Selective Synthesis of <i>ortho-</i>Substituted Diarylsulfones by Using NHC-Au Catalysts under Mild Conditions

Abstract

A single-step gold(I)-catalyzed chemoselective protocol to access ortho-substituted diarylsulfones has been established. Acenaphthoimidazolylidene gold complexes are effective catalysts for the arylsulfonylation of boronic acids by potassium metabisulfite (K₂S₂O₅) and diaryliodonium salts to access (poly-) ortho-substituted diarylsulfones even in gram scale. Unlike the transition metal-catalyzed two-component coupling systems, the sterically hindered aryl groups in diaryliodonium salts are preferentially transferred over less bulky ones to form synthetically difficult targets, including those of pharmaceutical importance.