Highly Reactive Palladium-Catalyzed and Acetonitrile-Mediated Three-Component Reactions for Arylsulfone Synthesis.

Arylsulfone groups play an important role in the synthesis of functionalized molecules. The acetonitrile-mediated three-component reactions for arylsulfone synthesis were developed in the presence of a 0.00025 mol % palladium catalyst. Arylboronic acids reacted with potassium metabisulfite (K 2 S 2 O 5 ) and benzyl bromide in the presence of LiF and a very low concentration of PdCl 2 in acetonitrile solvents to produce the corresponding benzyl arylsulfones in moderate to good yields. Various arylboronic acids reacted with K 2 S 2 O 5 and carbon electrophiles to produce the desired arylsulfones under the optimized conditions. It was proposed that acetonitrile accelerated the generation of aryl anion species from the reaction of arylboronic acids and LiF.