Enantioselective and Regiodivergent Functionalization of N-Allylcarbamates by Mechanistically Divergent Multicatalysis.

A pair of mechanistically divergent multicatalytic reaction sequences has been developed consisting of nickel-catalyzed isomerization of N-allylcarbamates and subsequent phosphoric-acid-catalyzed enantioselective functionalization of the resulting intermediates. By appropriate selection of reaction partners, in situ generated imines and ene-carbamates are mechanistically partitioned to yield opposing functionalized products. Formal α-functionalization to give protected α-arylamines is achieved upon enantioselective Friedel-Crafts reaction with arene nucleophiles, whereas formal β-functionalization is achieved upon reaction with diarylimine electrophiles in an enantioselective Povarov-[4+2] cycloaddition.