Asymmetric synthesis of new chiral N-sulfinyl 2,2-disubstituted aziridines by Grignard additions across alpha-chloro N-sulfinyl ketimines.
Reaction of chiral alpha-chloro N-tert-butanesulfinyl ketimines with Grignard reagents afforded new chiral N-sulfinyl 2,2-disubstituted aziridines in good to excellent diastereomeric ratio (dr up to 98 : 2). The 1,2,2-trisubstituted aziridines were isolated in high overall yield (51-85%) and with excellent enantiomeric excess (>98% ee). The stereoselectivity obtained in the Grignard addition is rationalized by the coordinating ability of the alpha-chloro atom resulting in the opposite stereochemical outcome as observed for nonfunctionalized N-sulfinyl ketimines.
Colpaert
Filip
F
Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Mangelinckx
Sven
S
Leemans
Erika
E
Denolf
Bram
B
De Kimpe
Norbert
N
D001388:Aziridines / Q000138:chemical synthesis* / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D013237:Stereoisomerism
D001388:Aziridines; D007097:Imines; D009570:Nitriles; C542835:ketimine; D002713:Chlorine; C033132:aziridine; D009584:Nitrogen