Pd-catalyzed CO-free double carbonylation for the synthesis of 1,4-ketoesters with Mo(CO)6 as the carbonyl source.

An unprecedented Pd-catalyzed CO-free double carbonylation using Mo(CO)6 as a safe carbonyl source for the efficient synthesis of 1,4-ketoesters in an atom- and step-economic manner has been developed. The current method features operational safety, a wide substrate range, good functional group compatibility and easy scale-up. The application of carbonylation using a safe carbonyl source for the synthesis of biologically and synthetically useful carbonyl-containing molecules is underway in our lab.