Detailed 31 P{ 1 H} NMR spectroscopic investigations provided eeper insight into the complex, multi-step mechanisms involved in the recently reported photocatalytic arylation of white phosphorus (P 4 ). Specifically,t hese studies have identified anumber of previously unrecognized side products, which arise from an unexpected non-innocent behavior of the commonly employed terminal reductant Et 3 N. The different rate of formation of these products explains discrepancies in the performance of the two most effective catalysts, [Ir(dtbbpy)(ppy) 2 ][PF 6 ]( dtbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine) and 3DPAFIPN.I nspired by the observation of PH 3 as am inor intermediate,w eh ave developed the first catalytic procedure for the arylation of this key industrial compound. Similar to P 4 arylation, this method affords valuable triarylphosphines or tetraarylphosphonium salts depending on the steric profile of the aryl substituents.

Asymmetrically substituted tertiary phosphines and quaternary phosphonium salts are used extensively in applications throughout industry and academia. Despite their significance, classical methods to synthesize such compoundso ften demande ither harsh reaction conditions, prefunctionalization of startingm aterials, highly sensitive organometallic reagents, or expensive transition-metal catalysts. Mild, practical methodst husr emain elusive, despite being of great current interest. Herein, we describe av isible-light-drivenm ethod to form these products from secondary and primary phosphines. Using an inexpensive organic photocatalyst and blue-light irradiation, arylphosphines can be both alkylated anda rylatedu sing commercially available organohalides.I na ddition, the sameo rganocatalyst can be used to transform white phosphorus(P 4)d irectly into symmetrical aryl phosphines and phosphonium salts in as ingle reaction step, whichh as previously only been possibleu sing precious metalc atalysis.

Detailed 31 P{ 1 H} NMR spectroscopic investigations provided eeper insight into the complex, multi-step mechanisms involved in the recently reported photocatalytic arylation of white phosphorus (P 4 ). Specifically,t hese studies have identified anumber of previously unrecognized side products, which arise from an unexpected non-innocent behavior of the commonly employed terminal reductant Et 3 N. The different rate of formation of these products explains discrepancies in the performance of the two most effective catalysts, [Ir(dtbbpy)(ppy) 2 ][PF 6 ]( dtbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine) and 3DPAFIPN.I nspired by the observation of PH 3 as am inor intermediate,w eh ave developed the first catalytic procedure for the arylation of this key industrial compound. Similar to P 4 arylation, this method affords valuable triarylphosphines or tetraarylphosphonium salts depending on the steric profile of the aryl substituents.