Ligand-Accelerated Direct C-H Arylation of BINOL: A Rapid One-Step Synthesis of Racemic 3,3'-Diaryl BINOLs

Abstract

An ortho-selective rhodium-catalyzed direct C-H arylation of 1,1'-bi-2-naphthol (BINOL), to deliver the widely used but not easily available 3,3'-diaryl BINOL, has been developed. This highly efficient one-step synthetic approach is the shortest route to date and is greatly facilitated by the newly developed ligand system comprising tBu₂ PCl, Ph₂ -cod, and Cy₃ P⋅HBF₄ . In addition, the same procedure can facilitate the challenging syntheses of 3-bulkyaryl BINOLs in good to excellent yields.

Keywords: arylation; biaryls; cross-coupling; ligand design; rhodium.