C mechanistic aspects

Dworzanski, J. R Berwald, L. McClennen, W. H. Meuzelaar, H. L. C. Mechanistic aspects of the pyrolytic methylation and transesterification of bacterial cell wall lipids. /. Anal. Appl. Pyrolysis 1991,21,221-232. 

Chan, A. S. C., Chen, C. C., Yang, T. K., Huang, J. H., Lin, Y. C. Mechanistic aspects of Ru(BINAP)-catalyzed asymmetric hydrogenation of vinyl carboxylic acid derivatives. Inorg. Chim. Acta 1995, 234, 95-100. 

Binotti, B. Carfagna, C. Gatti, G Martini, D. Mosca, L. Pettinari, C. Mechanistic aspects of isotactic CO/styrene copolymerization catalyzed by oxazoline palladium(II) complexes. Organometallics 2003, 22, 1115-1123. 

Darensbouig, D.J. Banch, C.G. Ovalles, C. Mechanistic Aspects of Catalytic Carbon Dioxide Methanation. Rev. Inorg. Chem. 1985,7, 315-339. 

Darensbourg, D. J. Yarbrough, J. C. Mechanistic Aspects of the Copolymerization Reaction of Carbon Dioxide and Epoxides, Using a Chiral Salen Chromium Chloride Catalyst. J. Am. Chem. Soc. 2002,124, 6335-6342. 

Mechanistic aspects of the photosubstitution and photoisomerisation reactions of d6-metal complexes. P. C. Ford, D. Wink and J. Dibenedetto, Prog. Inorg. Chem., 1983.30, 213-271 (182). 

Luche and coworkers [34] investigated the mechanistic aspects of Diels-Alder reactions of anthracene with either 1,4-benzoquinone or maleic anhydride. The cycloaddition of anthracene with maleic anhydride in DCM is slow under US irradiation in the presence or absence of 5% tris (p-bromophenyl) aminium hexachloroantimonate (the classical Bauld monoelectronic oxidant, TBPA), whereas the Diels Alder reaction of 1,4-benzoquinone with anthracene in DCM under US irradiation at 80 °C is slow in the absence of 5 % TBPA but proceeds very quickly and with high yield at 25 °C in the presence of TBPA. This last cycloaddition is also strongly accelerated when carried out under stirring solely at 0°C with 1% FeCh. The US-promoted Diels Alder reaction in the presence of TBPA has been justified by hypothesizing a mechanism via radical-cation of diene, which is operative if the electronic affinity of dienophile is not too weak. 

Dias L. C. Chiral Lewis Acid Catalysts in Diels-Alder Cycloadditions Mechanistic Aspects and Synthetic Applications of Recent Systems J. Braz. Chem. Soc. 1997 8 289-332... 

The biologically uncommon Ni center associated with FeS clusters is a powerful and unique catalytic unity. In this chapter we have reviewed the structural and mechanistic aspects of three NiFeS centers the active site of hydrogenase and Clusters A and C of CODH/ACS. In the former, the association of a Ni center with the most unusual FeCOCN2 unit is a fascinating one. Model chemists, spectroscopists, and crystallographers have joined efforts to try and elucidate the reaction mechanism. Although a consensus is being slowly reached, the exact roles of the different active site components have not yet been fully established. Ni appears to be the catalytic center proper, whereas the unusual Fe center may be specially suited to bind a by-... 

Ford, P.C. and Lorkovic, I.M. (2002) Mechanistic aspects of the reactions of nitric oxide with transition-metal complexes, Chem. Rev., 102, 993, and references therein. 

Meunier, F.C., Breen, J.P., Zuzaniuk, V. et al. (1999) Mechanistic aspects of the selective reduction of NO by propene over alumina and silver-alumina catalysts, J. Catal., 187, 493. 

D Ham, C. Romieu, A. Jaquinod, M. Gasparutto, D. Cadet, J. Excision of 5,6-dihydroxy-5,6-dihydrothymine, 5,6-dihydrothymine, and 5- hydroxycytosine from defined sequence oligonucleotides by Escherichia coli endonuclease III and Fpg proteins Kinetic and mechanistic aspects. Biochemistry 1999, 38, 3335-3344. 

S) Juday, R. E. Symposium on the Synthetic and Mechanistic Aspects of Organic Electrochemistry, U.S. Army Research Office, Durham, N.C., USA, October 14—16, 1968,p.211. 

While a number of studies have reported on stereochemical and mechanistic aspects of the carbene addition to unsaturated bonds,1 C-H insertion reactions... 

Fig. 1. Amperometric monitoring of the autoxidation of epigallocatechin gallete in the presence of (A) 0, (B) 2.0, (C) 5.0, (D) 10, (E) 20, and (F) 50 pm CuCl2. The measurements were performed in 0.1 M Tris buffer (pH 9.0) with a Clark type oxygen electrode at 28 °C. The epigallocatechin gallate concentration was fixed at 50 pm. The catechin stock solution was injected into the test solution at t = 0. The inset shows the (initial) steady-state autoxidation rate as a function of Cu2+ concentration. Reprinted from Biochimica et Biophysica Acta, vol. 1569, Mochizuki, M. Yamazaki, S. Kano, K. Ikeda,T., Kinetic analysis and mechanistic aspects of autoxidation of catechins, p. 35, Copyright (2002), with permission from Elsevier Science.

