Boosting the Catalytic Performance of Organic Salts for the Fast and Selective Synthesis of α-Alkylidene Cyclic Carbonates from Carbon Dioxide and Propargylic Alcohols

The synthesis of alpha-alkylidene cyclic carbonates (CCs) by the carboxylative coupling of CO2 with propargylic alcohols is receiving increasing interest but requires the use of catalysts that are most often added in large quantities and/or lack selectivity. Herein, we describe the fine-tuning of the structure of organocatalysts of the ammonium-type that enables us to identify the important structural parameters that dictate their catalytic performance. Tetrabutylammonium oxalate was revealed to be one of the most attractive organocatalysts with a remarkably fast, complete and selective production of CCs at a low catalyst loading (2.5 mol%) under solvent-free conditions. This study opens new avenues for the facile and selective synthesis of libraries of CCs from CO2 and propargylic alcohol by using simple organocatalysts.