The First Approach to the Synthesis of 1-Unsubstituted 2-Arylindolizines by Intramolecular 1,5-Dipolar Cyclization of 2-(2-Arylethenyl)pyridinium Ylides in the Presence of Tetrakis(pyridine)cobalt (II) Dichromate
The First Approach to the Synthesis of 1-Unsubstituted 2-Arylindolizines by Intramolecular 1,5-Dipolar Cyclization of 2-(2-Arylethenyl)pyridinium Ylides in the Presence of Tetrakis(pyridine)cobalt (II) Dichromate
Synthesis of 5-(2-Phenylethenyl)indolizines by Selective Intermolecular 1,3-Dipolar Cycloaddition of 2-(2-Phenylethenyl)pyridinium N-Ylide with Alkenes Promoted by Tetrakis-pyridine Cobalt(ii) Dichromate
作者:Jian Zhou、Yuefei Hu、Hongwen Hu
DOI:10.1039/a805058i
日期:——
Intermolecular 1,3-dipolarcycloadditions of 2-(2-phenylethenyl)pyridinium N-ylides (3a–d) with electron-deficient alkenes (5a–d) were carried out selectively in the presence of tetrakis-pyridinecobalt(II) dichromate to yield 5-(2-phenylethenyl)indolizines (6a–j) in moderate yields (48–63%).
The First Approach to the Synthesis of 1-Unsubstituted 2-Arylindolizines by Intramolecular 1,5-Dipolar Cyclization of 2-(2-Arylethenyl)pyridinium Ylides in the Presence of Tetrakis(pyridine)cobalt (II) Dichromate
作者:Jian Zhou、Yuefei Hu、Hongwen Hu
DOI:10.1055/s-1999-3673
日期:——
The first approach to the preparation of 1-unsubstituted 2-arylindolizines by intramolecular 1,5-dipolar cyclization of 2-(2-arylethenyl)pyridinium ylides 2a-v in the presence of tetrakis(pyridine)cobalt (II) dichromate was developed. Several kinds of novel 1-unsubstituted 2-aryl-3-acetyl-, 3-benzoyl-, 3-ethoxycarbonyl- and 3-(4-nitrobenzoyl)indolizines 3a-v were synthesized under the mild conditions in reasonable to moderate yields.