Encapsulation of chiral CoII(R,R)(salen) in mesocellular foam as an efficient heterogeneous catalyst for asymmetric electrocarboxylation of 1-phenylethyl chloride with CO2

Abstract

The electrocarboxylation of organic molecules with CO₂ allows the synthesis of important carboxylic acids under mild conditions. The introduction of chiral sources enables the catalytic asymmetric synthesis of chiral carboxylic acids using CO₂ as a C1 source, which has important application prospects. In this work, we have successfully prepared chiral immobilized electrode materials by encapsulating chiral Co^II(R,R)(salen) (Co^IIL) complexes in the pores of mesocellular foam (MCF) materials using the strategy of silanization to reduce the pore size. The prepared Co^IIL@MCF composites exhibited good electrocatalytic performance in the asymmetric electrocarboxylation of 1-phenylethyl chloride with CO₂, leading to the synthesis of chiral 2-phenylpropionic acid with an enantiomeric excess value of 71% and a yield of 49%. The encapsulated Co^IIL@MCF composites can significantly reduce the amount of chiral Co^IIL complexes used. Moreover, they are stable, easy to separate, and have excellent reusability.