Tetrabutyl ammonium salts: cheap catalysts for the facile and selective synthesis of a-alkylidene cyclic carbonates from CO2 and alkynol

n-tetrabutyl ammonium organic salts are used for the first time as catalysts for the coupling of CO2 with 2-methyl-3-butyn-2-ol to form α-methylene cyclic carbonate. The final yields could reach 98% in less than 10 hours at 353K and 3MPa under solvent free conditions. A particular synergistic effect between the cation and the anion of the organocatalyst is demonstrated through catalyst screening. Online kinetic studies by ATR-IR spectroscopy correlated to DFT calculations reveal a compelling evolution of the solvation of the catalyst during the reaction that provide an understanding of the underlying reason for the observed unique kinetics and selectivity. Such in-depth fundamental mechanistic and kinetic studies enable determining and comprehending the key parameters favouring the design of novel highly active and selective catalysts for the valorisation