scholarly journals Synthesis of Polyfunctionalized 4H-Pyrans

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Manisha Bihani ◽  
Pranjal P. Bora ◽  
Ghanashyam Bez

Amberlyst A21 catalyzed one-pot three-component coupling of aldehyde and malononitrile with active methylene compounds such as acetylacetone and ethyl acetoacetate for the synthesis of pharmaceutically important polyfunctionalized 4H-pyrans has been reported. Simple experimental procedure, no chromatographic purification, no hazardous organic solvents, easy recovery and reusability of the catalyst, and room temperature reaction conditions are some of the highlights of this protocol for the synthesis of pharmaceutically relevant focused libraries.

2020 ◽  
pp. 174751982096418
Author(s):  
Ting-Ting Liu ◽  
Jiao-Zhao Yan ◽  
Xin-Wang Cheng ◽  
Pan Duan ◽  
Yao-Fu Zeng

A one-pot method for the synthesis of azo compounds by the reaction of β-naphthol with aryl amines using t-BuONO as the nitrosonium source in DCM at room temperature was developed. This method features mild reaction conditions, a simple experimental procedure, and is free of acidic or alkaline additives.


2015 ◽  
Vol 5 (3) ◽  
pp. 1623-1628 ◽  
Author(s):  
Dengke Wang ◽  
Zhaohui Li

Bi-functional NH2-MIL-101(Fe) can efficiently catalyze the one-pot reaction between aromatic alcohols and active methylene compounds via a tandem photo-oxidation/Knoevenagel condensation under visible light and at room temperature.


2018 ◽  
Vol 15 (3) ◽  
pp. 380-387
Author(s):  
Xia Zhao ◽  
Xiaoyu Lu ◽  
Lipeng Zhang ◽  
Tianjiao Li ◽  
Kui Lu

Aim and Objective: Pyrazolone sulfones have been reported to exhibit herbicidal and antibacterial activities. In spite of their good bioactivities, only a few methods have been developed to prepare pyrazolone sulfones. However, the substrate scope of these methods is limited. Moreover, the direct sulfonylation of pyrazolone by aryl sulfonyl chloride failed to give pyrazolone sulfones. Thus, developing a more efficient method to synthesize pyrazolone sulfones is very important. Materials and Method: Pyrazolone, aryl sulphonyl hydrazide, iodine, p-toluenesulphonic acid and water were mixed in a sealed tube, which was heated to 100°C for 12 hours. The mixture was cooled to 0°C and m-CPBA was added in batches. The mixture was allowed to stir for 30 min at room temperature. The crude product was purified by silica gel column chromatography to afford sulfuryl pyrazolone. Results: In all cases, the sulfenylation products were formed smoothly under the optimized reaction conditions, and were then oxidized to the corresponding sulfones in good yields by 3-chloroperoxybenzoic acid (m-CPBA) in water. Single crystal X-ray analysis of pyrazolone sulfone 4aa showed that the major tautomer of pyrazolone sulfones was the amide form instead of the enol form observed for pyrazolone thioethers. Moreover, the C=N double bond isomerized to form an α,β-unsaturated C=C double bond. Conclusion: An efficient method to synthesize pyrazolone thioethers by iodine-catalyzed sulfenylation of pyrazolones with aryl sulfonyl hydrazides in water was developed. Moreover, this method was employed to synthesize pyrazolone sulfones in one-pot by subsequent sulfenylation and oxidation reactions.


2015 ◽  
Vol 39 (7) ◽  
pp. 5350-5353 ◽  
Author(s):  
Subhash Banerjee

A simple and efficient protocol for selective bis-Michael addition and mono-allylation of active methylene compounds has been demonstrated using ultra-small size (∼5 nm) uncapped cerium oxide nanoparticles (free-CeO2 NPs) as a reusable catalyst in water at room temperature.


2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Abdullah Mohamed Asiri ◽  
Afaf Mohamed Abdel Hameed ◽  
Reham R. Awed ◽  
Kamal Usef Sadek

AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.


2014 ◽  
Vol 636 ◽  
pp. 93-96
Author(s):  
Ming Zhang ◽  
Wen Shuai Zhu ◽  
Meng Li ◽  
Yan An Li ◽  
Suhang Xun ◽  
...  

Tungsten-containing functional mesoporousW-SiO2 have been successfully synthesized by an one-pot and facile room-temperature procedure. These materials presented a high dispersion of tungsten species and excellent catalytic activity on the removal of sulfur compounds without any organic solvents as extractants. The catalytic performance on sulfur compounds was investigated in detail. After recycling for 8 times, the removal of the oxidation desulfurization system could still reach 92.0%.


Synthesis ◽  
2019 ◽  
Vol 52 (05) ◽  
pp. 744-754
Author(s):  
Yoona Song ◽  
Soyun Lee ◽  
Palash Dutta ◽  
Jae-Sang Ryu

A copper(I)-mediated tandem three-component reaction using alkynes, azides, allyl iodides, CuI and NaNH2 is developed. The reactions proceed smoothly at room temperature to afford 5-allyl-1,2,3-triazoles, which can be further converted into 1,2,3-triazole-fused tricyclic scaffolds. This method features an efficient one-pot cascade route using commercial alkynes and affords the corresponding 5-allyl-1,2,3-triazoles with high yields and good selectivity under mild reaction conditions.


Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 522-529 ◽  
Author(s):  
Deqing Shi ◽  
Lingna Wang ◽  
Tiancong Ma ◽  
Mingming Qiao ◽  
Qiangxian Wu ◽  
...  

A visible-light photoredox-catalyzed oxidation/[3+2] cycloaddition/oxidative aromatization cascade reaction of [(3,4-dihydroisoquinolin-2(1H)-yl)methyl]phosphonates and activated olefins or alkynes for the efficient synthesis of potentially biological active pyrrolo[2,1-a]isoquinoline-substituted phosphonates was developed. This transformation features mild reaction conditions (i.e., visible light irradiation, room temperature), molecular oxygen (O2) as a green oxidant, simple ‘one-pot’ operation.


Sign in / Sign up

Export Citation Format

Share Document