Palladium-catalyzed reductive N-heterocyclization of alkenyl-substituted nitroarenes as a viable method for the preparation of bicyclic pyrrolo-fused heteroaromatic compounds

• Published in: Tetrahedron Vol. 66; no. 10; pp. 1800 - 1805
• Main Authors: Gorugantula, Sobha P., Carrero-Martínez, Grissell M., Dantale, Shubhada W., Söderberg, Björn C.G.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 06.03.2010; Elsevier
• Subjects: Chemistry; Chemistry, Organic; Exact sciences and technology; Fused pyrroles; Heterocyclic compounds; Heterocyclic compounds with n hetero atom and also o and/or s, se, te hetero atoms; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Organic chemistry; Palladium-catalyzed; Physical Sciences; Preparations and properties; Reductive-cyclization; Science & Technology; Fused pyrroles; Reductive-cyclization; Palladium-catalyzed; EFFICIENT SYNTHESIS; REACTIVITY; INHIBITORS; PYRROLOPYRIDAZINES; Nitro compound; Sulfur nitrogen heterocycle; Catalytic reaction; Nitrogen heterocycle; Thiazole derivatives; Palladium complex; Pyrrole derivatives; Chemical reduction; Alkene; Cyclization; Bicyclic compound; Pyridazine derivatives; Aromatic compound; Carbon monoxide; Chemical synthesis; Heterocyclization; Ethylenic compound
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2010.01.029

Palladium-catalyzed, carbon monoxide-mediated reductive N-heterocyclization of nitro-heteroaromatic compounds having an alkene adjacent to the nitro-group affords bicyclic pyrrolo-fused heteroaromatic molecules. This type of reaction was used to prepare the fused bicyclo[3.3.0] ring-system: thieno[3,2- b]pyrrole, thieno[2,3- b]pyrrole, furo[2,3- b]pyrrole, pyrrolo[3,2- d]thiazole, and pyrrolo[2,3- d]imidazole and the bicyclo[4.3.0] ring-systems: pyrrolo[3,2- b]pyridine, pyrrolo[2,3- b]pyridine, pyrrolo[3,2- c]pyridine, pyrrolo[2,3- c]pyridine, pyrrolo[3,2- c]pyridazine, and pyrrolo[3,2- d]pyrimidine in 32–94% yield. [Display omitted]