Mutual Placement of Isocyanide and Phosphine Ligands in Platinum(II) Complexes [PtHal 2 L 1 L 2 ] (Hal = Cl, Br, I; L 1 ,L 2 = CNCy, PPh 3 ) Leads to Highly-Efficient Photocatalysts for Hydrosilylation of Alkynes.

A series of platinum complexes featuring phosphine and isocyanide ligands [PtX 2 (PPh 3 )(CNCy)] (X = Cl, Br, and I) as well as their parent phosphine [PtX 2 (PPh 3 ) 2 ] and isocyanide [PtX 2 (CNCy) 2 ] analogues have been prepared and evaluated as catalysts for the photocatalytic hydrosilylation of alkynes. Under violet light irradiation (λ max = 400 nm), phosphine-isocyanides complexes [PtX 2 (PPh 3 )(CNCy)] gave high yields of silylated products (product yield up to 99%, TONs up to 1.98 × 10 3 ). The blue light irradiation (λ max = 450 nm) was more suitable for the parent phosphine complexes [PtX 2 (PPh 3 ) 2 ], which showed comparable efficiency (product yield up to 99%, TON up to 1.98 × 10 3 ), while isocyanide complexes [PtX 2 (CNCy) 2 ] were not active.