Electrocarboxylation of spyropirian switches through carbon-bromide bond clevage reaction

This manuscript deals with carbon capture and utilization to synthetize high-added chemicals using CO ₂ as a C1-organic building block for C−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.