Biaryl Cross-Coupling Reactions Controlled by Fluoride Ion and Bulky Monodentate Ligands

摘要

The transition metal-catalyzed cross-coupling reaction is a powerful tool for selective synthesis of unsymmetrical biaryls. Among widely studied and utilized aryl metal reagents, such as aryl magnesium, zinc, copper, tin, silicon, aluminum, lithium, and boron compounds, aryl magnesium reagents are the most economical and versatile in terms of the practicality of biaryl synthesis. There have been, however, only a few industrial applications of unsymmetrical biaryl synthesis due to considerable formation of the byproduct symmetrical biaryls via the undesired homo-coupling reactions. Herein, we report simple and highly selective biaryl couplings based on iron, cobalt, and nickel-catalysts by the aid of a rather unconventional ligand combination; a fluoride anion and a bulky monodentate ligand.