scholarly journals The effects of amines on oxidative homo-coupling of terminal alkynes promoted by copper salts

2005 ◽  
Vol 2005 (2) ◽  
pp. 112-115 ◽  
Author(s):  
Lei Wang ◽  
Jincan Yan ◽  
Pinhua Li ◽  
Min Wang ◽  
Caina Su

The effects of all kinds of amines on homo-couplings (Glaser reactions) of terminal alkynes promoted by copper salts and the Sonogashira coupling reactions were studied systematically. Diethylamine (2° amine) can serve as an excellent solvent, base and coordination ligand in the oxidative homo-coupling of terminal alkynes and several modified Glaser coupling procedures have been developed which are based on a catalytic amount of cuprous salts (CuI, CuBr or CuCl) with diethylamine systems. Homo-coupling of terminal acetylenes in the Sonogashira reaction could be inhibited by using triethylamine (3° amine) as reaction medium, and the cross-coupling products were formed as the exclusive products.

2019 ◽  
Vol 15 ◽  
pp. 2907-2913 ◽  
Author(s):  
László Orha ◽  
József M Tukacs ◽  
László Kollár ◽  
László T Mika

It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.


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.


2018 ◽  
Vol 14 ◽  
pp. 1871-1884 ◽  
Author(s):  
Siva Sankar Murthy Bandaru ◽  
Darinka Dzubiel ◽  
Heiko Ihmels ◽  
Mohebodin Karbasiyoun ◽  
Mohamed M A Mahmoud ◽  
...  

9-Arylbenzo[b]quinolizinium derivatives were prepared with base-free Suzuki–Miyaura coupling reactions between benzo[b]quinolizinium-9-trifluoroborate and selected benzenediazonium salts. In addition, the Sonogashira coupling reaction between 9-iodobenzo[b]quinolizinium and the arylalkyne derivatives yielded four novel 9-(arylethynyl)benzo[b]quinolizinium derivatives under relatively mild reaction conditions. The 9-(N,N-dimethylaminophenylethynyl)benzo[b]quinolizinium is only very weakly emitting, but the emission intensity increases by a factor >200 upon protonation, so that this derivative may operate as pH-sensitive light-up probe. Photometric and fluorimetric titrations of duplex and quadruplex DNA to 9-(arylethynyl)benzo[b]quinolizinium derivatives revealed a significant binding affinity of these compounds towards both DNA forms with binding constants ofKb= 0.2–2.2 × 105M−1.


Author(s):  
Varshini Jayantha Kumar ◽  
Jian-Zhong Wu ◽  
Martyna Judd ◽  
Elodie ROUSSET ◽  
Marcus Korb ◽  
...  

A series of 6-oxo verdazyl radicals functionalised at the 1- and 5-positions by methyl, thiomethyl and iodo groups were synthesised using conventional strategies. Facile Sonogashira cross-coupling reactions of terminal alkynes...


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3292 ◽  
Author(s):  
Kazuki Komoda ◽  
Rei Iwamoto ◽  
Masakazu Kasumi ◽  
Hideki Amii

A convenient and effective route for the synthesis of aryl(difluoromethyl)phosphonates has been developed based on cross-coupling reactions. Upon treatment with a stoichiometric amount (or a catalytic amount in some cases) of CuI and CsF, aryl iodides reacted smoothly with (silyldifluoromethyl)phosphonates to give the corresponding aryl(difluoromethyl)phosphonates in good yields.


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