Highly Diastereoselective [3+2] Cycloadditions between Nonracemic p-Tolylsulfinimines and Iminoesters: An Efficient Entry to Enantiopure Imidazolidines and Vicinal Diaminoalcohols
作者:Alma Viso、Roberto Fernández de la Pradilla、Ana García、Carlos Guerrero-Strachan、Marta Alonso、Mariola Tortosa、Aida Flores、Martín Martínez-Ripoll、Isabel Fonseca、Isabelle André、Ana Rodríguez
DOI:10.1002/chem.200204674
日期:2003.6.16
highly diastereoselective process with opposite stereochemistry. Subsequent transformations of the imidazolidines including oxidative, reductive, and hydrolytic processes that provide easy access to vicinal diaminoalcohols have been explored. Among these, reductive cleavage of the aminal with LiAlH4 is an extremely efficient and general reaction for the synthesis of enantiopure N-sulfinyl-N'-benzyldiaminoalcohols
报道了咪唑烷和邻二胺的不对称合成的新方法。非外消旋对甲苯磺酰亚胺亚胺和由α-亚氨基酸酯和LDA原位产生的甲亚胺烷基化物之间的1,3-偶极环加成反应会产生具有高度立体控制的N-亚磺酰亚胺基咪唑烷。相反,路易斯酸的存在通过具有相反立体化学的高度非对映选择性过程促进环加合物的形成。已探索了咪唑烷的后续转化,包括氧化,还原和水解工艺,这些工艺可轻松获得邻位二氨基醇。在这些之中,用LiAlH4还原性缩醛是合成对映体纯的N-亚磺酰基-N'-苄基二氨基醇的极其有效且通用的反应