α-Branched amines by catalytic 1,1-addition of C–H bonds and aminating agents to terminal alkenes

Abstract

α-Branched amines are present in hundreds of pharmaceutical agents and clinical candidates and are important targets for synthesis. Here, we show the convergent synthesis of α-branched amines from three readily accessible starting materials: aromatic C–H bond substrates, terminal alkenes and aminating agents. This reaction proceeds by an intermolecular formation of C–C and C–N bonds at the sp3 carbon branch site through an uncommon 1,1-alkene addition pathway. The reaction is carried out under mild conditions and has high functional group compatibility. Ethylene and propylene feedstock chemicals are effective alkene inputs, with ethylene in particular providing for the one-step synthesis of α-methyl branched amines, a motif prevalent in drug structures. The reaction is scalable and 1% loading of an air-stable dimeric rhodium precatalyst is effective for several different types of products. The use of chiral catalysts also enables the asymmetric synthesis of α-branched amines.