Ipso Substitution as a Route to Benzo[<i>c</i>]quinolizines and 4-Hydroxycoumarins
作者:Yannan Liu、Mark J. Kurth
DOI:10.1021/jo0161126
日期:2002.4.1
A convenient ipso substitution method for the preparation of benzo[c]quinolizine (2) and 4-hydroxy-3-(2'-pyridyl)coumarin (3) has been developed. The intramolecular nucleophilic substitution reaction of 3-oxo-2-(2'-pyridyl)-(2-halophenyl)propanoate (1) in refluxing xylenes gives initially benzo[c]quinolizine, while further heating results in the formation of 4-hydroxycoumarin. A mechanism has been
External‐Photocatalyst‐Free Visible‐Light‐Mediated Synthesis of Indolizines
作者:Basudev Sahoo、Matthew N. Hopkinson、Frank Glorius
DOI:10.1002/anie.201506868
日期:2015.12.14
A visible‐light‐mediatedsynthesis of valuable polycyclic indolizine heterocycles from easily accessed brominated pyridine and enol carbamate derivatives has been developed. This process, which operates at room temperature under irradiation from readily available light sources, does not require the addition of an external photocatalyst. Instead, an investigation into the reaction mechanism indicates
Transannulation of Pyridotriazoles with Naphthoquinones and Indoles: Synthesis of Benzo[
<i>f</i>
]Pyrido[1,2‐
<i>a</i>
]Indoles and Indolizino[3,2‐
<i>b</i>
]indoles
作者:Deepa Rawat、Subbarayappa Adimurthy
DOI:10.1002/adsc.202100965
日期:2022.1.4
Ruthenium catalysed denitrogenative transannulation of pyridotriazoles with naphthoquinones provided the transannulated benzo[f]pyrido[1,2-a]indoles derivatives in good to excellent yields. While pyridotriazoles with indoles in presence of PivOH and oxone yield indolizino[3,2-b]indoles under metal-free conditions. Quinone annulation proceeds through ruthenium-carbenoid intermediate while indole annulation
钌催化的吡啶并三唑与萘醌的脱氮环化提供了苯并[ f ]吡啶并[1,2- a ]吲哚衍生物的良好到优异的产率。而在 PivOH 和 oxone 存在下,吡啶并三唑与吲哚一起在无金属条件下产生吲哚并 [3,2- b ] 吲哚。醌环化通过钌-卡宾中间体进行,而吲哚环化可以通过重氮-吡啶鎓中间体进行。对照实验表明两种转化都遵循离子机制。
Transesterification of Methyl Arylacetates with Lithium Alkoxides
作者:Baburao M. Bhawal、Subhash P. Khanapure、Edward R. Biehl
DOI:10.1055/s-1991-26391
日期:——
A series of methyl arylacetates were transesterified in excellent yields using lithium alkoxides derived from primary, secondary, and tertiary aliphatic alcohols, benzyl alcohols, and allyl alcohol.