Tris(pyrazolyl)borate rhodium complexes. Application for reductive amination and esterification of aldehydes in the presence of carbon monoxide

The halide complexes TpRhCl(2)(MeOH) and Tp(Me2)RhI(2)(CO) (Tp = hydrotris-(pyrazolyl)borate; Tp(Me2) = hydrotris-(3,5-dimethylpyrazolyl)borate) were synthesized by reactions of RhCl3 with K[Tp] in methanol and Tp(Me2)Rh(CO)(2) with iodine, respectively. Reactions of Tp(Me2) RhCl2(MeOH) and Tp(Me2)RhI(2)(CO) with 1,10-phenanthroline afford the phenanthroline derivatives [Tp(Me2)Rh(phen)X](+) (X = Cl, I). The structures of TpRhCl(2)(MeOH) and TpRhI(2)(CO) were determined by X-ray diffraction. Tris(pyrazolyl)borate rhodium complexes effectively catalyze the reductive amination and the reductive esterification of aldehydes in the presence of carbon monoxide. (C) 2020 Elsevier B.V. All rights reserved.