Abstract
Amines are prominent in natural products, pharmaceutical agents, and agrochemicals. Moreover, they are synthetically valuable building blocks for the construction of complex organic molecules and functional materials. However, amines, especially aliphatic and aromatic amines with free N-H, are prone to coordinate with transition-metal and deactivating the catalyst, posing a tremendous challenge to the application of Lewis basic amines in the amination of olefins. Herein we present the first case of oxidative amination of simple olefins with various Lewis basic amines. The combination of a palladium catalyst, 2,6-dimethyl-1,4-benzoquinone (2,6-DMBQ), and a phosphorous ligand leads to the efficient synthesis of alkyl and aryl allylamines. A series of allylamines are obtained with good yields and excellent regio- and stereoselectivities. Intramolecular amination to synthesize tetrahydropyrrole and piperidine derivatives was also realized. Mechanistic investigations reveal that the reaction undergoes allylic C(sp3)-H activation and subsequent functionalization.
Palladium-catalyzed selective oxidative amination of olefins with Lewis basic amines