Complexes and Their Reactions Floriani, Carlo, see Piarulli, Umberto Ford, Peter C., Wink, David, and DiBenedetto, John, Mechanistic Aspects of the 17 1... 

Hill, C.A.S., Jones, D., Strickland, G. and etin, N.S. (1998). Kinetic and mechanistic aspects of the acetylation of wood with acetic anhydride. Holzforschung, 52(6), 623-629. 

C=X bonds The stereochemistry of the reduction of carbonyl compounds has been intensely studied with regard to synthetic and mechanistic aspects. The reduction of 1,2-diphenyl-l-propanone at a Hg cathode in aqueous EtOH and pH 8 affords the erythro alcohol as the major diastereomer (erythro threo = 5 to 1.4 1) [332]. This selectivity is in accord with a protonation of the intermediate anion, formed in an ECE sequence, from the least hindered side (Fig. 61). 

B37. W. L. Reynolds and R. W. Lumry, Mechanisms of Electron Transfer, Ronald Press, NY, 1966. B38. D. B. Rorabacher and J. F. Endicott (eds.) Mechanistic Aspects of Inorganic Reactions, ACS Symposium Series, 198, American Chemical Society, Washington, D.C. 1982. 

The carbon of complexed CO, i. e., M-CO, can appear at either a lower or higher frequency than CO itself depending on the metal. A useful list of CO chemical shifts can be found in a study describing mechanistic aspects of the Rh- and Ir-cat-alyzed carbonylation of methanol [59]. Additional C NMR data on Rh-acyl intermediates, derived from the Rh-catalyzed carbonylation of ethene, e. g., 60, have been reported [60]. 

Matyjaszewski, K. and C. Pugh, Introduction, Chap. 1 and Mechanistic Aspects of Cationic Polymerization of Alkene, Chap. 3 in Cationic Polymerizations Mechanisms, Synthesis, and Applications, K. Matyjaszewski, ed., Marcel Dekker, New York, 1996. 

For a monograph, see Cerfontain Mechanistic Aspects in Aromatic Sulfonation and Desulfonation Wiley New York. 1968. For reviews, see Cerfontain Reel. Trav. Chim. Pays-Bas 1985, 104, 153-165 Cerfontain Korl Int. J. Sulfur Chem. C 1971, 6, 123-136 Taylor, in Bamford Tipper, Ref. I, pp. 56-77. 

A systematic study to identify solid oxide catalysts for the oxidation of methane to methanol resulted in the development of a Ga203—M0O3 mixed metal oxide catalyst showing an increased methanol yield compared with the homogeneous gas-phase reaction.1080,1081 Fe-ZSM-5 after proper activation (pretreatment under vacuum at 800-900°C and activation with N20 at 250°C) shows high activity in the formation of methanol at 20°C.1082 Density functional theory studies were conducted for the reaction pathway of the methane to methanol conversion by first-row transition-metal monoxide cations (MO+).1083 These are key to the mechanistic aspects in methane hydroxylation, and CuO+ was found to be a likely excellent mediator for the reaction. A mixture of vanadate ions and pyrazine-2-carboxylic acid efficiently catalyzes the oxidation of methane with 02 and H202 to give methyl hydroperoxide and, as consecutive products, methanol and formaldehyde.1084 1085... 

Griffiths. J. and C. Hawkins Mechanistic Aspects of the Photochemistry of Dyes and Their Immediates, f. Soc. Dyers Colorists, 89. 173 (1973). 

Mechanistic investigations by Chapman and co-workers (99) indicated that these reactions occurred via a nonfluorescent singlet exciplex intermediate. While the rate constant for quenching of - -t5 by 2,3-dimethy 1-2-butene is slower than the rate of diffusion (Table 8), the limiting quantum yield for cycloaddition is 1.0. Thus, highly efficient exciplex cycloaddition may account for the absence of exciplex fluorescence, as in the case of t-1 photodimerization. Photochemical [2+2] cycloaddition reactions have also been observed to occur upon irradiation of the cyclic c-1 analogues diphenylcyclobutane (7) and diphenyl-vinylene carbonate (10) with 2,3-dimethyl-2-butene (96) however, the mechanistic aspects of these reactions have not been investigated. 

Examples of C02 insertion into M-H and M-C bonds are numerous. Less common are instances of carbon dioxide insertion into M-O and M-N bonds. There are excellent reviews which encompass these areas by Eisenberg and Hendriksen (4), Volpin and Kolomnikov (24), Kolomnikov and Grigoryan (25), and Sneeden (26). Hence we will emphasize developments since the time of these reviews (i.e., from 1979 to present) with our perspective being primarily that of understanding mechanistic aspects of these insertion processes. Some overlap with these earlier reviews will necessarily occur during such efforts. 

---