Multifunctional PNN-NiII pincer catalyst for C–C and C–N bond formation via alkylation, cross-coupling, and hydroamination reactions

Abstract

Ligand {(o-PPh₂)C₆H₄C(O)N(H)CH₂(C₅H₄N)} (1) upon reaction with [NiCl₂(DME)] afforded [NiCl{(PNN)-κ³-P,N,N}] (2), while its oxide derivative {(o-(O)PPh₂)C₆H₄C(O)N(H)CH₂(C₅H₄N)} (3) yielded Ni^III pincer [{NiCl(μ-Cl)₂NiCl}{(P(O)NN)₂-κ³-O,N,N}] (4). Complex 2 catalyzes diverse transformations, including α-alkylation of ketones, N-alkylation of anilines, and Suzuki–Miyaura cross-coupling of aryl chlorides. Notably, complex 2 promotes the hydroamination of styrene to selectively afford the anti-Markovnikov product, acting as an efficient and versatile catalyst, operating under mild conditions at low loadings (0.5–1 mol%) and delivering high yields (80–99%).