Electrocarboxylation of Spiropyran Switches through Carbon‐Bromide Bond Cleavage Reaction

Abstract

This manuscript deals with carbon capture and utilization to synthetize high-added chemicals using CO 2 as a C1-organic building block for CÀ C bond formation. The study focuses on the electrocarboxylation of 1,3,3-trimethylindolino-6'-bromobenzopyrylospiran switch (Br-BIPS). Prior to the electrocarboxylation process, the electrochemical reduction mechanism of Br-BIPS and CO 2 is disclosed in polar aprotic solvents using two different cathodes (glassy carbon and silver) under nitrogen atmosphere. Once the role of the cathode in the reduction carbon-bromide bond cleavage is understood, carboxylated spiropyran derivatives can be synthesized in moderate yields and conversion rates through an electrocarboxylation process using CO 2 silver cathode and polar aprotic solvents. The "green" efficient route described in the current work would open a new sustainable strategy for designing and building "smart" surfaces with switchable physical properties.

Toward green syntheses of carboxylates: Considerations of mechanisms and reactions at the electrodes for electrocarboxylation of organohalides and alkenes

“…More complex aryl halide, bromospipyran, can also be used to performed electrocarboxylation. A glassy carbon or a Ag electrode was used to performed the reaction with CH3I as an additive for easy product isolation, yielding carboxylated spiropyran in moderate yield [37].…”