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The sulfinyl group in (R)-N-tert-butanesulfinyl aldimines provides efficient control of the stereoselectivity in the intermolecular reactions with alkyl radicals. The methodology is applicable to aryl, heteroaryl, benzyl, and alkynyl imines, even those containing CN, CO2Me, COR, and OH groups. The best results are attained with hindered radicals (tertiary and secondary ones) without C═N bond reduction. This reaction complements the well-established organometallic additions to N-sulfinyl aldimines to obtain enantiomerically pure functionalized α-branched primary amines.

The alkyl radical (R1) addition reaction to ortho-X-substituted N-(benzylidene)-2-methylpropane-2-sulfinamides (X = Br, CN, CO2Me, OH and OMe) is highly diastereoselective, regardless of the electronic properties of the X group and the size of R1. Easy removal of the sulfinyl group provides the title compounds in enantiomerically pure form. This two-step sequence has been successfully applied to the preparation of primary α-( tert-butyl)- ortho-hydroxy- and - ortho-methoxybenzylamines, as well as the 3-isopropyl-substituted isoindolin-1-one. [ABSTRACT FROM AUTHOR]