Silver-Catalyzed Cascade Reaction of β-Enaminones and Isocyanoacetates To Construct Functionalized Pyrroles
作者:Guichun Fang、Jianquan Liu、Junkai Fu、Qun Liu、Xihe Bi
DOI:10.1021/acs.orglett.7b00201
日期:2017.3.17
reported. In this reaction, tautomericequilibria of β-enaminones are utilized to generate imine partners in situ. A hypothesized sequential Mannich addition/cyclization of imine tautomers and isocyanoacetates followed by an unprecedented ring-opening of the resultant 2-imidazolines and dehydration–condensation deliver the final 1,2,4,5-tetrasubstituted pyrrole products.
Enaminones 2, easily prepared from the corresponding sodium salts of beta -ketoaldehydes 1 and hydrochlorides of primary amines, react with carbon disulfide/sodium hydride to give dithiocarbamates 3 after alkylation. In a similar way thiocarbamoylation yields isothioureas 4. The C-13 NMR parameters of 2, 3 and 4 show significant low- and high-field shifts of the C-1 and C-2 signals, respectively.
Claisen, Justus Liebigs Annalen der Chemie, 1897, vol. 297, p. 57
作者:Claisen
DOI:——
日期:——
Mayadeo, M. S.; Gandhi, S. A., Journal of the Indian Chemical Society, 1994, vol. 71, # 5, p. 281 - 282
作者:Mayadeo, M. S.、Gandhi, S. A.
DOI:——
日期:——
Mapara; Desai, Journal of the Indian Chemical Society, 1955, vol. 32, p. 52