Synthesis of five-, six-, and seven-membered ring lactams by Cp*Rh complex-catalyzed oxidative N-heterocyclization of amino alcohols

A new effective catalytic system consisting of [Cp*RhCl2](2)/K2CO3 (CP* = pentamethylcyclopentadienyl) for the lactamization of amino alcohols has been developed. As an example, the reaction of 3-(2-aminophenyl)-1-propanol in the presence of [Cp*RhCl2](2) (5.0% Rh) and K2CO3 (10%) in acetone gives 3,4-dihydro-2(1h)-quinolinone in an isolated yield of 80%. A variety of five-, six-, and seven-membered benzo-fused lactams are synthesized by this catalytic system.