Selective synthesis of nitrogen bi-heteroarenes by a hydrogen transfer-mediated direct α,β-coupling reaction

Org Biomol Chem. 2017 Aug 7;15(29):6093-6097. doi: 10.1039/c7ob01434a. Epub 2017 Jul 12.

Abstract

By an external hydrogen transfer-mediated activation mode, we herein demonstrate a new palladium-catalyzed direct α,β-coupling of different types of N-heteroarenes. Such a selective coupling reaction proceeds with the advantages of operational simplicity, high atom-economical efficiency, and use of safe and abundant i-propanol as the activating agent, offering a practical way to access nitrogen bi-heteroarenes. Preliminary exploration has revealed that the obtained bis-1,10-phenanthroline 2qq' as a ligand is capable of improving a copper catalyst for C-C bond formation. The work reported in this paper has built an important basis for the creation of extended π-conjugated systems that are of high significance in biological, medicinal, materials and synthetic organic chemistry as well as catalysis.