Asymmetric Radical and Anionic Cyclizations of Axially Chiral Carbamates

Standard Boc, Alloc, and Cbz derivatives of N-2,4-dimethyl-6-iodophenyl-N-allyl anilines are axially chiral and can be readily resolved into atropisomers whose racemization barriers exceed 30 kcal/mol. The resolved axially chiral carbamates undergo radical and anionic cyclizations with high levels of chirality transfer from the N−Ar axis to the new stereocenter in the substituted dihydroindole products. The carbamate groups of the products are readily removed.