scholarly journals Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids

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.

2020 ◽  
Vol 74 (12) ◽  
pp. 4593-4598
Author(s):  
László Orha ◽  
Ábrahám Papp ◽  
József M. Tukacs ◽  
László Kollár ◽  
László T. Mika

Abstract The introduction of a biomass-derived ionic liquid into the Hiyama coupling reactions, which has been considered as a powerful tool for the synthesis of symmetrically and non-symmetrically substituted biaryl structures, could further control or even reduce the environmental impact of this transformation. It was shown that tetrabutylphosphonium 4-ethoxyvalerate, a γ-valerolactone-based ionic liquid, can be utilized as an alternative solvent to create carbon–carbon bonds between aryl iodides and functionalized organosilanes in the presence of 1 mol% Pd under typical Hiyama conditions (130 °C, 24 h, tetrabutylammonium fluoride activator). A comparison of different ionic liquids was performed, and the effects of the catalyst precursor and the moisture content of the reaction mixture on the activity of the catalyst system were investigated. The functional group tolerance was also studied, resulting in 15 cross-coupling products (3a–o) with isolated yields of 45–72% and excellent purity (> 98%).


2017 ◽  
Vol 41 (1) ◽  
pp. 372-376 ◽  
Author(s):  
Jinyi Song ◽  
Hongyan Zhao ◽  
Yang Liu ◽  
Huatao Han ◽  
Zhuofei Li ◽  
...  

A series of N,O-bidentate ligands were synthesized and studied as high activity ligands for palladium-catalyzed Suzuki–Miyaura cross-coupling reactions of aryl chlorides with arylboronic acids under mild conditions.


2010 ◽  
Vol 88 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jocelyn J. Tindale ◽  
Paul J. Ragogna

An ionic liquid, covalently tethered to an efficient transition-metal catalyst in the presence of an ionic liquid reaction medium, can utilize ionophilic interactions to improve catalyst activity, recyclability, and product isolation while decreasing catalyst leaching. Given the greater stability of phosphonium salts in comparison to imidazolium ionic liquids under basic conditions, phosphonium-tagged oxime carbopalladacycle salts were prepared and employed in both Heck and Suzuki–Miyaura reactions. The desired product was obtained in good yields for up to four catalyst cycles in the case of the Suzuki–Miyaura reaction. While taking advantage of the non-volatile nature of ionic liquids, the product was isolated through simple sublimation from the reaction mixture, eliminating issues associated with catalyst leaching, and the remaining ionic liquid solvent–catalyst mixture was ready for further catalysis.


RSC Advances ◽  
2015 ◽  
Vol 5 (24) ◽  
pp. 18960-18971 ◽  
Author(s):  
Gina M. Roberts ◽  
Wenya Lu ◽  
L. Keith Woo

Aqueous solutions of common and inexpensive surfactants (e.g. SDS and CTAB) are surveyed as an alternative to organic solvents in Sonogashira cross-coupling. Aryl-bromide substrates are best coupled under Cu-free conditions.


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