Metal-Free Synthesis of Pyrrolo[1,2-a]quinoxalines Mediated by TEMPO Oxoammonium Salts

Synthesis ◽  
2018 ◽  
Vol 50 (14) ◽  
pp. 2727-2740 ◽  
Author(s):  
Xiang-Ying Tang ◽  
Yue-fa Gong ◽  
Heng-rui Huo

We herein describe a novel TEMPO oxoammonium salt initiated Pictet–Spengler reaction of imines, generated in situ from carbonyl compounds and pyrrole- or indole-containing substrates, to afford 4,5-dihydropyrrolo[1,2-a]quinoxalines or 5,6-dihydroindolo[1,2-a]quin­oxalines in good to excellent yields. Moreover, a one-pot synthesis of a biologically important quinoxaline is achieved via a cyclization–dehydrogenation process using one equivalent of the oxoammonium salt.

2020 ◽  
Vol 18 (3) ◽  
pp. 551-556 ◽  
Author(s):  
Satyajit Samanta ◽  
Sougata Santra ◽  
Rana Chatterjee ◽  
Adinath Majee

One-pot synthesis of bis(β,β′-dialkoxy carbonyl) derivatives has been reported by the oxidative cleavage of aziridines.


RSC Advances ◽  
2015 ◽  
Vol 5 (128) ◽  
pp. 105699-105706 ◽  
Author(s):  
Adrián A. Heredia ◽  
Alicia B. Peñéñory

One-pot synthesis of alkyl styryl selenides using KSeCN as selenium source.


2020 ◽  
Vol 24 (8) ◽  
pp. 900-908
Author(s):  
Ram Naresh Yadav ◽  
Amrendra K Singh ◽  
Bimal Banik

Numerous O (oxa)- and S (thia)-glycosyl esters and their analogous glycosyl acids have been accomplished through stereoselective glycosylation of various peracetylated bromo sugar with benzyl glycolate using InBr3 as a glycosyl promotor followed by in situ hydrogenolysis of resulting glycosyl ester. A tandem glycosylating and hydrogenolytic activity of InBr3 has been successfully investigated in a one-pot procedure. The resulting synthetically valuable and virtually unexplored class of β-CMGL (glycosyl acids) could serve as an excellent potential chiral auxiliary in the asymmetric synthesis of a wide range of enantiomerically pure medicinally prevalent β-lactams and other bioactive molecules of diverse medicinal interest.


Author(s):  
Romana Pajkert ◽  
Henryk Koroniak ◽  
Pawel Kafarski ◽  
Gerd Volker Roeschenthaler

A one-pot, regioselective 1,3-dipolar cycloaddition of in situ generated (diethoxyphosphoryl)difluoromethyl nitrile oxide toward selected alkenes and alkynes is reported. This protocol enables facile access to 3,5-disubstituted isoxazolines and isoxazoles bearing...


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1466
Author(s):  
Ye Eun Kim ◽  
Hyunsung Cho ◽  
Yoo Jin Lim ◽  
Chorong Kim ◽  
Sang Hyup Lee

Studies on a one-pot synthesis of novel multisubstituted 1-alkoxyindoles 1 and their mechanistic investigations are presented. The synthesis of 1 was successfully achieved through consecutive four step reactions from substrates 2. The substrates 2, prepared through a two-step synthetic sequence, underwent three consecutive reactions of nitro reduction, intramolecular condensation, and nucleophilic 1,5-addition to provide the intermediates, 1-hydroxyindoles 8, which then were alkylated in situ with alkyl halide to afford the novel target products 1. We optimized the reaction conditions for 1 focusing on the alkylation step, along with the consideration of formation of intermediates 8. The optimized condition was SnCl2·2H2O (3.3 eq) and alcohols (R1OH, 2.0 eq) for 1–2 h at 40 °C and then, base (10 eq) and alkyl halides (R2Y, 2.0 eq) for 1–4 h at 25–50 °C. Notably, all four step reactions were performed in one-pot to give 1 in good to modest yields. Furthermore, the mechanistic aspects were also discussed regarding the reaction pathways and the formation of side products. The significance lies in development of efficient one-pot reactions and in generation of new 1-alkoxyindoles.


2020 ◽  
Vol 22 (14) ◽  
pp. 4550-4560
Author(s):  
Wenjuan Fang ◽  
Zhencai Zhang ◽  
Zifeng Yang ◽  
Yaqin Zhang ◽  
Fei Xu ◽  
...  

A synthetic strategy for bio-based polycarbonate was developed via one-pot polymerization of renewable monomer isosorbide and dimethyl carbonate using eco-friendly organo-catalysts.


ChemInform ◽  
2012 ◽  
Vol 43 (52) ◽  
pp. no-no
Author(s):  
Yan-Ping Zhu ◽  
Mi Lian ◽  
Feng-Cheng Jia ◽  
Mei-Cai Liu ◽  
Jing-Jing Yuan ◽  
...  

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