Russell reaction

Another example of sonochemical switching is found in the Kornblum-Russell reaction (Scheme 3.9). 4-Nitrobenzyl bromide reacts with 2-lithio-2-nitro-propane via a predominantly polar mechanism to give, as a final product, 4-nitrobenzaldehyde [57]. An alternative SET pathway exists in this reaction leading to the formation of a dinitro compound. Sonication changes the normal course of the reaction and gives... 

Fig. 6.18 Modes of decomposition of intermediary aliphatic tetroxides (Russell reactions) via electrocyclic rearrangements, with or without water taking part (von Sonntag and Schuchmann, 1991), or via one-electron shifts.

Sonochemical switching was observed in the Komblum-Russell reaction (Fig. 33). 2-Lithio-2-nitropropane is an ambident anion which reacts under stirring with 4-nitrobenzyl bromide at the oxygen atom via a predominant polar mechanism giving 4-nitrobenzaldehyde as the final product. In contrast, alkylation at the carbon atom occurs via a less favored SET pathway and provides a dinitro compound. 

In the case of PP, where the terminating radicals are both expected to be tertiary, the Russell reaction is not possible and bimolecular interaction of radicals is believed to follow the path... 

In the post-irradiation oxidation process, the rate of oxidation decreases by more than one order of magnitude in the first 100 hours, although alkyl macroradicals are continuously formed along with the formation of hydroperoxides (Scheme 9, Reaction 23). The termination reaction of thermo-oxidative processes is generally described as a Russell reaction between two peroxy species. The relative inunobility and the stability of the peroxy radical makes the Russell bimolecular termination strongly disfavored in the solid state at room temperature [22, 23]. More likely. 

Methyl ethyl ketone, a significant coproduct, seems likely to arise in large part from the termination reactions of j -butylperoxy radicals by the Russell mechanism (eq. 15, where R = CH and R = CH2CH2). Since alcohols oxidize rapidly vs paraffins, the j -butyl alcohol produced (eq. 15) is rapidly oxidized to methyl ethyl ketone. Some of the j -butyl alcohol probably arises from hydrogen abstraction by j -butoxy radicals, but the high efficiency to ethanol indicates this is a minor source. 

E. S. Huyser, Free Radical Chain Reactions, Wiley-Interscience, New York, 1970, Chapter 4 G. A. Russell, in Free Radicals, Vol. 1, J. Kochi, ed., John Wiley Sons, New York, 1973, Chapter 7. 

Hydrotreating Technology for Pollution Control Catalysts, Catalysis, and Processes, edited by Mario L. Occelli and Russell Chianelli Catalysis of Organic Reactions, edited by Russell E. Malz, Jr. 

The ability of a nltro group in the substrate to bring about electron-transfer free radical chain nucleophilic subsdnidon fSpj li at a saniratedcarbon atom is well documented. Such electron transfer reacdons are one of the characterisdc feanires of nltro compounds. Komblum and Russell have established ihe Spj l reaction independently the details of the early history have been well reviewed by them. The reacdon of -nitrobenzyl chloride v/ith a salt of nitro ilkane is in sharp contrast to the general behavior of the ilkyladon of the carbanions derived from nitro ilkanes here, carbon ilkyladon is predominant. The carbon ilkyladon process proceeds via a chain reacdon involving anion radicals and free radicals, as shovmin Eq. 5.24 and Scheme 5.4 fSpj l reacdoni. 

From the foregoing it can be seen that the nitro group can be activated for C-C bond formation in various ways. Classically the nitro group facilitates the Henry reaction, Michael addition, and Diels-Alder reaction. Komblum and Russell have introduced a new substitution reaction, which proceeds via a one electron-transfer process The Spj l reactions have... 

A radical polymerization involves free radical ends which of course do not associate and which interact only weakly with solvents. Consequently, the early investigators assumed that the course of propagation of radical polymerization is independent of the environment (see, for example, the recent monograph by Walling60). Actually, more recent studies, notably by Russell,36 showed that the nature of the solvent sometimes might considerably affect even the course of radical reactions. Therefore, unusual behavior of the propagation step might be expected in certain solvents. 

The first reports on this reaction were published almost simultaneously by Russell and coworkers533 and Corey and Chaykovsky534, who reacted dimsyl anion with a variety of carboxylic esters and obtained the corresponding a-ketosulphoxides 464 in high yields (equation 277 Table 25). 

