Cooperative Multifunctional Organocatalysts for Ambient Conversion of Carbon Dioxide into Cyclic Carbonates

Abstract

A series of pincer-type compounds possessing an N-heterocyclic carbene precursor and a carboxyl group as proton transfer agent were synthesized and used as organocatalysts for the cycloaddition of epoxides with CO 2 . In this context, we have demonstrated the high activity of these one-component organocatalysts in the CO 2 transformation to cyclic carbonates under ambient conditions (room temperature, 1 bar of CO 2 ). The catalytic potential of these multifunctional organocatalysts on challenging internal epoxides is particularly deserving of mention because organocatalysts that are able to mediate the cycloaddition reaction of internal epoxides with CO 2 under mild conditions remain scarce. The intramolecular synergistic activation mechanism was elucidated by control experiments and DFT calculations.

Recent Advances in the Chemical Fixation of Carbon Dioxide: A Green Route to Carbonylated Heterocycle Synthesis

“…However, styrene oxide, as well as other epoxides giving stable carbocations, often gave partial racemization, which is accounted for a partial Sn1 mechanism. It should be noted that the scorpionate catalyst (entry 43) was rationally designed by authors on the basis of the mechanism and combining experimental and computational efforts [84].…”

Imidazolium‐Functionalized Ionic Hypercrosslinked Porous Polymers for Efficient Synthesis of Cyclic Carbonates from Simulated Flue Gas

“…ILs and their derivatives have favorable CO 2 ‐philic natures, and their anions are the active nucleophiles for the ring opening of epoxides, normally the rate‐determining step in the CO 2 cycloaddition . As a result, a great number of IL‐derived materials have been established as adsorbents and catalysts for CO 2 capture and fixation .…”

Cycloaddition of atmospheric CO2to epoxides under solvent-free conditions: a straightforward route to carbonates by green chemistry metrics

“…3). 46 The results indicated that the catalyst 19e containing phenolic hydroxyl group was catalytically more active than other catalysts. Thus, in the presence of 4 mol% of organocatalyst 19e under ambient conditions a range of substituted epoxides 20 underwent coupling with CO 2 provided the corresponding carbonates 21 in good to excellent yields (Scheme 12).…”