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Neat Water (neat + water)

Distribution by Scientific Domains

Chemistry	100%

Distribution within Chemistry

Organic Chemistry	57%
General & Introductory Chemistry	42%

Selected Abstracts

Insights into the Role of New Palladium Pincer Complexes as Robust and Recyclable Precatalysts for Suzuki,Miyaura Couplings in Neat Water

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009
Blanca Inés
Abstract Suzuki,Miyaura biaryl and diarylmethane syntheses via the coupling of arylboronic acids with aryl and arylmethyl bromides are performed in water by means of two new CNC-type palladium pincer complexes. Good to excellent results (including high TON values and extended recycling procedures) are obtained in most cases for a range of electronically dissimilar halides and boronic acids. On the basis of a series of kinetics studies, transmission electron microscopy (TEM), mercury drop tests, and quantitative poisoning experiments, the real role of the latter palladacycles, closely linked to the formation and active participation of palladium nanoparticles, is discussed. [source]

ChemInform Abstract: A Nonsymmetric Pincer-Type Palladium Catalyst in Suzuki, Sonogashira, and Hiyama Couplings in Neat Water.

CHEMINFORM, Issue 45 2008
Blanca Ines
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Heck Reaction Catalyzed by Palladacycle in Neat Water,

CHINESE JOURNAL OF CHEMISTRY, Issue 7 2003
Jian-Jun Hou
Abstract Cyclopalladated ferrocenylimine has been found to be a type of excellent phosphine-free catalyst for Heck reactions in neat water with both higher yields and turnover numbers than those reported in the literature up to now. Some commercial emulsifying agents, including the commonly used quaternary ammonium salts, have been proved to be excellent additives in the catalysis of the reactions. Not only aromatic iodide, but also aromatic bromide could be coupled with the olefins. All reactions were able to be conducted in air under refluxing condition. [source]

Hydroxypropyl-,-Cyclodextrin-Capped Palladium Nanoparticles: Active Scaffolds for Efficient Carbon-Carbon Bond Forming Cross-Couplings in Water

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009
Jaqueline
Abstract A new approach for the preparation of palladium nanoparticles in water from a renewable source, 2-hydroxypropyl-,-cyclodextrin (,-HPCD), which acts both as a reductant and capping agent, is presented. The palladium nanoparticles were characterized by using dynamic light scattering (DLS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), which revealed the formation of spherical particles in the size range of 2,7,nm. Further analysis by Fourier-transform infrared spectroscopy (FT-IR) and 1H,NMR did not show covalent bonds between cyclodextrins and palladium nanoparticles, suggesting that ,-HPCD is only physically adsorbed on the nanoparticle surface, presumably through hydrophobic interactions which limit the mutual coalescence of nanoclusters. The catalytic activity was tested in Suzuki, Heck and Sonogashira reactions in neat water, providing good yields and selectivities of coupling products under very low Pd loadings (0.5,0.01,mol%). Remarkably, the nanocatalyst showed significant stability hence the aqueous phase remained active for four subsequent runs. The combination of a binding site for substrates (the HPCD cavity) and a reactive centre (Pd core) provides a potential to explore functional catalysis in aqueous medium. [source]

A Mild, One-Pot Synthesis of Arylamines via Palladium- Catalyzed Addition of Aryl Aldehydes with Amines and Arylboronic Acids in Water

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009
Ajuan Yu
Abstract A mild, one-pot synthesis of diarylmethylamines via the palladium-catalyzed addition of aryl aldehydes with amines and arylboronic acids is reported. Best results were obtained in neat water with ammonium chloride as additive, affording diarylmethylamine derivatives as the main products. [source]

RhIII - and IrIII -Catalyzed Asymmetric Transfer Hydrogenation of Ketones in Water

CHEMISTRY - A EUROPEAN JOURNAL, Issue 7 2008
Xiaofeng Wu Dr.
Abstract Asymmetric transfer hydrogenation (ATH) of ketones by formate in neat water is shown to be viable with Rh-TsDPEN and Ir-TsDPEN catalysts, derived in situ from [Cp*MCl2]2 (M=Rh, Ir) and TsDPEN. A variety of ketones were reduced, including nonfunctionalized aryl ketones, heteroaryl ketones, ketoesters, and unsaturated ketones. In comparison with Ir-TsDPEN and the related RuII catalyst, the RhIII catalyst is most efficient in water, affording enantioselectivities of up to 99,% ee at substrate/catalyst (S/C) ratios of 100,1000 even without working under an inert atmosphere. The aqueous phase reduction is shown to be highly pH-dependent; the optimum pH windows for TOF greater than 50,mol,mol,1,h,1 for Rh- and Ir-TsDPEN are 5.5,10.0 and 6.5,8.5, respectively. Outside the pH window, the reduction becomes slow or stagnant depending on the pH. However, the enantioselectivities erode only under acidic conditions. At a higher S/C ratio, the aqueous ATH by Rh-TsDPEN is shown to be product- as well as byproduct-inhibited; the product inhibition appears to stem at least partly from the reaction being reversible. The aqueous phase reduction is simple, efficient and environmentally benign, thus presenting a viable alternative for asymmetric reduction. [source]