[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。
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。
A Synthesis of Highly Functionalized Pyrido[2,1-d][1,2,5]triazepines
A synthesis of functionalized 1-(alkylamino)-4-aryl-2,3-dihydro-2-phenylpyrido[2,1-d][1,2,5]triazepines from the sequential reaction between pyridinium ylides, alkyl isocyanides, and 1-[chloro(aryl)methylene]-2-phenylhydrazines in CH2Cl2, in good yields, is described. pyrido[2,1-d][1,2,5]triazepine - hydrazonoyl chloride - alkyl isocyanide - pyridinium ylide - MCR
从吡啶鎓吡啶鎓,烷基异氰酸酯和三价吡啶鎓之间的顺序反应合成功能化的1-(烷基氨基)-4-芳基-2,3-二氢-2-苯基吡啶并[ 2,1- d ] [1,2,5]三氮杂s描述了CH 2 Cl 2中1- [氯(芳基)亚甲基] -2-苯基肼的高收率。 吡啶并[2,1- d ] [1,2,5]三氮平-酰氯-烷基异氰化物-吡啶吡啶-MCR
Studies on furan derivatives. VII. Reactions of .ALPHA.-(2-furyl)-.BETA.-(5-nitro-2-furyl)ethynyl.
作者:AKIRA TANAKA、TOSHINAO USUI
DOI:10.1248/cpb.27.3078
日期:——
Addition of amines to α-(2-furyl)-β-(5-nitro-2-furyl) ethynyl (I) gave N-substituted α-(2-furyl)-β-(5-nitro-2-furyl) vinylamines. Bromination of I gave stereoisomers which were identified as E- and Z-forms, judging from their ultraviolet absorption spectra. The reaction of I with N-substituted pyridinium ylides was not uniform. Only the common indolizines, namely 3-substituted 1-(5-nitro-2-furyl)-2-(2-furyl) indolizines, were obtained by reaction in dioxane, whereas 3-substituted 1-(4-alkylated 5-nitro-2-furyl)-2-(2-furyl)-indolizines were isolated by reaction in dimethylformamide, together with the common indolizines.
在 α-(2-呋喃基)-β-(5-硝基-2-呋喃基)乙炔基(I)上添加胺,可得到 N-取代的 α-(2-呋喃基)-β-(5-硝基-2-呋喃基)乙烯基胺。I 的溴化反应产生了立体异构体,根据它们的紫外吸收光谱,可确定为 E 型和 Z 型。I 与 N-取代的吡啶鎓酰化物的反应并不一致。在二噁烷中反应只得到了常见的吲嗪类化合物,即 3-取代的 1-(5-硝基-2-呋喃基)-2-(2-呋喃基)吲嗪类化合物,而在二甲基甲酰胺中反应则分离出了 3-取代的 1-(4-烷基化的 5-硝基-2-呋喃基)-2-(2-呋喃基)-吲嗪类化合物以及常见的吲嗪类化合物。