Synthesis of Bio‐Based Cyclic Carbonates Using a Bio‐Based Hydrogen Bond Donor: Application of Ascorbic Acid to the Cycloaddition of CO₂ to Oleochemicals

Abstract

Oleochemicals such as functionalized fatty acid esters and vegetable oils are classes of renewably sourced compounds that are increasingly attracting attention in sustainable chemistry as replacement for fossil-fuel based chemicals. The possibility of coupling CO 2 with epoxidized fatty acids esters (EFAEs) and epoxidized vegetable oils (EVOs) to afford compounds that are attractive as additives or chemical intermediates in the synthesis of non-isocyanate polyhydroxyurethanes (NIPU) can conjugate highly soughtafter CO 2 valorization with the exploitation of bio-based substrates. In this context, there have been very few attempts to employ organocatalytic hydrogen bond donors (HBDs) in the cycloaddition reaction of CO 2 to EFAEs and EVOs and no studies focusing on bio-based and readily available HBDs. In this work we show that ascorbic acid is an efficient HBD for the cycloaddition of CO 2 to EFAEs and EVOs under mild reaction conditions of temperature (80-100°C) and pressure (5-10 bar) that could be applied to several kinds of substrates (monounsaturated EFAEs, polyunsaturated EFAEs and EVOs). In all cases, the formed by-products (ketones, allylic alcohols, cyclic ethers etc.) were identified and the reaction conditions were tuned in order to obtain the target carbonates, generally, in high yields and selectivity.[a] W. Natongchai, S. Pornpraprom,

Recent progress in the catalytic transformation of carbon dioxide into biosourced organic carbonates

“…Among the catalysts, simple and readily available L-ascorbic acid 14/TBAC allowed the synthesis of the cis-iCFA1 from cis-iEFA1 with high diastereoselectivity (cis : trans = 85 : 15). 231 The system 14/TBAC showed (expectedly) lower substrate conversion than 14/TBAB and 14/TBAI but higher chemoselectivity towards cis-iCFA1 (>99%), whereas in the other two cases a significant amount of the side products were formed (entry 3). When 13/TBAI or 14/TBAI were selected as catalysts, trans-iCFA1 was observed as the main carbonate product (entries 1 and 3), whereas iCFA1 was preferentially formed when utilizing bifunctional catalyst 15 regardless of the nature of the halide (entry 4) though with the lowest stereocontrol towards cis-iCFA1 in the presence of iodide.…”

Efficient Synthesis of Cyclic Carbonates from Unsaturated Acids and Carbon Dioxide and their Application in the Synthesis of Biobased Polyurethanes

“…Although phenolic phosphonium salts catalyzed this transformation without needing a co‐catalyst, they required longer reaction times [12d] . Finally, the recently reported ascorbic acid/TBAC catalyst system catalyzed the preparation of the cyclic carbonate product in an excellent yield (85 %) at lower reaction pressure, though it required 48 hours and higher reaction temperature (Table 4, entry 10) [12f] …”

“…However, the use of an iodide anion as nucleophile source produced the trans isomer as the major product (Table 3, entry 3). It is worth mentioning that allyl alcohol by‐product 8 was obtained as a side product when PPNCl was used as co‐catalyst (Figure S53; Table 3, entries 4, 6 and 8) due to the rearrangement of the epoxide functionality [11d,12e,f] …”

Dataset for the synthesis and application of single-component heterogeneous catalysts based on zinc and tin for the cycloaddition of pure, diluted, and impure CO2 to epoxides under mild conditions

“…63 generally show the formation of signals relative to the cyclic carbonate products in the 4-5 ppm region and the disappearance of the signals relative to the epoxide substrates in the 2-3 ppm region [7] , [8] , [9] . These data are useful to estimate the conversion of epoxides and to calculate conversion values based on the integration of corresponding signals of products and epoxides [10] , [11] , [12] . These data generally confirm the complete or nearly complete conversion of epoxide substrates and the absence of evident reaction by-products and the reproducible application of the catalysts…”