Magnetically recoverable graphene-based nanocomposite material as an efficient catalyst for the synthesis of propargylamines via A3 coupling reaction

2017 ◽  
Vol 41 (21) ◽  
pp. 12756-12766 ◽  
Author(s):  
Najrul Hussain ◽  
Manash R. Das

The magnetically separable Au NPs–Fe3O4–rGO catalyst provides a robust and efficient route for the A3 coupling reaction of secondary amines, terminal alkynes and aldehyde with tolerance of diverse functional groups for the synthesis of propargylamine in high yields.

2021 ◽  
Vol 43 (1) ◽  
pp. 95-95
Author(s):  
Rifhat Bibi Rifhat Bibi ◽  
Muhammad Yaseen Muhammad Yaseen ◽  
Haseen Ahmad Haseen Ahmad ◽  
Ismat Ullah Khan Ismat Ullah Khan ◽  
Shaista Parveen Shaista Parveen ◽  
...  

Transition metals mediated cross coupling methodologies provide an extremely powerful versatile pathway in organic syntheses undoubtedly, a facile route for syntheses and derivatization of biologically important heterocycles from easily available precursors. Sonogashira coupling reaction, a leading method to Csp-Csp2 bond formation is one of the most important and rapid pathways to couple aryl/vinyl halides with terminal alkynes. Current research study deals with the synthesis of alkyne substituted quinoxaline derivatives. The quinoxalines class of aromatic heterocycles exhibits a wide variety of important biological potencies. Palladium catalyzed cross coupling process provided an effective synthetic practice for the synthesis of alkyne derivatives of quinoxaline. Vareity of terminal alkynes were coupled with 2-(4-bromophenyl)quinoxaline under optimized conditions for Sonogashira reaction, affording alkyne substituted quinoxaline derivatives in high yields. The optimized reaction conditions for coupling of range of terminal alkyne with quinoxaline basic core render this process significant for designing of medicinally interesting precursors.


2009 ◽  
Vol 62 (4) ◽  
pp. 353 ◽  
Author(s):  
Ji-Tai Li ◽  
Ming-Xuan Sun

The condensation of aromatic aldehydes and barbituric acid catalyzed by SiO2·12WO3·24H2O in aqueous media at room temperature gave 5-arylidene barbituric acid in high yields with or without the use of ultrasound, providing a simple and efficient route to synthesis of these compounds.


2015 ◽  
Vol 70 (3) ◽  
pp. 171-176 ◽  
Author(s):  
Shahrzad Abdolmohammadi ◽  
Maryam Afsharpour

AbstractA green, efficient and simple protocol was developed for the synthesis of dihydropyrimido[4,5-d]pyrimidinetrione derivatives via a coupling reaction of 6-aminouracils, aromatic aldehydes and urea in aqueous media in the presence of nano-crystalline CuI at room temperature. The products were obtained in high yields. CuI nanoparticles can be recycled three times without significant loss of catalytic activity.


Synthesis ◽  
2020 ◽  
Author(s):  
Nelson Luís C. Domingues ◽  
Beatriz F. dos Santos ◽  
Beatriz A. L. da Silva ◽  
Aline R. de Oliveira ◽  
Maria H. Sarragiotto ◽  
...  

AbstractA new and effective palladium catalyst supported on a magnesium organosilicate for application in the Heck reaction is presented. A group of compounds comprising 22 examples were synthesized in moderate to high yields (up to 99%) within a short time. The palladium supported on magnesium organosilicate catalyst was characterized as an amorphous solid by SEM, containing around 33% of palladium inside the solid, and even with this low quantity of palladium, the catalyst was very efficient in the Heck reaction. Besides, based on the Scherrer equation, the crystallite size of the synthesized palladium nanoparticles was ultrasmall (around 1.3 nm). This strategy is a simple and efficient route for the formation of C–C bonds via the Heck cross-coupling reaction.


2002 ◽  
Vol 2002 (11) ◽  
pp. 562-563 ◽  
Author(s):  
Xingliang Zheng ◽  
Yongmin Zhang

An efficient synthesis of biaryls from various aryl halides has been developed and investigated. The coupling reagent is a catalytic mixture of anhydrous NiCl2 and PPh3 in the presence of metallic samarium. The reaction occurs rapidly under mild conditions, tolerates a variety of functional groups with high yields.


