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 N-Heterocyclic Carbene (NHC) precursors were screened it found that imidazolium salts the most active for this transformation. reaction occurs at 90 °C under solvent-free conditions. wide (symmetrical unsymmetrical, aromatic or aliphatic), including some derived natural products, prepared with 20–99% isolated yields (24 examples). also developed thermomorphic polyethylene-supported organocatalysts recoverable recyclable species. use such species facilitates workup allows on preparative scale (>30 g after 5 runs).