Application of a 1-(2-aryl)dicyclohexylphosphonium tetrafluoroborate ligand in the conjugated synthesis of heteroaryl biphenyls

Abstract

The development of novel indenyl ligands for carbon–carbon coupling reactions is a longstanding challenge, especially those used to obtain more efficient products, reduce the catalytic dosage, and provide greener reaction pathways. In this paper, we describe the synthesis of a class of readily accessible, highly tunable, and user-friendly non-chiral indenyl ligands featuring a dicyclohexyl (2-(2,6-dimethoxyphenyl)-4,7-dimethyl-1H-inden-1-yl) phosphonium skeleton utilizing a divergent synthesis strategy. The resulting indenyl-Pd catalysts were successfully applied toward the carbon–carbon coupling reaction of (hetero)aryl halogenated derivatives with heterarylboronic acid to smoothly prepare a variety of biphenyl products.