Copper porphyrin catalyzed esterification of C(sp 3 )–H via a cross-dehydrogenative coupling reaction

The crystal structure of 5,10,15,20-tetra(ethoxycarbonyl)porphyrin copper( ii ) showed that its central copper has a six-coordinate structure. An efficient copper porphyrin-catalyzed cross-dehydrogenative coupling (CDC) esterification reaction between C(sp 3 )–H and carboxylic acids using di- tert -butyl peroxide (DTBP) as an oxidant was established. The kinetic isotope effect (KIE) indicated that C(sp 3 )–H bond cleavage was the rate-determining step of this CDC reaction.