[CuII-Hfur-imidazole] compounds as precursors of efficient hydrogenation and reductive alkylation catalysts in flow systems

The reaction of copper(II) acetate with furoic acids (2Hfur / 3Hfur) and imidazole (Im) in methanol resulted in mononuclear complexes [Cu(fur)2(Im)2(H2O)]& sdot;L (fur- = 2fur- (1, 2), 3fur- (3); L = MeCN (1)) whose structures were determined by direct single crystal X-ray analysis. It was found for the first time that copper nanoparticles immobilized on the surface of gamma-Al2O3 obtained by chemical reduction of 1, 2 and 3 (pre-deposited on the surface from solution) with sodium tetrahydroborate show high selectivity of mono-and dihydrogenation of tricyclo [5.2.1.02,6]deca-3,8-diene (dicyclopentadiene, DCPD). The catalytic activity tests show a high selectivity (97 %) of the catalyst obtained from an ethanolic solution of complex 1 in the reaction of partial hydrogenation to DHDCPD under continuous process conditions even at high conversion values (up to 96 %) and with an excess of hydrogen, whereas the catalyst obtained from an aqueous solution of complex 1 showed 98 % total hydroge-nation product (THDCPD) selectivity. The catalysts based on all the complexes 1-3 were successfully used in reactions of nitrobenzene (NB) reduction to aniline (AN) and in the reductive alkylation of nitrobenzene with isobutanol (i-BAN) 100 % yields of aniline and N-isobutylaniline were obtained at LHSV 0.16 h-1.