Catalytic reagents

Dehydrochlorination 1,1,2-Trichloroethane is easily dehydrochloriaated by a number of catalytic reagents to give 1,1-dichloroethylene and some 1,2-dichloroethylene. Refluxing with aqueous and methanolic solutions of NaOH, Ca(OH)2, and Mg(OH)2 and water gives 1,1-dichloroethylene... 

Organomercurial carbonylation. Use of Co2(CO)g as a stoichiometric and as a catalytic reagent Organic synthesis reactions using palladium compounds Decarbonylation reactions using transition metal compounds... 

Catalytic reagents (as selective as possible) are superior to stoichiometric reagents. 

Greg Fu supervised the proofreading and provided the structural formula based on the x-ray data for the new Sharpless catalytic reagent for osmylation of alkenes. Martita F. Barsotti is the photographer for the picture of some present and former co-workers for Reagents. 

As mentioned in 1.2.1 above, there are several reviews on the properties of RuO as an oxidant in organic chemistry, both as a stoicheiometric but also as a catalytic reagent [12, 34-36, 39, 60, 64, 201-203]. It is one of the most important and versatile of Ru oxidants. In the first few years after its properties in the field were realised it was often used for oxidation of alcohol groups in carbohydrates, but its versatility as an oxidant quickly became apparent and its use was extended to a variety of other reactions, notably to alkene cleavage and, more recently, to the c/x-dihydroxylation and ketohydroxylation of alkenes. 

Included in this section are oxidations of benzene and phenyl rings, and in general the oxidation of aromatic and polycyclic aromatic compounds. The main catalyst for this type of reaction is RuO. The earliest example was the use of stoich. RuOy CCI4 for phenanthrene oxidation [239], while the first catalytic reagent was RuO / aq. Na(I04)/acetone for oxidation of pyrene [240]. Another early example was the conversion of diketo compounds to the nor-diketo acids, with concomitant destruction of the two phenyl rings by RuO /aq. NallO l/acetone (Fig. 3.18, 3.2.2.1) [206]. 

The most common gaseous pollutants released by construction materials, are NOx, SO2, H2S, O3, HCOOH, CH3COOH and HCHO, which potentially interact with metal alloys, either directly or as catalytic reagents [266]. The presence of... 

Alkaline hydrolysis, as compared to other methods of lignin degradation, has certain advantages. The catalytic reagents are inexpensive and available commercially, and require no elaborate method of preparation. 

The principal difference between these catalyst level reaction rates and the turnover frequency is that the latter does not depend on the surface arrangement of the catalyst, or in more practical terms, does not depend on the specific physicochemical characteristics of the catalyst as a composite of the active catalytic reagent plus the support. 

ORGANOBORANE. A compound composed of an unsaturated organic group and a borane obtained by the hydroboration reaction. Such compounds are useful catalytic reagents in organic syntheses of some complexity, e,g, cis- or (/awf-olefins, optically pure alcohols, alkanes, and ketones. Prostaglandins and insect pheromones have been synthesized by tlus means. A particularly versatile example is triphenylboron B(CgHsty. See also Borane Carborane and Hydroboration. 

An interesting competition experiment was conducted on the steroid trienone (25), where the possibility for conjugate addition existed in three separate sites in the same molecule, C-l, C-5, and C-7 (equation 29). The catalytic reagent, MeMgl/Cul, gave only addition at C-l.76... 

Decarbonylation of aldehydes and acid halides is an important synthetic reaction (i, 2) and using various transition-metal complexes as stoichiometric or catalytic reagents for this process has... 

Smith AB, Jurica JA et al (2008) Total synthesis of (+)-psymberin (irciniastatin A) catalytic reagent control as the strategic cornerstone. Org Lett 10 5625-5628... 

Alkyl and aryl sulfides RSH react with equimolecular amounts of p-toluenesulfonyl-acetylene, HC C-SC Tol, in CH3CN at 0 °C or room temperature in the absence of any catalytic reagent to give Z-adducts RS-CH=CH-S02Tol with total diastereo-selectivity. On the other hand, in the presence of 1.1 equiv. of NaH in THF, the same reaction affords the corresponding li-diastereoisomers also with total diastereoselec-tivity.211... 

All of the previously mentioned reagents, despite their effectiveness, have an important drawback. They are used in stoichiometric amounts and, accordingly, are often costly. Their use involves separation and purification steps that can be troublesome. Very often, efficient recycling of the ligand cannot be achieved. Both researchers and industrial chemists have designed catalytic reagents to overcome this limitation. 

EC process — Figure. Influence of the concentration of the catalytic reagent Z to the current components of the cyclic voltammograms by an EC reaction... 

New, preferentially stereoselective, catalytic reagents will produce enantio-merically pure products, the specific chemical activity of which reduces adverse effects when applied in agriculture or medicine. Biocatalysis will continue to play an important role here. 

D - Degradable chemical products U - Use safe synthetic methods C - Catalytic reagents T - Temperature, pressure ambient... 

These hydroxy-1,1 -binaphthyl functionalised NHC ligands can be used in asynunetric catalysis. Catalytic reagents performed with transition metal catalysts carrying these ligands include olefin metathesis [19,80,86], allylic alkylation [17,18,88] and hydrosilylation of ketones [85]. 

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