scholarly journals Friedel–Crafts-Type Alkylation of Indoles in Water Using Amphiphilic Resin-Supported 1,10-Phenanthroline–Palladium Complex under Aerobic Conditions

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 193
Author(s):  
Toshimasa Suzuka ◽  
Yuto Ooshiro ◽  
Kazuhito Ogihara
Keyword(s):  
High Selectivity ◽  
Palladium Complex ◽  
Palladium Complexes ◽  
High Yield ◽  
Alkylation Reaction ◽  
Poly Ethylene Glycol ◽  
Aerobic Conditions ◽  
Palladium Catalyzed ◽  
Poly Ethylene ◽  
Polymeric Catalyst

The palladium-catalyzed Friedel-Crafts-type alkylation of indoles in water has been achieved using amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported phenanthroline-palladium complexes in water under aerobic conditions, affording the corresponding products with good-to-high yield. The polymeric catalyst was also found to promote the C3-alkylation reaction to give a thermodynamic alkylation product with high selectivity. The polymeric catalyst was recovered and reused several times without any loss of catalytic activity.

PEG1000 as a Low Melting and Ecofriendly Solvent for Air Oxidative and Catalyst Free 2,4-Disubstitute Quinazoline Synthesis

2020 ◽  
Vol 17 (9) ◽  
pp. 709-716
Author(s):  
Ebrahim Saeedian Moghadam ◽  
Shahrzad Ghafary ◽  
Mohsen Amini
Keyword(s):  
Melting Point ◽  
High Yield ◽  
Purification Process ◽  
Poly Ethylene Glycol ◽  
Free Condition ◽  
Catalyst Free ◽  
Privileged Scaffold ◽  
Quinazoline Derivatives ◽  
Poly Ethylene ◽  
Work Up

With regard to the importance of quinazoline as a privileged scaffold, herein we report the synthesis of twenty seven 2,4-disubstitute quinazoline derivatives in a new catalyst free condition. In the current work, poly ethylene glycol (PEG1000) as an inexpensive, very simple commercially available, ecofriendly and low melting point solvent was used. Air bubbling, a green oxidant, for oxidation purpose was also used. This is the first report about using PEG1000 as a solvent simultaneously with air bubbling as oxidant in quinazoline synthesis. All of the compounds 1-27 were synthesized in high yield with very simple work up and purification process without using column chromatography. All the structures were confirmed using 1H NMR, 13C NMR, IR, MS and elemental analysis.

N-Heterocyclic Carbene Conjugated with Poly(ethylene glycol) for Palladium-Catalyzed Suzuki–Miyaura Coupling in Aqueous Solvents

2013 ◽  
Vol 144 (1) ◽  
pp. 158-164 ◽  
Author(s):  
Ji-cheng Shi ◽  
Hongwei Yu ◽  
Dahong Jiang ◽  
Mei Yu ◽  
Yanxian Huang ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Palladium Catalyzed ◽  
Poly Ethylene

The improvement of lipase secretion and stability by addition of inert compounds into Acinetobacter calcoaceticus cultures

2002 ◽  
Vol 48 (12) ◽  
pp. 1056-1061 ◽  
Author(s):  
Daniela A Martinez ◽  
B Clara Nudel
Keyword(s):  
Enzyme Activity ◽  
Gum Arabic ◽  
Acinetobacter Calcoaceticus ◽  
Glass Beads ◽  
High Yield ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Cell Fractions ◽  
Triton X ◽  
Effective Additive

