Synthesis of 1,2,3-triarylpyrroles from 1-benzylbenzotriazoles<i>via</i>[1 + 2 + 2] annulation
作者:Alan R. Katritzky、Zouquan Wang、Jianqing Li、Julian R. Levell
DOI:10.1002/jhet.5570340448
日期:1997.7
1,2,3-Triarylpyrroles 7 have been synthesized by sequential lithiation and alkylation of 1-benzylbenzo-triazoles 1 with 2-bromoacetaldehyde diethyl acetal (2) and N-benzylideneaniline (4), followed by treatment with formic acid in ethanol.
A new metal-free synthesis of pyrrole from allyl ketone and amine has been established. The reaction proceeds via an thiolative activation of the C–C double bond with dimethyl(methylthio)sulfonium trifluoromethanesulfonate, followed by a nucleophilic ring-opening addition of primary amine to the generated episulfonium intermediate, and then an internal condensation and aromatization. This mild procedure
Enone–Alkyne Reductive Coupling: A Versatile Entry to Substituted Pyrroles
作者:Benjamin B. Thompson、John Montgomery
DOI:10.1021/ol201133n
日期:2011.7.1
The reductive coupling of enones or enals with alkynes, followed by olefin oxidative cleavage and Paal-Knorr cyclization, provides a versatile entry to a variety of pyrrole frameworks. A number of limitations of alternate entries to the requisite 1,4-dicarbonyl intermediate are avoided. Classes of pyrroles that are accessible by this approach include 2,3-, 2,4-, 1,2,3-, 1,2,4-, 2,3,5-, and 1,2,3,5-substituted monocyclic pyrroles as well as a number of fused-ring polycyclic derivatives.
Almstroem, Justus Liebigs Annalen der Chemie, 1913, vol. 400, p. 140