ChemInform Abstract: Water-Soluble Calixarenes as New Inverse Phase-Transfer Catalysts. Nucleophilic Substitution of Alkyl and Arylalkyl Halides in Aqueous Media.

ChemInform ◽  
2010 ◽  
Vol 29 (1) ◽  
pp. no-no
Author(s):  
S. SHIMIZU ◽  
K. KITO ◽  
Y. SASAKI ◽  
C. HIRAI
Keyword(s):  
Nucleophilic Substitution ◽  
Phase Transfer ◽  
Aqueous Media ◽  
Water Soluble ◽  
Phase Transfer Catalysts

Novel lariat calix[4]-1,3-aza-crowns with two branched chains — The excellent phase transfer catalysts for nucleophilic substitution reaction

2010 ◽  
Vol 88 (7) ◽  
pp. 622-627 ◽  
Author(s):  
Fafu Yang ◽  
Yanhua Wang ◽  
Hongyu Guo ◽  
Jianwei Xie ◽  
Zhiqiang Liu
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reaction ◽  
Phase Transfer ◽  
Hard Metal ◽  
Nucleophilic Substitution Reaction ◽  
Phenyl Isothiocyanate ◽  
Phase Transfer Catalysts ◽  
H Nmr ◽  
Branched Chains ◽  
New Compounds

By reacting calix[4]-1,3-diethoxylaminoethyl derivative (2) with phenyl isothiocyanate, novel dendritic calix[4]arene derivative (3) with two different branched chains was synthesized in a yield of 78%. By reacting compound 2 with 1,6-diisocyanatohexane or N,N′-bis(2-chloracetamide)ethylene in a “1 + 1” intermolecular addition mode, novel lariat calix[4]-1,3-aza-crowns (4 and 5, respectively) with two branched ethoxyl chains were prepared in reasonable yields. The composition, structures, and conformations of all new compounds were confirmed by elemental analyses, IR, ESI-MS, 1H NMR, and so forth. The liquid–liquid extraction experiments showed that all new hosts possessed good extraction abilities towards soft and hard metal cations. The liquid membrane transport experiments suggested that they had good transport abilities for K+ and Ag+. The experiments of phase transfer catalysis indicated that they possessed excellent catalytic properties of aromatic nucleophilic substitution reaction and benzyl nucleophilic substitution. The optimum yields of products in catalytic reaction were as high as approximately 100%.

Microwave-Assisted Chemistry: a Rapid and Sustainable Route to Synthesis of Organics and Nanomaterials

2009 ◽  
Vol 62 (1) ◽  
pp. 16 ◽  
Author(s):  
Vivek Polshettiwar ◽  
Mallikarjuna N. Nadagouda ◽  
Rajender S. Varma
Keyword(s):  
Nucleophilic Substitution ◽  
Phase Transfer ◽  
Aqueous Media ◽  
Primary Amines ◽  
Poly Vinyl Alcohol ◽  
Chemical Transformations ◽  
Chemical Waste ◽  
Uniform Size ◽  
Solvent Free Conditions ◽  
Shape Controlled

The use of emerging microwave (MW)-assisted chemistry techniques in conjunction with benign reaction media is dramatically reducing chemical waste and reaction times in several organic syntheses and chemical transformations. The present review summarizes recent developments in MW-assisted synthesis, name reactions and organic transformations, and rapid generation of nanoparticles with uniform size distribution. Greener protocols have been developed for the synthesis of various bio-active heterocycles, namely 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, 1,3-dioxanes, pyrazoles, hydrazones and 3,4-dihydropyrimidin-2(1H)-ones, which proceed under the influence of microwaves and using eco-friendly conditions. These high-yielding methods were catalyzed efficiently by solid-supported Nafion NR50 under solvent-free conditions and polystyrene sulfonic acid in aqueous media. The eco-friendly nucleophilic substitution chemistry in water to generate cyclic amines via double N-alkylation of primary amines or hydrazines by dihalides or tosylates enables the greener synthesis of a range of pharmaceutically active heterocycles. Similarly, efficient MW synthesis of various azides, thiocyanates, and sulfones in aqueous medium occurs wherein nucleophilic substitution reaction takes place in the absence of a phase-transfer catalyst. Bulk and shape-controlled synthesis of noble nanostructures via MW-assisted spontaneous reduction of noble metal salts using α-d-glucose, sucrose, and maltose is described. MW method also accomplishes the cross-linking reaction of poly(vinyl alcohol) with metallic systems such as Pt, Cu, and In; bimetallic systems, namely Pt–In, Ag–Pt, Pt–Fe, Cu–Pd, Pt–Pd, and Pd–Fe; and single-walled nanotubes, multi-walled nanotubes, and buckminsterfullerenes (C-60). The strategy is extended to the formation of biodegradable carboxymethyl cellulose (CMC) composite films with noble nanometals; such metal decoration and alignment of carbon nanotubes in CMC is possible using a MW approach that also enables the shape-controlled bulk synthesis of Ag and Fe nanorods in poly(ethylene glycol).

ChemInform Abstract: Water-Soluble Calixarenes as New Inverse Phase-Transfer Catalysts. Their Scope in Aqueous Biphasic Alkylations and Mechanistic Implications.

ChemInform ◽  
2010 ◽  
Vol 33 (42) ◽  
pp. no-no
Author(s):  
Shoichi Shimizu ◽  
Takashi Suzuki ◽  
Seiji Shirakawa ◽  
Yasuyuki Sasaki ◽  
Choichiro Hirai
Keyword(s):  
Phase Transfer ◽  
Water Soluble ◽  
Phase Transfer Catalysts ◽  
Aqueous Biphasic
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