[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
Preparation of tetrahydroindolizines from pyridinium and isoquinolinium ylides
作者:Alan R. Katritzky、Nicholas E. Grzeskowiak、Julio Alvarez-Builla
DOI:10.1039/p19810001180
日期:——
Carbonyl- and nitrile-stabilised pyridinium and cyclic azonium methylides condense with chalcones to form tetrahydroindolizines and analogous fused pyrrolidines. The stereochemistry is illuminated by 13C and 1H n.m.r. spectroscopy. Several incorrect literature structures are rectified.
羰基和腈稳定的吡啶鎓和环状的偶氮鎓甲基化物与查耳酮缩合,形成四氢吲哚并二苯并类似的稠合吡咯烷。立体化学由13 C和1 H nmr光谱照亮。纠正了一些错误的文献结构。
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
irradiation of red light-emitting-diode light (λ = 660 nm) to 3-acyl-2-methoxyindolizines in the presence of a catalytic amount of methylene blue triggered the photooxidation of the indolizine ring, resulting in a nearly quantitative release of alcohols or carboxylic acids within a few minutes. The method was applicable for photouncaging various functional molecules such as a carboxylic anticancer drug and
Fluorescent quinolizinium ionic liquids (salts) with unexpectedly high quantum yields up to >99%
作者:Zhengjian Chen、Shiguo Zhang、Xiujuan Qi、Shimin Liu、Qinghua Zhang、Youquan Deng
DOI:10.1039/c1jm11556a
日期:——
Quinolizinium ionic liquids (salts) featuring an unbranched cation core have been prepared, characterized and found to show extremely high fluorescence quantum yields in solution (Φf > 99%, λem near 334 nm) and bright cyan fluorescence in molten state (λem near 465 nm).