Tunable Pd-Catalyzed Cyclization of Indole-2-carboxylic Acid Allenamides: Carboamination vs Microwave-Assisted Hydroamination
摘要:
A variety or 3-vinyl-subtituted imidazo[1.5-a]indole derivatives were synthesized by intramolecular Pd-catalyzed cyclization oh the title allenamides through either a domino carbopalladation/exo-cyclization process or a novel hydroamination reaction that proceeds smoothly under microwave irradiation Both the observed pathways involve a pi-allyl-palladmin(II) complex arising from insertion of the allelic group into it palladium(II) species. the latter being formed In situ by the intervention of an aryl iodide or of the N-H group In both cases the role of nucleophile is covered by the Indole nitrogen
Tunable Pd-Catalyzed Cyclization of Indole-2-carboxylic Acid Allenamides: Carboamination vs Microwave-Assisted Hydroamination
作者:Egle M. Beccalli、Alice Bernasconi、Elena Borsini、Gianluigi Broggini、Micol Rigamonti、Gaetano Zecchi
DOI:10.1021/jo101501u
日期:2010.10.15
A variety or 3-vinyl-subtituted imidazo[1.5-a]indole derivatives were synthesized by intramolecular Pd-catalyzed cyclization oh the title allenamides through either a domino carbopalladation/exo-cyclization process or a novel hydroamination reaction that proceeds smoothly under microwave irradiation Both the observed pathways involve a pi-allyl-palladmin(II) complex arising from insertion of the allelic group into it palladium(II) species. the latter being formed In situ by the intervention of an aryl iodide or of the N-H group In both cases the role of nucleophile is covered by the Indole nitrogen
Pd/Brønsted acid catalysed intramolecular <i>N</i>-allylation of indoles and pyrroles with alkynes for the synthesis of N-fused heterocycles
N-allylation of indoles and pyrroles with alkynes for the synthesis of biologically important imidazolidinone-fused N-heterocycles. The allylation is completely atom-economical and is applicable to a wide range of substrates. The methodology eliminates the use of a leaving group or an oxidizing agent, often employed for the allylation of nucleophiles. To the best of our knowledge, N-allylation of indoles and pyrroles