constructed from indoles and cyclohexanone derivatives using a combination of catalytic niobic acid-on-carbon (Nb2O5/C) and palladium-on-carbon (Pd/C) under heating conditions without any oxidants. The Lewis acidic Nb2O5/C promoted the nucleophilic addition of indoles to the cyclohexanones, and the subsequent dehydration and Pd/C-catalyzed dehydrogenation produced the 3-arylindoles. The additive 2
β-Selective C–H Arylation of Pyrroles Leading to Concise Syntheses of Lamellarins C and I
作者:Kirika Ueda、Kazuma Amaike、Richard M. Maceiczyk、Kenichiro Itami、Junichiro Yamaguchi
DOI:10.1021/ja508449y
日期:2014.9.24
The first generalβ-selectiveC-Harylation of pyrroles has been developed by using a rhodium catalyst. This C-Harylation reaction, which is retrosynthetically straightforward but results in unusual regioselectivity, could result in de novo syntheses of pyrrole-derived natural products and pharmaceuticals. As such, we have successfully synthesized polycyclic marine pyrrole alkaloids, lamellarins C
Pd-catalyzed imine-directed intramolecular C N bond formation through C(sp3) H activation: An efficient approach to multisubstituted pyrroles
作者:Ting Yu、Qiang Zhu、Shuang Luo
DOI:10.1016/j.tetlet.2020.151887
日期:2020.5
An atom-economic approach to synthesize 1,2,4-trisubstituted pyrroles through palladium-catalyzed imine-directed intramolecularC(sp3)H amination reaction has been developed. The imine group acts as a directing group as well as an intramolecular nucleophile for the first time in intramolecular CN bonds formation reactions.
sustainable, highly regiospecific substituted pyrroles were synthesized using a well-defined, air stable, molecular iron(0) complex. The developed methodology is broadly applicable and tolerates a variety of functional groups. C-2, C-3, and C-2 & C-4 substituted pyrroles were synthesized in good yield. Symmetrical bis-pyrroles were accessible for the first time using an ironcatalyst. On the basis of the experimental
A simple preparation of N-substituted 3-pyrroline boromic esters from primary amines is described. The Suzuki-Miyaura coupling of these heterocycles with aryl halides proceeds in good yields. Alternatively, oxidation withDDQ or MnO 2 gives the corresponding pyrroles, which can be also engaged in subsequent palladium cross-coupling reactions.