Simultaneous quantitative structure-activity relationship analysis of catalyst activity and selectivity in the direct oxidation of C―H bonds

The development of green, efficient, and stable organometallic catalysts for the selective direct oxidation of C―H bonds under mild reaction conditions represents a long-standing challenge for chemists. Can the catalytic activity and selectivity be improved simultaneously through modification of the catalyst structure? To address this question, three one-pot C―H oxidation reactions catalyzed by a series of structurally diverse metalloporphyrins were studied using mechanistically relevant molecular parameters derived mainly from density functional theory calculations. Particle swarm optimization (PSO) algorithm was performed to search for the best descriptor subsets to obtain simple quantitative structure-activity relationship models with high correlations. The reaction outcomes (transformation rates and selectivity) of the three reactions were modeled with six multivariate linear regression equations using a pool of 17 parameters representing charges, steric effects, and other parameters. These studies cast new light on the reaction mechanisms and the relationships among the molecular properties that influence the catalytic activity and selectivity of these species and guide the further development of more efficient and selective catalysts through careful design of the molecular structure.