143767-04-8Relevant articles and documents
Reaction of Diphenyl Disulfide with Alkynes Promoted by Di-tert-butyl and Dibenzoyl Peroxides: a Useful Syntheic Route to 3- (and 2,3) Substituted Benzothiophenes
Benati, Luisa,Montevecchi, Pier Carlo,Spagnolo, Piero
, p. 1659 - 1664 (2007/10/02)
Thermal reactions of diphenyl disulfide 1 with phenylacetylenes 2a-e promoted by di-tert-butyl peroxide (TBP) at 110 or 150 deg C provides a useful synthetic route to the (2-substituted) 3-phenylbenzothiophenes 4a-e, which result from intramolecular cyclization of 1-phenyl-2-(phenylthio)vinyl radical intermediates 3a-e.Similar reactions of the disulfide 1 with tert-butyl- and trimethylsilylacetylenes 2f and 2g also provide the corresponding benzothiophenes 4f and 4g in satisfactory yields; low yields of the benzothiophene products 4h, i, however, are obtained with hex-1-yne 1h and hex-3-yne 1i.Evidence is presented that the thermal reaction of the disulfide 1 with the alkynes 2 at 100 deg C in the presence of dibenzoyl peroxide, while being of little use for the synthesis of benzothiophenes 4, generally leads to the 2-(phenylthio)vinyl benzoates 10; this is ascribed to initial addition of benzoyloxy radicals to alkyne triple bonds.
