Pd-Catalyzed C-3 functionalization of indolizines via C–H bond cleavage
作者:Baoli Zhao
DOI:10.1039/c2ob25643f
日期:——
New transition metal-catalyzed methods for the arylation of indolizines by the direct cleavage of CâH bonds have been developed. A wide range of aryltrifluoroborate salts react with indolizines in the presence of Pd(OAc)2 catalyst and AgOAc oxidant to give the arylated indolizines in high yields. Both electron-donating and electron-withdrawing groups perform smoothly while bromide and chlorine substituents are tolerated. In addition, the indolizines display similar reactivities in the Pd-catalyzed reaction with 3-phenylpropiolic acid to afford the corresponding C-3 alkynylated indolizines. These methods allow the direct functionalization of indolizines in one step.
efficiently prepared by direct C-3 arylation of indolizines using sodium arylsulfinates and arylsulfonylhydrazides. Pd-catalyzed desulfitative C-3 arylation with sodium arylsulfinates was achieved with the assistance of peroxides, and the catalytic efficiency was promoted by N-containing ligands. Arylsulfonylhydrazides were also successfully applied in Pd-catalyzed desulfitative C-3 arylation with indolizines
Formation of indolizines by the addition of α-chloroacrylonitrile to pyridinium ylides: regioselectivity and Hammett correlation
作者:Roland Bonneau、Michael T. H. Liu、René Lapouyade
DOI:10.1039/p19890001547
日期:——
Cycloaddition of pyridiniumylides to α-chloroacrylonitrile give indolizines: the regioselectivity of the reaction can be rationalized in terms of nucleophilic attack by the ylides on the olefin.
Copper-Catalyzed Oxidative Coupling–Annulation: One-Pot Synthesis of Indolizines from 2-Alkylazaarenes with Alkenes
作者:Ying Liang、Ying-ming Pan、Jing-ling Liu、Heng-shan Wang
DOI:10.1055/s-0034-1378785
日期:——
A novel copper-catalyzed highly selective oxidative coupling-annulation of 2-alkylazaarenes with terminal alkenes was achieved. This process provides a simple, efficient, and atom-economic way to construct indolizines in good yields.
Silver-mediated synthesis of indolizines via oxidative C–H functionalization and 5-endo-dig cyclization
作者:Amit N. Pandya、James T. Fletcher、Eric M. Villa、Devendra K. Agrawal
DOI:10.1016/j.tetlet.2014.10.112
日期:2014.12
An efficient strategy for the synthesis of indolizines from readily available starting materials via oxidative C-H functionalization and 5-endo-dig cyclization in one step has been demonstrated. This protocol represents wide substrate scope, high functional group tolerance, and selectivity. The structure of the product was confirmed by X-ray crystallographic studies. Ag2CO3 required of this tandem reaction can be recycled and reused after undergoing oxidative reaction. (C) 2014 Elsevier Ltd. All rights reserved.