One-pot synthesis of indolizine via 1,3-dipolar cycloaddition using a sub-equivalent amount of K2Cr2O7 as an efficient oxidant under base free conditions
摘要:
X = 氯或溴;EWG1,EWG2 = 电子吸引基团,一锅法反应,29个例子,产率从中等到高,克级放大潜力得到确认。
Transition-Metal-Free Synthesis of Indolizines from Electron-Deficient Alkenes via One-Pot Reaction Using TEMPO as an Oxidant
作者:Yu Zhang、Huayou Hu、Fei Shi、Zhaole Lu、Xiaolei Zhu、Weiqiu Kan、Xiang Wang
DOI:10.1055/s-0035-1560973
日期:——
Abstract A one-pot method for the synthesis of multisubstituted indolizines from α-halo carbonyl compounds, pyridines, and electron-deficient alkenes is reported. The oxidative dehydrogenation reaction takes place under transition-metal-free conditions using TEMPO as an oxidant. This protocol uses ready available starting materials in a convenientprocedure under mild reaction conditions. A one-pot method
A transition metal-free iodinecatalyzedsynthesis of indolizine derivatives through [3+2] cyclization of 2-pyridylesters and chalcones has been described. The method is efficient to synthesize a variety of substituted indolizines including hetero aromatic indolizines. Mechanistic studies reveal that, the reaction follows the radical pathway.
Synthesis of indolizine-1-carboxylates through the Ortoleva-King reaction of 2-pyridylacetate followed by the Aldol condensation under mild reaction conditions has been described. This protocol is compatible with a broad range of functional groups, and it has been also successfully extended to unsaturated ketones, bringing about the regioselective formation of benzoyl-substituted indolizines through Michael addition followed by C-N bond formation, which are difficult to prepare by previous methods in a single step.
Bue, G. De; Nasielski, J., Bulletin des Societes Chimiques Belges, 1997, vol. 106, # 2, p. 97 - 108
作者:Bue, G. De、Nasielski, J.
DOI:——
日期:——
MIKI, YASUYOSHI;HIROISHI, YUJI;HACHIKEN, HIROKO;TAKEMURA, SHOJI, J. HETEROCYCL. CHEM., 28,(1991) N, C. 45-48