Synthesis of cyclic carbonates from diols and CO2 catalyzed by carbenes

Abstract

The synthesis of cyclic carbonates from epoxides and CO₂ is a well-established reaction, whereas the synthesis of cyclic carbonates from diols and CO₂ is considerably more challenging, and few efficient catalysts are available. Here, we describe heterocyclic carbene catalysts, including one derived from a cheap and efficient thiazolium salt, for this latter reaction. The reaction proceeds at atmospheric pressure in the presence of an alkyl halide and Cs₂CO₃. Reaction mechanisms for the transformations involved are also proposed.