scholarly journals Surfactant Micelles Enable Metal-Free Spirocyclization of Keto-Ynamides and Access to Aza-Spiro Scaffolds in Aqueous Media

2019 ◽  
Vol 2019 (41) ◽  
pp. 6989-6993
Author(s):  
Frédéric Beltran ◽  
Andrea V. Vela-Gonzalez ◽  
Tatiana Knaub ◽  
Marc Schmutz ◽  
Marie Pierre Krafft ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Surfactant Micelles ◽  
Metal Free

Dissociation of imino proton(s) of a highly water-soluble metal-free phthalocyanine and determination of its pKa value in water

2013 ◽  
Vol 17 (06n07) ◽  
pp. 447-453 ◽  
Author(s):  
Hiroaki Isago ◽  
Harumi Fujita
Keyword(s):  
Aqueous Media ◽  
Thermal Reaction ◽  
Water Soluble ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Metal Free ◽  
Imino Proton ◽  
Pka Value ◽  
Triton X

Dissociation of imino proton(s) in the cavity of the macrocycle of a highly water-soluble, metal-free phthalocyanine ( H 2( H 4 tsppc ); where H 4 tsppc denotes tetrakis{(2′,6′-dimethyl-4′-sulfonic acid)phenoxy}phthalocyaninate) in ethanolic and aqueous solutions has spectrophotometrically been investigated. The spectral changes associated with reaction with NaOH have been found to involve one-proton transfer process in aqueous media while two-protons process in ethanolic media. The acid-dissociation constant of the first imino proton in water (in the presence of Triton X-100) has been determined to be 12.5 ± 0.2 (as pKa) at 25 °C. The doubly deprotonated species in EtOH has been easily converted to its corresponding cobalt(II) derivative by thermal reaction with anhydrous CoCl 2.

New metal-free catalytic degradation systems with carbon dots for thymol blue

2017 ◽  
Vol 41 (22) ◽  
pp. 13365-13369 ◽  
Author(s):  
Cui Zheng ◽  
Xueqin An ◽  
Tianxiang Yin
Keyword(s):  
Catalytic System ◽  
Carbon Dots ◽  
Aqueous Media ◽  
Catalytic Degradation ◽  
Thymol Blue ◽  
Metal Free

A metal-free catalytic system with carbon dots as a catalyst for thymol blue degradation in slightly alkaline aqueous media.

Synthesis of 2,3-Dihydrotryptamines from Amide Solvents and Acyclic Materials through Metal-Free Amidoalkylarylation of Unactivated Alkenes

Synlett ◽  
2019 ◽  
Vol 30 (11) ◽  
pp. 1329-1333
Author(s):  
Yubin Ji ◽  
Siping Yang ◽  
Shiyi Lin ◽  
Yan Wang ◽  
Chenfeng Ji ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Metal Free ◽  
Simple Operation ◽  
Reaction Proceeds

The first synthesis of 2,3-dihydrotryptamines from acyclic materials and an exo-selective amidoalkylation/cyclization cascade of N-allyl anilines through α-C(sp3)–H functionalization of simple amides across unactivated alkenes are presented. This reaction proceeds in mixed aqueous media and under metal-free conditions and features a broad substrate scope and a simple operation.

scholarly journals Transition‐Metal‐Free Direct C‐H Arylation of Thiophene in Aqueous Media via Potassium Peroxymonosulfate

2019 ◽  
Vol 4 (29) ◽  
pp. 8516-8521
Author(s):  
Sezer Özenler ◽  
Hakan Kaya ◽  
Nuran Elmaci ◽  
Umit Hakan Yildiz
Keyword(s):  
Transition Metal ◽  
Aqueous Media ◽  
Metal Free ◽  
Potassium Peroxymonosulfate

Direct C-3 alkylation of coumarins via decarboxylative coupling with carboxylic acids

2019 ◽  
Vol 43 (24) ◽  
pp. 9328-9332 ◽  
Author(s):  
Farnaz Jafarpour ◽  
Masoumeh Darvishmolla ◽  
Narges Azaddoost ◽  
Farid Mohaghegh
Keyword(s):  
Carboxylic Acids ◽  
Aqueous Media ◽  
Metal Free ◽  
Decarboxylative Coupling

A metal-free direct alkylation of coumarins using carboxylic acids in aqueous media with a broad substrate scope is devised.

Sorption of chlormequat on montmorillonite as affected by dissolved copper. Influence of background electrolytes

Clay Minerals ◽  
2001 ◽  
Vol 36 (4) ◽  
pp. 473-481 ◽  
Author(s):  
C. Maqueda ◽  
E. Morillo
Keyword(s):  
Heavy Metal ◽  
Exchange Process ◽  
Aqueous Media ◽  
Background Electrolyte ◽  
Inorganic Cations ◽  
Metal Free ◽  
Free Treatment ◽  
Cationic Exchange ◽  
Background Electrolytes

AbstractIn this paper, the role of Cu in the adsorption of the cationic pesticide chlormequat (CCC) on montmorillonite is studied. The adsorption of CCC was measured in various media, e.g. water and aqueous solutions of NaCl, CaCl2 and Ca(NO3)2 at the same ionic strength (I= 0.01 mol l–1). The retention of CCC on montmorillonite in aqueous media is due principally to a cationic exchange process with inorganic cations which saturate the interlamellar positions on this mineral. However, the amount of inorganic cations liberated from montmorillonite was ∼15% less than the amount of CCC adsorbed. This indicates that not all the pesticide was adsorbed through cation exchange.The adsorption of CCC in aqueous media decreased in the presence of a heavy metal, compared with metal-free treatment. This behaviour indicates competition between the two cations for interlamellar positions. The adsorption of CCC in the presence of Cu also decreased in electrolyte media with the effect being highest in the presence of Ca electrolytes. The maximum CCC diminution was ∼30%. However, the isotherms derived in CaCl2 and Ca(NO3)2 media at different Cu concentrations were close to each other, indicating that Ca from background electrolyte exerts greater competition than Cu for montmorillonite planar positions.

ChemInform Abstract: Metal-Free, One-Pot Oxidative Conversion of Aldehydes to Primary Thioamides in Aqueous Media

ChemInform ◽  
2014 ◽  
Vol 45 (23) ◽  
pp. no-no
Author(s):  
Arvind K. Yadav ◽  
Vishnu P. Srivastava ◽  
Lal Dhar S. Yadav
Keyword(s):  
Aqueous Media ◽  
Oxidative Conversion ◽  
One Pot ◽  
Metal Free
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