Catalytic synthesis of ethylene glycol from a C1 source

Abstract

Ethylene glycol is an industrially important compd. which is used in a variety of polymeric materials and antifreeze applications. Ethylene glycol is mass produced on a multibillion kilogram scale using ethylene as a C2 source. A potentially sustainable route to ethylene glycol based on synthesis from a C1 source is envisioned. Using formaldehyde as a methanol surrogate, we describe a one-pot two step procedure for ethylene glycol synthesis. In the first step, an N-heterocyclic carbene organocatalyst is used to condense two mols. of formaldehyde to form a C2 compd., glycoaldehdye. In the second step, a late transition metal organometallic catalyst is used to perform a transfer hydrogenation between methanol and glycoaldehdye, forming ethylene glycol and regeneratiing formaldehyde. Thus, two catalytic cycles were successfully combined for the synthesis of ethylene glycol from a C1 source in a conceptually new route. Optimization of the reaction parameters and precatalyst structures are reported.