Asymmetric synthesis of cyclopropylamines starting from N-sulfinyl alpha-chloro ketimines.
Treatment of novel chiral N-sulfinyl alpha-chloro ketimines with Grignard reagents resulted in the synthesis of chiral N-(1-substituted cyclopropyl)-tert-butanesulfinamides in acceptable to good yields and diastereoselectivity via 1,3-dehydrohalogenation and subsequent addition of the Grignard reagent to the intermediate cyclopropylideneamine. Only in the case of allylmagnesium chloride did the reaction lead to aziridines in high yield. Further deprotection toward N-unprotected 1-substituted cyclopropylamines was established, and the absolute configuration was determined. [reaction: see text].
Denolf
Bram
B
Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Mangelinckx
Sven
S
Törnroos
Karl W
KW
De Kimpe
Norbert
N
D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D007202:Indicators and Reagents; D015394:Molecular Structure; D013237:Stereoisomerism
D003521:Cyclopropanes; D007097:Imines; D007202:Indicators and Reagents; C067351:cyclopropylamine