Carbon−Phosphorus Coupling from C^N Cyclometalated Au(III) Complexes

With the aim of exploiting new organometallic species for cross-coupling reactions, we report here on the Au ^III-mediated C _aryl−P bond formation occurring upon reaction of C^N cyclometalated Au ^III complexes with phosphines. The [Au(C^N)Cl ₂] complex 1 featuring the bidentate 2-benzoylpyridine (C ^CON) scaffold was found to react with PTA (1,3,5-triaza-7-phosphaadamantane) under mild conditions, including in water, to afford the corresponding phosphonium 5 through C−P reductive elimination. A mechanism is proposed for the title reaction based on in situ ³¹P{ ¹H} NMR and HR-ESI-MS analyses combined with DFT calculations. The C−P coupling has been generalized to other C^N cyclometalated Au ^III complexes and other tertiary phosphines. Overall, this work provides new insights into the reactivity of cyclometalated Au ^III compounds and establishes initial structure–activity relationships to develop Au ^III-mediated C−P cross-coupling reactions.