Reduction of CO2 with NaBH4/I2 for the Conversion of Thiophenols to Aryl Methyl Sulfides

We report a tandem reaction to realize reduction of carbon dioxide with thiophenols to generate aryl methyl sulfides under the NaBH4/I2 system with 18-crown-6 as the solvent. Thiophenols bearing electron-donating and electron-withdrawing groups are feasible in this reaction. Controlled experiment results indicate that 18-crown-6 plays a critical role in six-electron reduction of carbon dioxide.