Aromatic carbon-hydrogen bonds

Silylation of Aromatic Carbon-Hydrogen Bonds 359 SiPha... 

Aromatic carbon—hydrogen bonds, catalzyed borylation, 9, 172 Aromatic carbonyl compounds, in samarium pinacol couplings,... 

C. Giannotti, andM. L. H. Green, Photo-induced Insertion of Bis-7r-cyclopentadienyl-tungsten into Aromatic Carbon-Hydrogen Bonds, J. Chem. Soc., Chem. Comm. 1972, 1114-1115. 

Fuchita, Y, Hiraki, K., Kamogawa, Y. et al. (1989) Activation of aromatic carbon-hydrogen bonds by palladium(II) acetate-dialkyl sulfide systems. Formation and characterization of novel diphenyltripalladium(Il) complexes. Bull. Chem. Soc. Jpn., 62, 1081-5. 

For example (a) Weissman, H., Song, X. and Mdstein, D. (2001) Ru-catalyzed oxidative coupling of arenes with olefins using O2. /. Am. Chem. Soc., 123, 337-8 (b) Kakiuchi, R, Sato, T., Yamauchi, M. et al. (1999) Ruthenium-catalyzed coupling of aromatic carbon-hydrogen bonds in aromatic imidates with olefins. Chem. Lett., 28, 19-20. 

Full details (see Vol. 1, p. 185) of the Japanese work on the preparation of trifluoromethylarenes from trifluoroiodomethane and iodoarenes in the presence of copper powder and a dipolar aprotic solvent have become available, and it appears that the best solvent in some cases is pyridine. This method (but with DMF as solvent) has also been used to prepare the compounds PhR [R = Me03C (CF3)3, CF3 0 (CF2)2, or perfluoro-2-tetra-hydrofurfuryl] in good yields from iodobenzene and the corresponding polyfluoroiodo-compounds. Perfluoroalkyl-copper compounds are very probably involved in such reactions, and the reactions of preformed n-perfluoroheptylcopper in dimethyl sulphoxide with the aromatic carbon-hydrogen bonds of benzene, toluene, p-xylene, nitrobenzene, and chlorobenzene also lead to (perfluoroalkyl)arenes (some replacement of chlorine occurs in the case of chlorobenzene). Homolytic substitution by perfluoro-heptyl radicals, perhaps within the co-ordination sphere of the copper atom,... 

CARS microscopy derives its analytical capability from the Raman active modes of molecules [75]. There are two specific vibrational modes in the Raman spectra of acrylic based polymers that can give insights on the polymerization process and the structural integrity of microstructures fabricated via TPP. One is around 3000 cm and arises from the stretching of both aliphatic and aromatic carbon-hydrogen bonds. The other one is around 1640 cm and is due to the carbon-carbon double bond resonant vibration with the carbonyl group present in the acrylic units of the starting materials [73, 76]. 

Murai S, Kakiuchi F, Sekine S, et al. Efficient catalytic addition of aromatic carbon-hydrogen bonds to olefins. Nature. 1993 366 529-531. 

Aromatic carbon-hydrogen bond Phenols Synthesis of phenols Monooxygenase, dioxygenase, peroxidase... 

Systems usually fluonnated by electropositive fluorine reagents include acti-vated alkenes (enol ethers, enol acetates, silyl enol ethers, and enamines), activated aromatic systems, certain slightly activated carbon-hydrogen bonds, and selected organometallics. 

Because the cis-decalin molecule extends its two methine carbon-hydrogen bonds on the same side in contrast to frans-decalin, the carbon-hydrogen bond dissociation of adsorbed decalin would be advantageous to the cis-isomer on the catalyst surface (Figure 13.17). A possible reaction path by octalin to naphthalene in dehydrogeno-aromatization of decalin will be favored to the cis-isomer, since its alkyl intermediate provides the second hydrogen atom from the methine group to the surface active site easily. 

Oxidative attack on a carbon-hydrogen bond of an alkyl group a to a nitrogen atom is not restricted to saturated aliphatic amines. In fact X in an X-N-CH- structural subunit can be virtually any common atomic grouping that can be found in stable organic molecules. For example, w-carbon hydrogens of Aralkyl-substituted aromatic cyclic amines (119), aryl amines (120), amides (121), amidines (122), A-nitrosodialkylamines (123), etc. are all subject to oxidative attack, carbinolamine formation, and in most cases release of an aldehyde or ketone depending on the substitution pattern (1° or 2°)... 

To atomize the phenol molecule, we have to cleave six carbon-carbon bonds in the aromatic ring (Cb-Cb), five carbon-hydrogen bonds (Cb-H), one carbon-oxygen bond (Cb—O), and one oxygen-hydrogen bond (O-H). The symbol El has been adopted is this equation (instead of the more used symbol E) to avoid confusion with the quantities discussed in the previous section. 

A method has been described for he prediction of the pK s of carbon-hydrogen bonds in aromatic heterocycles including pteridines, in DMSO solution <2007T1568>. 

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