Mn-promoted aerobic oxidative C-C bond cleavage of aldehydes with dioxygen activation: a simple synthetic approach to formamides.

A novel Mn-promoted aerobic oxidative C-C bond cleavage of aldehydes with dioxygen activation has been developed. The usage of molecular oxygen (1 atm) as oxidant, reactant, and an initiator to trigger this transformation makes this transformation very green and practical. A plausible radical process is proposed on the basis of mechanistic studies. Furthermore, this method provides a practical, neutral, and mild synthetic approach to formamides, which are important units in biologically active molecules.