CoAl metahydrotalcite-B efficiently catalyzes the aerobic oxidative cleavage of 1,2-diols without any additives

CoAl metahydrotalcite-B have been developed as a highly efficient heterogeneous catalyst for the aerobic oxidative cleavage of 1,2-diols using ethanol as the green solvent in the absence of any additives. This reusable catalyst can enable the transformation of various 1,2-diols selectively to the corresponding aldehydes or ketones under mild conditions. Among the samples obtained from CoAl hydrotalcite treated with different temperatures, CoAl metahydrotalcite-B phase forms for the Co2Al-LDO(250) sample, which contains abundance of basic site of Co-O2--Al and active Co3+ site on surface. The study on the structure-activity relationship indicated that strong surface basicity and Co3+ sites on surface should be responsible for the excellent catalytic activity. Mechanistic investigations revealed that the reaction proceeded via a monodentate, two-electron oxidative fragmentation process. The Co2Al-LDO(250) also exhibited good applicability in tandem reactions with a variety of nucleophiles.