Highly Stereo-Controlled Synthesis of Fatty Acid-Derived Cyclic Carbonates by Using Iron(II) Complex and Nucleophilic Halide

A catalytic system comprising an iron(II) complex and a nucleophilic halide for the preparation of a series of stereo-bio-derived cyclic carbonates was developed. The protocol allows for the coupling of various cis-fatty acid-derived epoxides. For example, cis-epoxy substrates can be reacted with CO2 to selectively yield either the cis- or trans-cyclic carbonates by adjusting the nucleophilic halide. These reactions are highly stereoselective and have excellent yields even under mild reaction conditions. The stereochemical divergence in the fatty acid-derived products strongly depends on the leaving ability of the halide anion in the cocatalyst.