Polipirazolilborato complejos de cobre (I) como catalizadores en reacciones de transformación de olefinas en ciclopropanos, aziridinas y epóxidos

Abstract

1. Synthesis of the catalyst precursors. The low-temperature reaction of CuI and the potassium salt of the Bp ligand, in acetonitrile (eq 1), leads to the isolation of a white solid of analytical composition BpCu (1). CuI + KBp ? BpCu + KCI (1) The reaction of 1 with one molar equiv of Bioy, dppe or PCy3 affords the complexes of general composition BpCuL (L = bipy,2; dppe, 3; PCy3, 4), as depicted in eq 2. BpCu + L ? BpCuL (2) L = bipy,2; dppe, 3; PCy 3, 4 When pyridine or triphenylphosphine are employed, two equiv are required to obtain the complexes BpCu + 2L ? BpCuL (3) L = py,5; PPh 3, 6 2. Olefin Cyclopropanation reaction catalyzed by compelxes 1-6 under homogeneous conditions. Complexes 1-6 have been employed as the catalyst precursor in the reaction of ethyldiazoacetate with several olefins in order to test their catalytic capabilities in the general cyclopropanation reaction.The results shown in Table 1 are in accord with the existence of a moderate catalytic activity of such those complexes for this transformation.