syn-1,2-Amino Alcohols via Diastereoselective Allylic C-H Amination

摘要

This method represents the first general and stereoselective Pd(Ⅱ)-catalyzed allylic C-H animation reaction. The good levels of diastereoselectivity and functional group tolerance demonstrated for this method enable the synthesis of densely functionalized anti-oxazolidinone products that can be rapidly transformed into useful syn-1,2-amino alcohols. Mechanistic studies support a Pd(Ⅱ)/bis-sulfoxide mediated C-H cleavage to form a π-allylPd intermediate followed by a Pd(Ⅱ) counterion-mediated deprotonation of the nitrogen nucleophile to achieve functionalization. The latter aspect of this mechanism may provide a general approach for achieving activation of weak nucleophiles without attenuating the reactivity of an electrophilic metal catalyst. Current studies are focused on further exploration of the scope and mechanism of this reaction.