Synthesis of Lactams by Isomerization of Oxindoles Substituted at C-3 by an ω-Amino Chain.

Oxindoles substituted at N-1 by electron-withdrawing groups and at C-3 by ω-amino chains of various lengths undergo mild and easy isomerization to new 5- to 12-membered lactams in good yields (30–96%). As efficient asymmetric syntheses of diversely 3,3-disubstituted oxindoles are currently developed, this isomerization provides a new and valuable access to medium-sized lactams α-substituted with a quaternary asymmetric carbon bearing a 2-aminophenyl residue.