Novel 1D CuI coordination polymer using phosphorus-nitrogen ligands , active in aerobic oxidation of cyclohexene

This work reports the synthesis and characterization of a novel copper(I) coordination polymer, the first one containing a phosphorus-nitrogen ligand, [Cu(& kappa;2-P,N-(diphenylphospino)pyrimidine-2-amine)2Cl]n. This coordination polymer acts as catalyst under homogeneous conditions using molecular oxygen as oxidant. (5 bar and 40 to 120 degrees C). The catalyst shows high conversion for several substrate/catalyst ratio values (400/1 to 12800/1), and the reaction takes place in the absence of additional solvent with the advantages that this entails. The reported system shows 80% conversion for the cyclohexene oxidation in only 15 min of reaction, using a high substrate/catalyst ratio of 3200/1 with turnover number of 10240 h-1. The catalyst only looses 13% of conversion after 4 cycles. The study suggests a radical mechanism assisted by the catalyst that favors the formation of two major products, 2-cyclohexen-1-one and 2-cyclohexen-1-ol.