93322-80-6Relevant academic research and scientific papers
Thiophenes as traps for benzyne. 3. Diaryl sulfides and the role of dipolar intermediates
Reinecke, Manfred G.,Del Mazza, Dario,Obeng, Marcus
, p. 70 - 74 (2007/10/03)
The reactions of seven thiophenes with benzyne generated from diphenyliodonium-2-carboxylate (DPIC) under a standard set of conditions led among other products to the formation of α- and β-naphthyl phenyl sulfides 2a and 2b from thiophene (1a) and of 2c: and 2d from 2-methylthiophene (1b). Dithienyl sulfides 4a-f were produced from the halothiophenes 1c-g. The structures of the naphthyl sulfides were proven by comparison with authentic samples of 2a-f, thus eliminating one of two possible mechanisms of formation. The remaining mechanism involves [4+2]-cycloaddition of benzyne to thiophene or to an S-phenylthiophenium ylide 10 to give the dipolar 2:1 benzyne/thiophene adduct 8 followed by ring-opening. Stevens-like rearrangements of 11, formed from 10 by proton transfer, may also explain the origin of arylated thiophenes such as 12 and 3 found in some reactions of benzynes with thiophene.
