title: Diastereoselectively switchable asymmetric haloaminocyclization for the synthesis of cyclic sulfamates.
abstract: An asymmetric synthesis of cyclic sulfamates by catalytic haloaminocyclization of primary sulfamate ester derivatives is described. The remarkable reversal of diastereoselectivity was found to be dependent on the halogen source and the chiral catalyst. By using privileged complexes of N,N'-dioxides with Sc(OTf)3 or Lu(OTf)3 as the catalyst, a variety of enantioenriched syn- and anti-cyclic sulfamates or related trans-aziridines could be obtained in 92-99 % ee and up to 97 % yield.
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064 (China).
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Cai
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zhou
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Liu
authors.forename: Jiannan
authors.initials: J
authors.lastname: Zhao
authors.forename: Lili
authors.initials: L
authors.lastname: Lin
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Feng
keywords: N,N′-dioxides; asymmetric catalysis; cyclic sulfamates; diastereoselectivity; haloaminocyclization; vicinal haloamines