Abstract
Binuclear complexes [{(DMOX)CuCl)(2)(mu-Cl)(2)] (1), mononuclear complexes [(DMOX)CuBr2] (2) (DMOX = 4,5-dihydro-2-(4,5-dihydro-4,4-dimethyloxazol-2-yl)-4,4-dimethyloxazole) and the pybox Cu(II) complex [(Dm-Pybox)CuBr2] (3) (Dm-Pybox = 2,6-bis[4', 4'-dimethyloxazolin-2'-yl] pyridine) were obtained by reactions of CuX2 (X = Cl, Br) with DMOX and Dm-Pybox ligands, respectively. The molecular structures of 1, 2 and 3 have been determined by single-crystal X-ray diffraction analyses. The complexes 2 and 3 are efficient in catalyzing alpha-amination of ketones and esters through alpha-bromo carbonyl intermediate. The procedures are environmentally benign methods using molecular oxygen as an oxidant with water as the only byproduct.