2014 ◽  
Vol 989-994 ◽  
pp. 284-287 ◽  
Author(s):  
Ze Biao Tang ◽  
Xiao Xia Sun ◽  
Le Ping Miao ◽  
Hua Yin Shen

A novel electron donor unit based on phenothiazine has been designed and constructed. The target compound 10-octyl-3,7-di (thiophen-2-yl)-10H-phenothiazine was easily synthesized in high yields with a milder and efficient route via the Suzuki coupling reaction. Optical spectra show that, from the solution to the solid state, both the absorption and fluorescence spectra of the target compound are small blue-shifted. Moreover, the fluorescence spectra exhibit the emission maxima of the target compound ranging from 485 nm to 496 nm, which belongs to blue-green light region. As expected, the target compound should be a promising donor to construct D-A type materials for applications in organic light-emitting diodes (OLEDs).


2020 ◽  
Author(s):  
Dominique Forson ◽  
Xavier Verdaguer ◽  
Lluís Ribas de Pouplana ◽  
Antoni Riera ◽  
Enric Ros ◽  
...  

1,2,4,5-Tetrazines have become extremely useful tools in chemical biology. However, the synthesis of some challenging substrates such as 3,6-dialkyl-1,2,4,5-tetrazines is still a limitation for the widespread use of this class of compounds. Herein we describe an efficient route to these compounds based on the Sonogashira coupling of 3-bromo-6-methyl-1,2,4,5-tetrazine with terminal alkynes. The preparation of the starting reagent has been also optimized. The alkynyl products have been used as intermediates for the synthesis of dialkyl-tetrazines through a sequence of hydrogenation and re-oxidation with unprecedented yields. The synthetic applicability of this new approach is showcased through the preparation of several unnatural amino acids bearing alkynyl- and alkyl-1,2,4,5-tetrazine fragments.


2020 ◽  
Author(s):  
Dominique Forson ◽  
Xavier Verdaguer ◽  
Lluís Ribas de Pouplana ◽  
Antoni Riera ◽  
Enric Ros ◽  
...  

1,2,4,5-Tetrazines have become extremely useful tools in chemical biology. However, the synthesis of some challenging substrates such as 3,6-dialkyl-1,2,4,5-tetrazines is still a limitation for the widespread use of this class of compounds. Herein we describe an efficient route to these compounds based on the Sonogashira coupling of 3-bromo-6-methyl-1,2,4,5-tetrazine with terminal alkynes. The preparation of the starting reagent has been also optimized. The alkynyl products have been used as intermediates for the synthesis of dialkyl-tetrazines through a sequence of hydrogenation and re-oxidation with unprecedented yields. The synthetic applicability of this new approach is showcased through the preparation of several unnatural amino acids bearing alkynyl- and alkyl-1,2,4,5-tetrazine fragments.


2021 ◽  
Vol 43 (1) ◽  
pp. 95-95
Author(s):  
Rifhat Bibi Rifhat Bibi ◽  
Muhammad Yaseen Muhammad Yaseen ◽  
Haseen Ahmad Haseen Ahmad ◽  
Ismat Ullah Khan Ismat Ullah Khan ◽  
Shaista Parveen Shaista Parveen ◽  
...  

Transition metals mediated cross coupling methodologies provide an extremely powerful versatile pathway in organic syntheses undoubtedly, a facile route for syntheses and derivatization of biologically important heterocycles from easily available precursors. Sonogashira coupling reaction, a leading method to Csp-Csp2 bond formation is one of the most important and rapid pathways to couple aryl/vinyl halides with terminal alkynes. Current research study deals with the synthesis of alkyne substituted quinoxaline derivatives. The quinoxalines class of aromatic heterocycles exhibits a wide variety of important biological potencies. Palladium catalyzed cross coupling process provided an effective synthetic practice for the synthesis of alkyne derivatives of quinoxaline. Vareity of terminal alkynes were coupled with 2-(4-bromophenyl)quinoxaline under optimized conditions for Sonogashira reaction, affording alkyne substituted quinoxaline derivatives in high yields. The optimized reaction conditions for coupling of range of terminal alkyne with quinoxaline basic core render this process significant for designing of medicinally interesting precursors.


2021 ◽  
Vol 18 ◽  
Author(s):  
Dau Xuan Duc ◽  
Nguyen Van Quoc

: An efficient method for the Sonogashira coupling reaction between aryl halides and terminal alkynes has been developed. The reaction was performed in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) under microwave irradiation. High yields of products were obtained in very short reaction time. Moreover, the medium and catalyst could be recovered and reused three times without considerable decrease in reaction yields.


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