, which is based on a deuterium-labeling
亚甲基环丙烷(MCP 1)在温和的反应条件下,在BF3 x OEt2存在的情况下,与醛,N-甲苯磺酰胺和缩醛反应,生成相应的茚,THF和吡咯烷环加成产物。本文报道了醛类化合物MCPs 1的一些特殊转化。基于氘标记实验和Prins型反应机理,讨论了可能的反应机理。
Ring-Expansion of MCPs in the Presence of DIAD or DEAD and Lewis Acids
作者:Li-Xiong Shao、Min Shi
DOI:10.1002/ejoc.200300515
日期:2004.1
Treatment of methylenecyclopropanes (MCPs) with DIAD or DEAD in MeCN under mild conditions in the presence of Lewisacid Zr(OTf)(4) gave the cyclobutanone ring-expansion products in good to high yields based on the employed DIAD or DEAD. From a deuterium labeling experiment, the oxygen atom is derived from ambient water. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
A novel ring-opening reaction of methylenecyclopropanes with aromatic amines catalyzed by Lewis acids
作者:Min Shi、Yu Chen、Bo Xu、Jie Tang
DOI:10.1016/s0040-4039(02)01984-6
日期:2002.11
Methylenecyclopropanes (MCPs) can react with aromatic amines to give the corresponding homoallylic amines in good to high yields in the presence of Lewisacids. The substituents on the benzene ring of the MCPs or the aromatic amines can affect significantly the reaction rate.
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 freehalogens such as bromine or iodine
Reactions ofgem-Aryl-Disubstituted Methylenecyclopropanes with Diaryl Diselenide in the Presence of Iodosobenzene Diacetate
作者:Min Shi、Bao-Yu Wang、Jia Li
DOI:10.1002/ejoc.200400644
日期:2005.2
The reaction of gem-aryl-disubstituted methylenecyclopropanes 1 with diaryldiselenide produced the corresponding ring-opened products 1,2-bis(arylselanyl)-3,3-diarylcyclobut-1-ene 4 in the presence of iodosobenzenediacetate in moderate-to-good yields under mild conditions. The further transformation of 4 in the presence of MCPBA has also been examined. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451