title: Asymmetric synthesis of γ-chloro-α,β-diamino- and β,γ-aziridino-α-aminoacylpyrrolidines and -piperidines via stereoselective Mannich-type additions of N-(diphenylmethylene)glycinamides across α-chloro-N-sulfinylimines.
abstract: The asymmetric synthesis of new chiral γ-chloro-α,β-diaminocarboxylamide derivatives by highly diastereoselective Mannich-type reactions of N-(diphenylmethylene)glycinamides across chiral α-chloro-N-p-toluenesulfinylaldimines was developed. The resulting (S(S),2S,3S)-γ-chloro-α,β-diaminocarboxylamides were formed with the opposite enantiotopic face selectivity as compared to the (S(S),2R,3R)-γ-chloro-α,β-diaminocarboxyl esters obtained via Mannich-type addition of analogous N-(diphenylmethylene)glycine esters across a chiral α-chloro-N-p-toluenesulfinylaldimine. Selective deprotection under different acidic reaction conditions and ring closure of the γ-chloro-α,β-diaminocarboxylamides was optimized, which resulted in N(α)-deprotected syn-γ-chloro-α,β-diaminocarboxylamides, N-sulfinyl-β,γ-aziridino-α-aminocarboxylamide derivatives, a trans-imidazolidine, and an N(α),N(β)-deprotected syn-γ-chloro-α,β-diaminocarboxylamide.
authors.affiliation: Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium, Tel: +32 (0)9 264 59 51.
authors.forename: Gert
authors.initials: G
authors.lastname: Callebaut
authors.forename: Sven
authors.initials: S
authors.lastname: Mangelinckx
authors.forename: Pieter
authors.initials: P
authors.lastname: Van der Veken
authors.forename: Karl W
authors.initials: KW
authors.lastname: Törnroos
authors.forename: Koen
authors.initials: K
authors.lastname: Augustyns
authors.forename: Norbert
authors.initials: N
authors.lastname: De Kimpe