Carbonyl compounds nitriles

It has been reported that an allylic C-Si bond can be cleaved by tetrabutylammonium fluoride to give an anionic allylic species, which chemoselectively adds to carbonyl compounds (nitriles, esters, and epoxides failed) to form homoallylsilyloxy compounds13. 

Since hydrocarbon subunits (methyl, methylene and methine groups) are not polarized to a great extent, their nature can be defined by a polar substituent. The high acidity of the a-hydrogen atoms of carbonyl compounds, nitriles, sulfones, and nitroalkanes follows from polarity alternation, the carbon atoms being a donor next to the acceptor substituent. 

Many other uses of a-sulfinyl carbanions are found in the literature, and in the recent past the trend has been to take advantage of the chirality of the sulfoxide group in asymmetric synthesis. Various ways of preparation of enantiopure sulfoxides have been devised (see Section 2.6.2) the carbanions derived from these compounds were added to carbonyl compounds, nitriles, imines or Michael acceptors to yield, ultimately, with high e.e. values, optically active alcohols, amines, ethers, epoxides, lactones, after elimination at an appropriate stage of the sulfoxide group. Such an elimination could be achieved by pyrolysis, Raney nickel or nickel boride desulfurization, reduction, or displacement of the C-S bond, as in the lactone synthesis reported by Casey [388]. 

The amide ions are powerful bases and may be used (i) to dehydrohalogenate halo-compounds to alkenes and alkynes, and (ii) to generate reactive anions from terminal acetylenes, and compounds having reactive a-hydrogens (e.g. carbonyl compounds, nitriles, 2-alkylpyridines, etc.) these anions may then be used in a variety of synthetic procedures, e.g. alkylations, reactions with carbonyl components, etc. A further use of the metal amides in liquid ammonia is the formation of other important bases such as sodium triphenylmethide (from sodamide and triphenylmethane). 

The double bonds of electron-deficient olefins (carbonyl compounds, nitriles, sulfones, sulfoxides, nitro derivatives, etc.) have a low-lying LUMO that can allow the attack of various nucleophiles. The nucleophiles can be neutral or negatively charged heteroatomic species, or they can be carbon species such as organometal-lic reagents or enolates. In the case of heteroatomic nucleophiles, asymmetric additions can be performed in the presence of chiral catalysts, with chiral reagents, or with substrates bearing chiral residues. 

Activated hollow spheres have been found to be advantageous for the hydrogenation of carbonyl compounds, nitriles, aromatics, and unsaturated C-C bounds. In the case of carbonyl conqrounds, promoters (e.g.. Mo and Cr) that exist as surface cations were found to be the most effective. In the case of nitriles, the use of promoters to stabilize the residual A1 content of the catalyst so that it can be used with base modifiers was found to be the most useful combination. An example of this was the improved performance of the LiOH treated Cr / Ni promoted Co hollow spheres for the hydrogenation of adiponitrile to hexamethylenediamine. Some reactions were found to be more sensitive to the type of promoter they require. In the case of l,4-dihydroxy-2-butyne, it was found that Mo worked satisfactory as a promoter while the Cr / Fe combination led to worse results. Nonetheless, for all of the reactions studied here it was found that the activate hollow spheres were more active than the activated tablets on both a volume and weight basis, thereby allowing increased flexibility in the use of promoters and other selectivity enhancing additives. 

In the presence of alkaline catalysts alcohols can undergo nucleophilic addition to the C=C double bond of, / -unsaturated carbonyl compounds, nitriles, sulfones, or sulfoxides. Similarly the doubly bonded carbon atoms in polyfluoroethylenes are susceptible to nucleophilic attack by alcohols in the... 

Since the S-H bond is only slightly polarized and heterolysis to a proton and a mercaptide ion is thus difficult,19 the addition to olefins is preferably carried out by a radical route induced by benzoyl peroxide12 by irradiation with UV light.13 Alkanethiols and thiophenols can be added under the influence of basic catalysts to strongly polar double bonds such as those in unsaturated carbonyl compounds, nitriles, and carboxylic acids, the C-S bond then being formed to the cationic / -carbon atom ... 

In the present review the role of supported metal ion - metal nanocluster ensemble sites in activity and selectivity control of different catalytic reactions will be discussed. Evaluation of literature data and interpretation of author s recent results obtained in the activation of different organic carbonyl compounds, nitriles, and the CO molecule will be given. The catalytic performance of metallic nanoclusters promoted by metal ions or reducible metal oxides will be discussed in separate chapters according to the type of metal forming the nanocluster. 

The methods for generating acyl ketenes (Scheme 7-V) and their subsequent in situ participation in [4 + 2] cycloadditions with a wide range of hetero- or olehnic and acetylenic dienophiles (Scheme 7-VI), including acyl ketenes, carbonyl compounds,nitriles,isocyanates and isothiocyanates,ketenes,(mines,carbo-diimides, ynamines, ketene acetals, enol ethers,and V-sulfinylamines have been extensively reviewed.Two reports have detailed the 4tt participation of allenic ketones in [4 + 2] cycloaddition reactions [Eq. (51)]. ... 

In organic chemistry, oxidation and reduction processes are different from ordinary redox reactions because in many cases they do not involve direct electron transfer but may involve a decrease in electron density around a molecule or loss/gain of hydrogen. Oxidation reactions are useful to convert alcohols into carbonyl compounds, nitriles into acids, and amines into imines. SSA along with a suitable reagent such as oxone or sodium nitrite serves as a powerful oxidant. This part of the chapter encompasses the oxidation reactions catalyzed by SSA. 

Between 1961 and 1967 the electrochemical generation method has been used to obtain, identify, and investigate free radicals derived from about 400 different organic compounds, such as unsaturated acyclic and alicyclic hydrocarbons, condensed and noncondensed polynuclear aromatic hydrocarbons, heterocyclic compounds, quinones, carbonyl compounds, nitriles, nitroso and nitro derivatives, and carboxylic esters. 

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