Derivatization of castor oil based estolide esters: Preparation of epoxides and cyclic carbonates

Recent developments in organocatalysed transformations of epoxides and carbon dioxide into cyclic carbonates

“…Please do not adjust margins synthetic route towards polyurethanes (in a similar manner to Leveneur and Isbell's work 54,55 discussed above). Perhaps the only thing missing was a recyclability study.…”

“…In a similar study, Isbell et al studied the epoxidation and then carbonation of castor oil using tetrabutylammonium bromide. 55 Harsh reaction conditions were required to obtain 95% conversion to the carbonate product (100 o C and 100 bar of carbon dioxide for 45 hours), but considering that only 1.4 mol% of tetrabutylammonium bromide was used with respective to epoxidised vegetable oil, this is not surprising. In 2017, Shirakawa et al developed a simple bifunctional triethylamine hydroiodide catalyst, which could ring-open epoxides by providing a Brønsted acidic and nucleophilic site within the same catalyst (in a similar manner to Scheme 1).…”

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

“…229,230 The nature of the halide has thus a clear impact on the overall selectivity of the process, and ketones K are typical byproducts in the formation of iCFAs. 24,116,118,196,212,224,231,232 Ketone formation is attributed to Meinwald rearrangement via a 1,2-hydride shift in the presence of Lewis-or Brønsted acids (Scheme 24, below). 124,233 For example, the formation mechanism of K proposed for YCl 3 is shown in Scheme 25.…”

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

“…Quaternary ammonium and phosphonium halide salts are active species for the cycloaddition of CO 2 to EFAEs and other internal epoxides. However, efficient use of such compounds as catalysts requires reaction temperatures above 120 °C, reaction times spanning over several days and high (≥40 bar) to very high (≈100 bar) CO 2 pressure. Addition of metal‐based Lewis acidic complexes to nucleophilic quaternary salts has the effect to strongly accelerate carbonation of internal epoxides; Fe(II) bispincer‐type, V(V) and Al(III) aminotriphenolate complexes were reported to promote the carbonation of epoxidized methyl oleate (EMO) in the 70–100 °C temperature range under 5–10 bar CO 2 in presence of nucleophilic halide salts.…”