Synthesis of Mesomeric Betaines, Quinoliziniumides, via Back-donated 1,6-Cyclization
摘要:
The reaction of 3-aminopyridinium salts (4) with polarized olefins (2a,b, 3) in the presence of triethylamine yielded the corresponding 3-aminopyridinium N-allylides (5). Thermolysis of 3-aminopyridinium N-allylides (5a-c,h-j,l-n) in refluxing xylene afforded the 1,5-dipolar cyclization products, 8-aminoindolizines (6) together with the back-donated 1,6-cyclization products, quinoliziniumides (7). In addition, thermolysis of N-allylides (5a-c,h-j,l-n) in refluxing AcOH gave quinoliziniumides (7).
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。
Synthesis of Mesomeric Betaines, Quinoliziniumides, via Back-donated 1,6-Cyclization
The reaction of 3-aminopyridinium salts (4) with polarized olefins (2a,b, 3) in the presence of triethylamine yielded the corresponding 3-aminopyridinium N-allylides (5). Thermolysis of 3-aminopyridinium N-allylides (5a-c,h-j,l-n) in refluxing xylene afforded the 1,5-dipolar cyclization products, 8-aminoindolizines (6) together with the back-donated 1,6-cyclization products, quinoliziniumides (7). In addition, thermolysis of N-allylides (5a-c,h-j,l-n) in refluxing AcOH gave quinoliziniumides (7).