研究室工作进展 Jun 12th, 2012

 Pd-Catalyzed Intermolecular Domino Reaction of gem-Dibromoenynes with Anilines: A One-Pot Synthesis of Quinolines and Quinolinones

Tianhao Meng, Wen-Xiong Zhang, Hui-Jun Zhang, Yun Liang, and Zhenfeng Xi*

Synthesis 2012, Accepted.

The gem-dihaloolefins have become important and versatile building blocks in palladium catalyzed domino reactions leading to heterocyclic compounds. Our group has been interested in the preparation and synthetic applications of polyhalo conjugated compounds. In this paper we report an intermolecular amination between amines and gem-dibromoenynes efficiently yielding quinolines and quinolinones. Mechanistic investigation disclosed that a Pd-catalyzed domino process involving Pd-catalyzed amination of the alkenyl bromide/1,5-H transfer/annulation via 6-exo-dig electrophilic cyclization/Pd-catalyzed etherification took place, resulting in a domino formation of Csp2-Csp, Csp2-N and Csp2-O bonds. The quinoline unit is an important skeleton found in a variety of bioactive compounds. Synthesis of N-heterocycles via intermolecular amination between amines and gem-dihaloolefins is rare. This Pd-catalyzed intermolecular domino reaction between amines and gem-dibromoenynes provides an efficient alternative synthesis of quinolines and quinolinones.