Organic Base-Catalyzed C-S Bond Construction from CO2: A New Route for the Synthesis of Benzothiazolones

The synthesis of organosulfur compounds via the construction of C-S bonds using CO2 as a C1 resource is very interesting. Herein, a novel method of synthesizing benzothiazolones via the cyclocarbonylation of 2-aminothiophenols with CO2 was developed. A series of organic bases was investigated for the catalysis of cyclocarbonylation, and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) displayed the best catalytic activity. Then, various reaction parameters such as CO2 pressure, temperature, amount of catalyst, and reaction time for the catalytic performance were studied. Finally, a series of benzothiazolones was synthesized under the optimal reaction conditions, and a possible catalytic mechanism was also proposed.