DIINSERTION OF FLUORENYLIDENE INTO A SULFUR-SULFUR BOND OF DIARYL DISULFIDES

Upon irradiation (>340 nm) of a benzene solution of diazofluorene with di-p-tolyl-or di-p-anisyl disulfide, the corresponding 9,9'-bis(arylm ercapto)bifluorenyl was afforded in moderate to good yield accompanied by formation of 9,9'-bis(arylmercapto)fluorene. The major reaction pa thway is considered to be a disulfur ylide formation followed by two t imes of successive Stevens rearrangement or by concerted electron redi stribution via [2,3]sigmatropic rearrangement. (C) 1997 Elsevier Scien ce Ltd.