Iron-Catalyzed Indolizine Synthesis from Pyridines, Diazo Compounds, and Alkynes
作者:Tim Douglas、Anca Pordea、James Dowden
DOI:10.1021/acs.orglett.7b03252
日期:2017.12.1
The iron(III)-catalyzed synthesis of indolizines from commercially available alkyne, pyridine, and diazo precursors is reported. This mild, expedient method is tolerant of various solvents and proceeds with as little as 0.25 mol % [Fe(TPP)Cl]. Significantly, this multicomponent reaction is compatible with electrophilic alkynes; control experiments demonstrate the importance of the catalyst in promoting
A highlyenantioselectivesynthesis of tetrahydroindolizines by catalytic multicomponent cycloaddition reactions of diazoacetate, pyridine, and alkenyloxindole was developed. Under the relay catalysis, involving an achiral iron(III) catalyst and chiral N,N′‐dioxide‐scandium(III) complex, a series of tetrahydroindolizines bearing different substituents were obtained in moderate to high yields (up to
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。
Enantioselective dicarbofunctionalization of (<i>E</i>)-alkenyloxindoles with pyridinium salts by chiral Lewis acid/photo relay catalysis
A highly efficient enantioselective dicarbofunctionalization reaction of (E)-alkenyloxindoles with pyridinium salts was realized. The process includes the chiral N,N′-dioxide–Sc(III) complex-catalyzed regio-, diastereo-, and enantioselective [3+2] cycloaddition reaction and the following photo-promoted aza-Norrish II type rearrangement. A series of 2-pyridyl substituted oxindole derivatives were obtained
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.