The Synthesis and Catalytic Activity of New Mixed NHC-Phosphite Nickel(0) Complexes

• Published in: Organometallics Vol. 39; no. 1; pp. 105 - 115
• Main Authors: Duczynski, Jeremy, Sobolev, Alexandre N, Moggach, Stephen A, Dorta, Reto, Stewart, Scott G
• Format: Journal Article
• Language: English
• Published: American Chemical Society 13.01.2020
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/acs.organomet.9b00672

Herein we describe the synthesis and isolation of the first low-valent NHC-phosphite nickel complexes of general formula Ni­(NHC)­[P­(OAr)3]2. These three-coordinate Ni(0) compounds were fully characterized, including by X-ray crystallography that highlighted their trigonal planar geometry. The representative complex Ni­(IMes)­[P­(OPh)3]2 was used to show that a phosphite ligand is readily substituted in the presence of an aldehyde or nitrile. These stoichiometric studies then led to an investigation of their catalytic properties in the Suzuki–Miyaura cross-coupling reactions between aryl tosylates and aryl boronic acids, a first for such a NHC-Ni catalyst. Finally, mechanistic investigations led to the isolation of a well-defined oxidative addition product.