Silver-Catalyzed C(sp³)-H Sulfonylation for the Synthesis of Benzyl Sulfones Using Toluene Derivatives and α-Amino Acid Sulfonamides

We describe a simple and practical protocol for the synthesis of benzyl sulfones using readily available toluene derivatives and α-amino acid sulfonamides. The reaction proceeds to afford a broad range of benzyl sulfones in moderate to high yields under silver catalysis. The mechanism possibly involves a Minisci-type formation of α-aminoalkyl radical, homolytic cleavage of a N-S bond to generate a sulfonyl radical, and coupling of sulfonyl radical with a benzyl radical formed via hydrogen abstraction by sulfate anion radical. The practicality of the present reaction is demonstrated by a gram-scale synthesis and one-step synthesis of anticancer-active compound. The mechanism studies are conducted using radical scavengers and deuterated toluene.