Expanding the chemistry of thiolyl derivatives of phospholes

Abstract

Bis[(3,4-dimethylphosphole) Pentacarbonyltungsten] sulfide, 3 , the precursor of P-S-P linked phosphinidene, 2, undergoes a [2+2] cycloaddition, followed by a Cope rearrangement to form the [4+4] cycloaddition adduct, 5. The mechanism has been proven by the isolation and characterization of the [2+2] cycloaddition adduct, 4. From optimization of compound 5, it was found to work best with visible light irradiation using dichloromethane as the solvent.