A Divergent Strategy for Site‐Selective Radical Disulfuration of Carboxylic Acids with Trisulfide‐1,1‐Dioxides

Abstract

The direct conversion of carboxylica cids into disulfides is described. The approach employs oxidative photocatalysis for base-promoted decarboxylation of the substrate,w hich yields an alkylr adical that reacts with at risulfide dioxide through homolytic substitution. The trisulfide dioxides are easily prepared by an ewly described approach.1 8 8,2 8 8,a nd 38 8 carboxylic acids with varied substitution are good substrates,i ncluding amino acids and substrates with highly activated CÀHbonds.Trisulfide dioxides are also used to achieve the g-C(sp 3 )ÀHd isulfuration of amides through aradical relaysequence.Inboth reactions,the sulfonyl radical that results from substitution propagates the reaction. Factors governing the selectivity of substitution at S2 versus S3 of the trisulfide dioxides have been explored.