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。
One-pot tandem cyclisation to pyrrolo[1,2-<i>a</i>][1,4]benzodiazepines: a modified approach to the Pictet–Spengler reaction
We have reported a one-pot two-step methodology for the synthesis of highly condensed heterocycles, pyrrolo[1,2-a][1,4]benzodiazepines, by a modified Pictet–Spengler reaction under mild conditions in a short time. Our approach has a few advantages over the conventional two components synthesis as it is step and atom economic, environmentally benign and a convergent synthetic method. We have discussed
我们已经报道了在改良的Pictet-Spengler反应中在短时间内在改良的Pictet-Spengler反应中合成高浓缩杂环,吡咯并[1,2- a ] [1,4]苯并二氮杂物的一锅两步方法。我们的方法相对于常规的两组分合成方法具有一些优势,因为它是一步法和原子经济,对环境有益的方法,并且是一种收敛的合成方法。我们在这里讨论了这种新颖方法的广泛的基质范围。
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
Thiol-mediated tandem Michael–aldol reaction: a convenient method for the synthesis of fused cyclopentenones
作者:Shubhankar Samanta、Nasima Yasmin、Debasish Kundu、Jayanta K. Ray
DOI:10.1016/j.tetlet.2010.05.142
日期:2010.8
A simple, convenient, one-pot synthetic approach towards substituted cyclopentenone derivatives via thiol-mediated tandem Michael–aldol reaction followed by acid-catalyzed thiol elimination and isomerization of 3-(2-formyl-3,4-dihydronapthalene 1-yl)-acrylic acid esters has been developed.