Acinetobacter calcoaceticus BD413 produces variable amounts of an exocellular lipase that becomes rapidly inactivated upon secretion. To achieve high yield and protect the enzyme, we assayed the addition of several inert compounds to cell-free supernatants, cell fractions, and whole cultures. Glass beads, poly(ethylene glycol) 600, Triton X-100, saccharose, gum arabic, and β-cyclodextrin were among the compounds tested. β-Cyclodextrin and gum arabic (and saccharose to a lesser extent) were effective enzyme stabilizers in cell-free supernatants, while gum arabic, glass beads, and Triton X-100 improved lipase secretion from cells, and, therefore, total lipase yield (30–50%, according to the additive). In whole cultures, β-cyclodextrin was the most effective additive, particularly in combination with glass beads or gum arabic. Indeed, cultures containing β-cyclodextrin plus gum arabic were able to maintain 95% (±1.5%) of the initial lipase activity for more than 16 h, while control cultures with no additives maintained only 10% (±4%) of the enzyme activity after the same period. In conclusion, the addition of inert compounds in cultures may be considered a useful approach for achieving increased yield and lipase stabilization, amenable for downstream processing.Key words: Acinetobacter calcoaceticus, lipase, secretion, stabilization, inert additives.

Asymmetric allylic substitution of cycloalkenyl esters in water with an amphiphilic resin-supported chiral palladium complex

2007 ◽  
Vol 79 (9) ◽  
pp. 1481-1489 ◽  
Author(s):  
Yasuhiro Uozumi
Keyword(s):  
Ethylene Glycol ◽  
Palladium Complex ◽  
Reaction Medium ◽  
Optically Active ◽  
Racemic Mixture ◽  
Poly Ethylene Glycol ◽  
Supported Palladium ◽  
Poly Ethylene ◽  
Phosphine Complex ◽  
Single Reaction

A novel homochiral phosphine ligand, (3R,9aS)[2-aryl-3-(2-diphenylphosphino)phenyl]tetrahydro-1H-imidazo[1,5-a]indole-1-one, was designed, prepared, and anchored onto an amphiphilic polystyrene-poly(ethylene glycol) copolymer (PS-PEG) resin. Catalytic asymmetric substitution of a racemic mixture of cycloalkenyl esters with carbon, nitrogen, and oxygen nucleophiles was achieved in water as the single reaction medium under heterogeneous conditions by using the PS-PEG resin-supported palladium-imidazoindole phosphine complex to give optically active substituted cycloalkenes with up to 99 % ee.

Bulky α-diimine palladium complexes: highly efficient for direct C–H bond arylation of heteroarenes under aerobic conditions

2016 ◽  
Vol 45 (38) ◽  
pp. 14919-14927 ◽  
Author(s):  
Jia-Sheng Ouyang ◽  
Yan-Fang Li ◽  
Dong-Sheng Shen ◽  
Zhuofeng Ke ◽  
Feng-Shou Liu
Keyword(s):  
Palladium Complex ◽  
Palladium Complexes ◽  
Aerobic Conditions ◽  
Highly Efficient

Through the strategy to enhance the bulkiness on both the backbone and the N-aryl moieties, we designed and synthesized a type of bulky α-diimine palladium complex (i.e., {[Ar–NC(R)–C(R)N–Ar]PdCl2, (Ar = 2-benzhydryl-4,6-dimethylphenyl)}, C1, R = H; C2, R = An; C3, R = Ph).

Poly(ethylene glycol): an Alternative Solvent for the Synthesis of Cyclic Carbonate from Vicinal Halohydrin and Carbon Dioxide

2009 ◽  
Vol 62 (8) ◽  
pp. 917 ◽  
Author(s):  
Jing-Lun Wang ◽  
Liang-Nian He ◽  
Xiao-Yong Dou ◽  
Fang Wu
Keyword(s):  
Carbon Dioxide ◽  
Ethylene Glycol ◽  
Reaction Medium ◽  
Cyclic Carbonate ◽  
High Yield ◽  
Cyclic Carbonates ◽  
Poly Ethylene Glycol ◽  
Potential Applications ◽  
Ready Availability ◽  
Poly Ethylene

Poly(ethylene glycol) (PEG) in this work proved to be an efficient reaction medium for the reaction of vicinal halohydrin with carbon dioxide in the presence of a base to synthesise cyclic carbonates. Notably, PEG-400 as an environmentally friendly solvent exhibits a unique influence on reactivity compared with conventional organic solvents. Various cyclic carbonates were prepared in high yield employing this protocol. The process presented here has potential applications in the industrial production of cyclic carbonates because of its simplicity, cost benefits, ready availability of starting materials, and mild reaction conditions.

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