Glycerol: A Promising Benign Solvent for Catalyst Free One-Pot Multi-Component Synthesis of Pyrano[2,3-c]pyrazoles and Tetrahydro-benzo[b]pyrans at Ambient Temperature

2017 ◽  
Vol 2 (33) ◽  
pp. 10689-10693 ◽  
Author(s):  
Afaf Abdel Hamid ◽  
Mohamed Abd-Elmonem ◽  
Alaa M. Hayallah ◽  
Fatma A. Abo Elsoud ◽  
Kamal U. Sadek
RSC Advances ◽  
2019 ◽  
Vol 9 (53) ◽  
pp. 30768-30772 ◽  
Author(s):  
Mandlenkosi Robert Khumalo ◽  
Surya Narayana Maddila ◽  
Suresh Maddila ◽  
Sreekantha B. Jonnalagadda

A facile, swift and ecofriendly microwave-assisted multi-component/one-pot protocol is designed for the synthesis of novel pyrazolo-[3,4-b]-quinolines at ambient temperature in aqueous ethanol as a reaction medium.


2020 ◽  
Author(s):  
José Tiago Menezes Correia ◽  
Gustavo Piva da Silva ◽  
Camila Menezes Kisukuri ◽  
Elias André ◽  
Bruno Pires ◽  
...  

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.


2018 ◽  
Vol 21 (4) ◽  
pp. 302-311
Author(s):  
Younes Ghalandarzehi ◽  
Mehdi Shahraki ◽  
Sayyed M. Habibi-Khorassani

Aim & Scope: The synthesis of highly substituted piperidine from the one-pot reaction between aromatic aldehydes, anilines and β-ketoesters in the presence of tartaric acid as a catalyst has been investigated in both methanol and ethanol media at ambient temperature. Different conditions of temperature and solvent were employed for calculating the thermodynamic parameters and obtaining an experimental approach to the kinetics and mechanism. Experiments were carried out under different temperature and solvent conditions. Material and Methods: Products were characterized by comparison of physical data with authentic samples and spectroscopic data (IR and NMR). Rate constants are presented as an average of several kinetic runs (at least 6-10) and are reproducible within ± 3%. The overall rate of reaction is followed by monitoring the absorbance changes of the products versus time on a Varian (Model Cary Bio- 300) UV-vis spectrophotometer with a 10 mm light-path cell. Results: The best result was achieved in the presence of 0.075 g (0.1 M) of catalyst and 5 mL methanol at ambient temperature. When the reaction was carried out under solvent-free conditions, the product was obtained in a moderate yield (25%). Methanol was optimized as a desirable solvent in the synthesis of piperidine, nevertheless, ethanol in a kinetic investigation had none effect on the enhancement of the reaction rate than methanol. Based on the spectral data, the overall order of the reaction followed the second order kinetics. The results showed that the first step of the reaction mechanism is a rate determining step. Conclusion: The use of tartaric acid has many advantages such as mild reaction conditions, simple and readily available precursors and inexpensive catalyst. The proposed mechanism was confirmed by experimental results and a steady state approximation.


2020 ◽  
Vol 17 ◽  
Author(s):  
Visarapu Malathi ◽  
Pedavenkatagari Narayana Reddy ◽  
Pannala Padmaja

Abstract:: An efficient method has been developed for the synthesis of new pyrano[3,2-c] and pyrano[3,2-a]carbazole de-rivatives via a three component reaction of 4-hydroxycarbazole or 2-hydroxycarbazole, isocyanides, and dialkylacetylenedi-carboxylates. Noteworthy features of this protocol include mild reaction conditions, catalyst-free, high atom-economy and high yields.


2021 ◽  
Vol 45 (14) ◽  
pp. 6367-6378
Author(s):  
Bhanwar Kumar Malviya ◽  
Karandeep Singh ◽  
Pradeep K. Jaiswal ◽  
Manvika Karnatak ◽  
Ved Prakash Verma ◽  
...  

One pot metal-free synthesis of phenanthridines and amides under electrochemical conditions.


Author(s):  
Xing Li ◽  
Pingan Zhai ◽  
Yongsheng Fang ◽  
Wenhui Li ◽  
Honghong Chang ◽  
...  

A general and practical strategy for the construction of various keto-substituted isoxazolidines via one-pot three-component reaction of easily accessible, safer and more stable sulfoxonium ylides, nitrosoarenes and olefins is described.


2021 ◽  
Vol 33 ◽  
pp. 100693
Author(s):  
Visarapu Malathi ◽  
Shantholla Shivani ◽  
K Bhaskar ◽  
Vinod G. Ugale ◽  
Pannala Padmaja ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 41 (44) ◽  
pp. no-no
Author(s):  
Gowravaram Sabitha ◽  
N. Mallikarjuna Reddy ◽  
M. Nagendra Prasad ◽  
G. S. K. Raja ◽  
J. S. Yadav

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1589-1592 ◽  
Author(s):  
Abolfazl Olyaei ◽  
Mahnaz Saraei ◽  
Reyhaneh Khoeiniha

A high-yielding cyclocondensation of 4-hydroxycoumarin, phenylglyoxal monohydrate, and heteroarylamines proceeds without catalysis, which gives novel functionalized furo[3,2-c]coumarins and heteroarylamino alkylation of coumarin products in acetonitrile under reflux, is reported for the first time. This tandem process involves sequentially an aldol condensation, Michael addition, a ring closure, and dehydration reaction.


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