An Organocatalytic Cascade Approach toward Polysubstituted Quinolines and Chiral 1,4-Dihydroquinolines-Unanticipated Effect of N-Protecting Groups
作者:Xinshuai Zhang、Xixi Song、Hao Li、Shilei Zhang、Xiaobei Chen、Xinhong Yu、Wei Wang
DOI:10.1002/anie.201202161
日期:2012.7.16
of a divergent organocatalytic aza‐Michael/aldol cascade process towardquinolines and 1,4‐dihydroquinolines depends on the choice of the N‐protecting group (see scheme; TEA=triethylamine, TMS=trimethylsilyl). Use of an electron‐donating sulfonyl group results in an unanticipated aza‐Michael/aldol/aromatization cascade to give polysubstitutedquinolines (right). In contrast, chiral 1,4‐dihydroquinolines
Synthesis of 2-(1<i>H</i>-Indol-2-yl)acetamides via Brønsted Acid-Assisted Cyclization Cascade
作者:Nicolai A. Aksenov、Dmitrii A. Aksenov、Anton A. Skomorokhov、Lidiya A. Prityko、Alexander V. Aksenov、Georgii D. Griaznov、Michael Rubin
DOI:10.1021/acs.joc.0c01344
日期:2020.10.2
efficient and straightforward Brønsted-acid mediated cascade process was developed, involving cyclization of readily available β-ketonitriles into 2-aminofurans, and their subsequent recyclization into 2-(1H-indol-2-yl)acetamides is developed. This synthetic route opens a new avenue for an expeditious assembly of various isotryptamine derivatives for medicinal chemistry.
A Brønsted acid-promoted asymmetric intramolecular allylic amination of alcohols
作者:Jianqiao Zhou、Hexin Xie
DOI:10.1039/c7ob02599h
日期:——
Reported herein is a chiral Brønsted acid-catalyzed asymmetric intramolecularallylicaminationreaction, allowing facile access to a range of biologically interesting chiral 2-substituted hydroquinolines in up to 90% yield and with up to 93% ee. Furthermore, a significant effect of an N-protecting group was observed in this asymmetric process.
CBr<sub>4</sub> catalyzed activation of α,β-unsaturated ketones
作者:Shyamal Kanti Bera、Rajat Rajiv Maharana、Kousik Samanta、Prasenjit Mal
DOI:10.1039/d2ob01223e
日期:——
the carbonyl group of α,β-unsaturatedketones. Carbon tetrabromide (CBr4) has been used as the sole reagent for the selective synthesis of flavanones and aza-flavanones from the corresponding 2′-hydroxy- and 2′-aminochalcones under metal-free and additive-free conditions. DFT calculations support the catalytic role of XB between the oxygen of chalcones and CBr4 in these reactions.