Wolf, Zeitler and co-workers developed a mild, versatile and visible-light-mediated approach for the selective formation of a broad range of asymmetrical aryl/aryl and aryl/alkyl tertiary phosphines and quaternary phosphonium salts, combining stable, commercially available organic halides with phenyl-substituted primary and secondary phosphines, as depicted in Scheme 1. Interestingly, the optimal photocatalytic results were obtained using blue-light irradiation, DIPEA, and the organic photocatalyst 3DPAFIPN (2), affording the desired products in good-to-excellent yields (50 examples, yields up to 94%). Additionally, the same photocatalytic methodology was applied to transform P₄ directly into symmetrical aryl phosphines and phosphonium salts.¹ 

Dilman and co-workers reported a novel synthetic methodology for the selective iododifluoromethylation of alkenes employing an iododifluoromethylphosphonium salt, unactivated alkenes and a photocatalyst, PXX, active under blue-light irradiation. As depicted in Scheme 2, the mechanistic proposal includes an initial photoactivation of the carbon-iodine bond, generating a (phosphonio)difluoromethyl radical cation, which attacks the double bond with subsequent quenching by the iodine. The iododifluoromethylation products were then obtained upon hydrolysis of the phosphonium salt intermediates.²