Carboranycarboxylate Complexes as Efficient Catalysts in Epoxidation Reactions

Abstract

This work presents the first examples of carboranylcarboxylate complexes as precatalysts in epoxidation reactions with the use of peracetic acid as the oxidant. The manganese [Mn(μ-H2O)(1-CH3-2-CO2-1,2-closo-C2B10H10)2]n·(H2O)n (1), [Mn2(1-CH3-2-CO2-1,2-closo-C2B10H10)4(2,2'-bpy)2] (2, bpy = bipyridine), [Mn(1-CH3-2-CO2-1,2-closo-C2B10H10)2(bpm)]n (3, bpm = bipyrimidine), and [Mn(1-CH3-2-CO2-1,2-closo-C2B10H10)2(2,2'-bpy)2] (4) complexes and the cobalt [Co2(μ-H2O)(1-CH3-2-CO2-1,2-closo-C2B10H10)4(thf)4] (6) complex, all containing the carboranylcarboxylic 1-CH3-2-CO2H-1,2-closo-C2B10H10 (LH) ligand, together with Mn3(OAc)6(2,2'-bpy)2 (5) displayed good performance with high conversions and selectivity values in short reaction times, in most cases. This work highlights that the coordination of the carboranylcarboxylic ligand to the metal ions is crucial to the performance of the complexes as catalysts