Divergent Synthesis of Highly Substituted Pyridines and Benzenes from Dienals, Alkynes, and Sulfonyl Azides
作者:Han Luo、You Li、Luan Du、Xiaolan Xin、Tao Wang、Jingpeng Han、Yi Tian、Baosheng Li
DOI:10.1021/acs.orglett.1c02900
日期:2021.10.15
Divergent synthesis is extremely important for the highly efficient preparation of structurally diverse target molecules. Herein, we describe a multicomponent cascade reaction, which allows access to highly substituted pyridines and benzenes by combining four individual steps in a one-pot manner from the same set of readily available starting materials. The azepine intermediates were first used as
One-pot synthesis of highly fluorescent polycyclic benzimidazole derivatives
作者:Susanta Kumar Manna、Suresh Kumar Mondal、Atiur Ahmed、Arabinda Mandal、Atanu Jana、Mohammed Ikbal、Shubhankar Samanta、Jayanta K. Ray
DOI:10.1039/c3ra44521f
日期:——
An efficient one pot synthesis of polycyclic benzimidazole derivatives has been developed (up to 90% yield). The protocol is very mild, metal-free, and not restricted to anhydrous conditions. It also demonstrates an example of preferential electrocyclic reaction over Michael reaction. These new benzimidazole derivatives are highlyfluorescent and show a dramatic change with pH; The characteristic bright
An unprecedented functional group assisted CuI‐catalyzed defunctionalization reaction has been developed. The simple strategy can remove the ester with the methylene group (–CH2CO2R) from a large array of N‐pyridinyl pyrrolo esters. In addition to the synthesis, an interesting extensive mechanistic study with evidence on the roles of both CuI and the N‐pyridinyl ring is also reported.
已经开发出前所未有的官能团辅助的Cu I催化的去官能化反应。简单的策略可以从大量N-吡啶基吡咯烷酸酯中除去带有亚甲基的酯(–CH 2 CO 2 R)。除了合成以外,还报道了一项有趣的广泛的机理研究,该研究提供了有关Cu I和N-吡啶基环的作用的证据。
Synthesis of phthalides utilizing a one-pot intramolecular domino protocol
作者:Nasima Yasmin、Jayanta K. Ray
DOI:10.1039/c3ra45117h
日期:——
A number of (E)-3-alkylidine-phthalide derivatives have been prepared at room temperature in excellent yields in a one-pot reaction by treating o-alkenylbenzoic acids with meta-chloroperbenzoic acid and para-toluenesulfonic acid. This reaction presumably occurs via domino epoxidation – intramolecular cyclization – acid catalyzed dehydration sequence of reactions. On the other hand, 3-(2-formyl-3,4-dihydro-naphthalen-1-yl)-acrylic acid esters and 3-(2-formyl-3,4-dihydro-naphthalen-1-yl)-acrylonitriles afforded phthalide derivatives under Pinnick reaction conditions involving oxidation-intramolecular Michael addition.
An efficient synthetic protocol of pyrroles and isoquinolines through NaN3/NH4Cl promoted intramolecular aza-annulation of formyl group with suitable alkenes or alkynes is described in high yield and regioselectivities. The metal free exo-trig and endo-dig aza-cyclisation has been extended for the synthesis of bicyclic or tricyclic pyrroles along with environment sensitive fluorescent isoquinoline