Palladium-Catalyzed Aerobic Oxidative Coupling of Allylic Alcohols with Anilines in the Synthesis of Nitrogen Heterocycles.

Abstract

We report herein an unprecedented and expedient Pd-catalyzed oxidative coupling of allyl alcohols with anilines to afford β-amino ketones which are converted into substituted quinolines in a one-pot fashion. The exclusive preference for N-alkylation over N-allylation makes this approach unique when compared to those reported in literature. Detailed mechanistic investigations reveal that the conjugate addition pathway was the predominant one over the allylic amination pathway. The notable aspects of the present approach are the use of readily available, bench-stable allyl alcohols and molecular oxygen as the terminal oxidant, in the process dispensing the need for unstable and costly enones. Further, we explored the synthetic utility of β-amino ketones through an intramolecular α-arylation methodology and a one-pot domino annulation, thereby providing rapid access to indolines and quinolines.