title: Highly diastereoselective[3+2] cycloadditions between nonracemic p-tolysulfinimines and iminoesters: an efficient entry to enantiopure imidazolidines and vicinal diaminoalcohols.
abstract: A new procedure for the asymmetric synthesis of imidazolidines and vicinal diamines is reported. The 1,3-dipolar cycloaddition between nonracemic p-tolylsulfinimines and azomethine ylides generated in situ from alpha-iminoesters and LDA produces N-sulfinylimidazolidines with a high degree of stereocontrol. In contrast, the presence of Lewis acids promotes formation of the cycloadducts through a 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
authors.affiliation: Instituto de Química Orgánica, CSIC, Madrid, Spain. iqov379@iqog.csic.es
authors.forename: Alma
authors.initials: A
authors.lastname: Viso
authors.forename: Roberto
authors.initials: R
authors.lastname: Férnandez de la Pradilla
authors.forename: Ana
authors.initials: A
authors.lastname: Garciá
authors.forename: Carlos
authors.initials: C
authors.lastname: Guerro-Strachan
authors.forename: Marta
authors.initials: M
authors.lastname: Alonso
authors.forename: Mariola
authors.initials: M
authors.lastname: Tortosa
authors.forename: Aida
authors.initials: A
authors.lastname: Flores
authors.forename: Martín
authors.initials: M
authors.lastname: Martínez-Ripoll
authors.forename: Isabel
authors.initials: I
authors.lastname: Fonseca
authors.forename: Isabelle
authors.initials: I
authors.lastname: André
authors.forename: Ana
authors.initials: A
authors.lastname: Rodríguez