Synthesis of imidazole-fused pentacyclic pyrrolo[3,4-c]coumarins via base-promoted rearrangement of coumarin-substituted N-heterocyclic carbene precursors

Karatas, Mert OlgunOzdemir, NamikKucukbay, Hasan2026-04-042026-04-0420241144-05461369-9261https://doi.org/10.1039/d4nj03146fhttps://hdl.handle.net/11616/109313Pentacyclic pyrrolocoumarin scaffolds are unique structural motifs that form the backbone of many bioactive compounds. Herein, we report the first-time synthesis of imidazole-fused pentacyclic pyrrolo[3,4-c]coumarin derivatives (2) through the stoichiometric reaction between coumarin-substituted N-heterocyclic carbene (NHC) precursors (1) and Pd(OAc)(2), in the presence of an external base. Control experiments revealed that the base-promoted rearrangement of the NHC precursors yields N-(alkyl)aniline-substituted pyrrolo[3,4-c]coumarin derivatives (3), wherein the imidazole ring is opened. Additionally, the formation of 2via the reaction of 3 and Pd(OAc)(2 )indicated that the formation of pentacyclic pyrrolo[3,4-c]coumarin occurs via the base-promoted rearrangement product of NHC precursors.eninfo:eu-repo/semantics/closedAccessComplexesLamellarinsInhibitorsSilver(I)MoistureNhcSynthesis of imidazole-fused pentacyclic pyrrolo[3,4-c]coumarins via base-promoted rearrangement of coumarin-substituted N-heterocyclic carbene precursorsArticle4838166761668210.1039/d4nj03146f2-s2.0-85203787765Q2WOS:001311226200001Q30000-0001-8500-20880000-0002-7180-94860000-0003-3371-9874