[3 + 2]-Annulation of <i>gem</i>-Difluoroalkenes and Pyridinium Ylides: Access to Functionalized 2-Fluoroindolizines
作者:Jun-Qi Zhang、Dandan Hu、Jinyu Song、Hongjun Ren
DOI:10.1021/acs.joc.0c03041
日期:2021.3.19
A [3 + 2]-annulation of gem-difluoroalkenes and pyridinium ylides was developed employing ambient air as the sole oxidant in an open-vessel manner, affording a series of multifunctionalized 2-fluoroindolizines in moderate to good yields. In this reaction, gem-difluoroalkene acts as a C2 synthon and entirely avoids the competitive addition–elimination process, which provides facile access to 2-fluoroindolizines
Rh(III)-Catalyzed Oxidative Annulation Leading to Substituted Indolizines by Cleavage of C(sp<sup>2</sup>)–H/C(sp<sup>3</sup>)–H Bonds
作者:Bingxue Shen、Bin Li、Baiquan Wang
DOI:10.1021/acs.orglett.6b01181
日期:2016.6.17
Rhodium(III)-catalyzed oxidative annulation reactions of pyridinium trifluoromethanesulfonate salts with alkynes leading to substituted indolizines by cleavage of C(sp2)–H/C(sp3)–H bonds are developed. The starting materials are readily available, and the reactions have a broad substrate scope. This reaction overcomes some drawbacks of the previous indolizine synthetic methods and provides a new efficient
Synthesis of Indolizines from Pyridinium Salts and Ethyl Bromodifluoroacetate
作者:Xiaoya Hou、Sen Zhou、Yuli Li、Minjie Guo、Wentao Zhao、Xiangyang Tang、Guangwei Wang
DOI:10.1021/acs.orglett.0c03540
日期:2020.12.4
Here we present a novel annulation of pyridinium salts with BrCF2CO2Et to access the indolizine derivatives with high efficiency. The α substitution of pyridine plays a key role in determining the reaction pathways. Various types of indolizines can be conveniently accessed from easily available pyridinium salts under mild and simple reaction conditions.
在这里,我们提出了一种新型的吡啶盐与BrCF 2 CO 2 Et的环化方法,以高效地获得吲哚嗪衍生物。吡啶的α取代在确定反应途径中起关键作用。在温和而简单的反应条件下,可以从容易获得的吡啶鎓盐中方便地获得各种类型的吲哚嗪。
Metal-free synthesis of novel indolizines from chromones and pyridinium salts via 1,3-dipolar cycloaddition, ring-opening and aromatization
作者:Kai-Kai Dong、Qiang Huang
DOI:10.1016/j.tetlet.2019.04.056
日期:2019.7
efficient, and economical synthetic approach to construct a variety of stucturally novelindolizines bearing a phenolic hydroxy group has been developed through 1,3-dipolar cycloaddition of chromones and pyridinium salts. The methodology is tolerant of a wide range of functional groups and applicable to library synthesis.