Organocatalytic Synthesis of Substituted Vinylene Carbonates

The organocatalytic synthesis of substituted vinylene carbonates from benzoins and acyloins was studied using diphenyl carbonate as a carbonyl source. A range of N-Heterocyclic Carbene (NHC) precursors were screened and it was found that imidazolium salts were the most active for this transformation. The reaction occurs at 90 degrees C under solvent-free conditions. A wide range of substituted vinylene carbonates (symmetrical and unsymmetrical, aromatic or aliphatic), including some derived from natural products, were prepared with 20-99% isolated yields (24 examples). The reaction was also developed using thermomorphic polyethylene-supported organocatalysts as recoverable and recyclable species. The use of such species facilitates the workup and allows the synthesis of vinylene carbonates on the preparative scale (>30 g after 5 runs).

Automated summary

The study investigated the organocatalytic synthesis of substituted vinylene carbonates using diphenyl carbonate as a carbonyl source. Imidazolium salts were found to be the most effective catalysts for this transformation. The reaction yielded a variety of substituted vinylene carbonates with isolated yields ranging from 20-99%. Additionally, thermomorphic polyethylene-supported organocatalysts were utilized for recoverable and recyclable species, allowing for multiple runs and preparative scale synthesis.