Synthesis of Thieno[3,2-b]thiophene 1,1-Dioxide Derivatives

Significance

A one-pot synthesis of 3-aryl- or heteroaryl-substituted thieno[3,2-b]thiophene di­oxide derivatives is reported. The reaction proceeds via an interesting bimetallation of 3-(methylsulfonyl)thiophene in which the α-sulfonyl anion appears to act, in view of no observed metallation at the comparably acidic C-5 site, as a directed metallation group. Subsequent quench with aryl or heteroaryl esters leads to the products. The starting materials are prepared by treatment of commercially available 3-(methylthio)thiophene with MCPBA. The scope of the reaction was meagerly investigated.