Flamers R. J., Coulter S. K., Ellison M. D., Flovis J. S., Padowitz D. F., Schwartz M. P., Greenlief C. M., Russell J. N. Jr Cycloaddition Chemistry of Organic Molecules With Semiconductor Surfaces Acc. Chem. Res. 2000 33 617 624 Keywords carbonyi group, semiconductor materiais, surface reaction, aikenes, aromatic compounds, azo compounds, cycioaikadienes, isothiocyanates, unsaturated compounds... 

To be able to explain chemical reactions, students will have to develop mental models of the submicroscopic particles of the substances that undergo rearrangement to produce the observed changes. However, students have difficulty in understanding submicroscopic and symbolic representations as these representations are abstract and carmot be directly experienced (Ben-Zvi, Eylon, Silber-stein, 1986, 1988 Griffiths Preston, 1992). As a result, how well students understand chemistry depends on how proficient they are in making sense of the invisible and the untouchable (Kozma Russell, 1997 p. 949). 

The sub-micro level is real, but is not visible and so it can be difficult to comprehend. As Kozma and Russell (1997) point out, understanding chemistry relies on making sense of the invisible and the untouchable (p. 949). Explaining chemical reactions demands that a mental picture is developed to represent the sub-micro particles in the substances being observed. Chemical diagrams are one form of representation that contributes to a mental model. It is not yet possible to see how the atoms interact, thus the chemist relies on the atomic theory of matter on which the sub-micro level is based. This is presented diagrammatically in Fig. 8.2. The links from the sub-micro level to the theory and representational level is shown with the dotted line. 

This diagram may appear trivial to the expert chemist but for a novice it contains much information about the chemical reaction at both the sub-micro and symbolic levels presented in multiple representational formats. Unless teachers are explicit in their use of these representations it is umealistic to assume that students would develop the same ability to choose an appropriate representation for a given process. It is possible that students can use and understand the representations without being able to see how they are related. Several authors (Hinton and Nakhleh, 1999 Kozma and Russell, 1997 Nurrenbem and Pickering, 1987) suggest that students are made aware of all three levels of representations and given opportunities to use them in solving problems. 

In summary, according to the recommendations of researchers (Hinton Nakhleh, 1999 Russell et al., 1997 Tasker, Chia, Bucat, Sleet, 1996), it is cmcial to teach about chemical reactions by helping students to draw links between the... 

The first example of a tetrakisimido analogue of the orthophosphate ion, PO, the solvent-separated ion pair [(THF)4Li][(THF)4Li2P(Nnaph)4] (16), was reported by Russell et al. [21]. This complex was isolated in low yield from the reaction of P2I4 with a-naphthylamine in THF/NEt3, followed by the addition of "BuLi. The mechanism of this remarkable redox process is not understood. 

Russell, C. D. Cotlove, E. Serum glutamic-oxaloacetic transaminase Evaluation of a coupled-reaction enzyme assay by means of kinetic theory. Clin. Chem. (1971), 17, 1114-1122. 

Lipase-catalyzed reaction is useful for polyester synthesis and IE was employed successfully as solvent. Uyama and Kobayashi demonstrated an efficient polyester synthesis lipase-catalyzed esterification of agipic acid with butan-1,4-diol proceeded smoothly in [bmim][BF4] solvent, particularly under reduced pressure conditions (Fig. 8). Further Russel " and Nara independently reported efficient examples of the lipase-catalyzed polyester synthesis in an IE solvent system. 

Complex reactions can be conveniently investigated by simulation techniques. In this example from Russell and Denn (1972), the characteristics of the following complex reaction can be investigated. 

Catalysis of Organic Reactions, edited by Russell E. Malz, Jr. 

Ito et a/.18 supported the above reaction pathways for various cathode materials, such as In, Sn, Cd, and Pb, from the similarity in Tafel slopes. Hori and Suzuki46 verified the above mechanism in various aqueous solutions on Hg. Russell et al.19 also agreed with the above mechanism. Adsorbed CO J anion radical was found as an intermediate at a Pb electrode using modulated specular reflectance spectroscopy.47 This intermediate underwent rapid chemical reaction in an aqueous solution the rate constant for protonation was found to be 5.5 M-1 s-1, and the coverage of the intermediate was estimated to be very low (0.02). 

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