Manifold reaction

Like those of all the simple aliphatic diazo-compounds the manifold reactions of ethyl diazoacetate are determined by the lability of the nitrogen. The elimination of the latter is catalytically accelerated by aqueous acids, and, indeed, the velocity of decomposition is directly proportional to the hydrogen ion concentration, so that a means is provided by which this concentration can be measured for acids of... 

Mechanisms of the manifold reactions of a-dialkylamino alkyllithium intermediates R(Me2N)CLiNu, formed when tertiary amides (RCONMc2) react with PhMc2SiLi followed by a second lithium reagent NuLi, have been discussed. The formation of diverse products following 1 1 insertion of an isonitrile RNC into the Li-C bond of LiCH(SiMc3)2 has been discussed. ... 

On the background of the impressive studies summarized herein, it can be expected that even more manifold reactions exploiting the carbene-catalyzed um-polung of aldehydes will be discovered in the future [69]. 

Since the manifold reactions of the glycals are rather confusing, a review of the most important results in this field is given in the following paragraphs. In this summary the substitution at the hydroxyls and the configuration of the individual carbon atoms will be considered only in so far as these are of importance to the reactions themselves.61... 

The electrolysis of aromatic acids by no means offers results which are comparable to those obtained by the electrolysis of aliphatic acids. In so far as the aromatic acids, or their salts, act as electrolytes, a regeneration of the acid from the anion RCOO and water, with evolution of oxygen, occurs almost exclusively. A splitting off of carbonic acid, which makes possible the manifold reactions of aliphatic acids, almost never occurs here. The results obtained with aromatic acids are, therefore, only of a more general interest so far as the acids, by substitutions in the benzene nucleus, can act as cathodic or anodic depolarizers, and can in this way exert reduction and oxidation effects. 

Considering the manifold reaction pathways available for caibocations it is not suiprising that unexpected products have been isolated. Capture of the intermediate cyclopentenyl cation by nucleophiles was fust shown by Shoppee (Scheme 6). This pathway can become dominant, resulting in a transposition of the enone moiety by tautomerization and dehydration. 

Among the manifold reactions in snow the photolysis of nitrate (NO3 ) is now the best characterized reaction due to a range of laboratory experiments. These studies have been used to extract information about the absorption coefficients and quantum yields of NO3 in ice as a function of wavelength, the formation of products like the hydroxyl radical (OH) and nitrite (N02), and the release of NOx to the gas phase. Limited information regarding the absorption coefficients and the formation of OH radicals can also be found for the photolysis of H202. " Investigations regarding the photolytic decomposition of further compounds with a potential relevance for photochemical processes in surface snow are limited to studies, in which reactions of HCHO and NO2 have been examined. 

Alkaloids occupy an important position in commerce and forensic chemistry, and in medicine they play a role that, in many instances, may be classed as indispensable. Because of their multiplicity of type and their unique and manifold reactions, alkaloids offer to the chemist a challenge shared by no other single class of organic compounds. There are few organic reactions that have not proved useful in the field of alkaloid chemistry, while in turn many of the reactions developed in this field of natural products have found extensive application in other branches of organic chemistry. 

XXVIIa XXYII6). Thus a hydrogen atom a to such a group rill be relatively easily removed by basic reagents, and the resulting anion may undergo the manifold reactions characteristic of such centers. These... 

Following and determining the rates of the manifold reactions that occur in the formation of even a single adduct are difficult tasks. Using [ H, N] 1D/2D HSQC to monitor the reaction between N-labeled platinum complexes and nucleobases or DNA is particularly attractive because species can be acquired quickly (in as little as 3-4 min) and all platinated species are observed at micromolar concentrations. The interaction between N-dsplatin... 

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