Substituted aromatic compounds

This chapter deals with anodic oxidation of saturated hydrocarbons, olefins, and aromatic compounds. Substituted hydrocarbons are included, when the substituents strongly influence the reactivity. Anodic functional group interconversions (FGI) of the substituents are covered in Chapters 6, 8-10 and 15. 

Aromatic compounds, substituted in 1,4-position with methoxy or hydroxy groups, undergo 1,4-addition with loss of the aromaticity (Eq. 21) (Table 15, numbers 1,2). 

Dorn, E. and Knackmuss, H.J., Chemical structure and biodegradability of haloge-nated aromatic compounds substituted effects on 1,2-dioxygenation of catechol, Biochem.., 174, 85, 1978. 

The correlation was developed with a correlation coefficient of 0.903. The correlation was able to accurately predict the first-order degradation rate constants as a function of Brown s constant, the octanol/water partition coefficient, and molar refractivity. This correlation held for a broader class of aromatic compounds substituted at the meta and para positions, as compared to a simple substitution at one position on the aromatic ring. Table 9.6 lists the experimental and predicted values for the first-order degradation rate constants of substituted anisoles. 

Aromatic compounds substituted by a heteroatom can be oxidized to corresponding quinone derivatives using hypervalent iodine reagents. Phenols can be oxidized either in the ortho [84] or in the para position [85] by using iodine(III) reagents. By this route, benzothiazoles of type 36, Scheme 17, are accessible and they have been tested as antitumor compounds [86,87]. 

A second limitation is that aromatic compounds substituted with moderately or strongly deactivating groups cannot be alkylated. The deactivated ring is just too poor a nucleophile to react with the unstable carbocation electrophile before other reactions occur that destroy it. 

Regioselective chlorination. This N-chloroammonium salt (1) as well as N-chlo-ropiperidine, chlorinates aromatic compounds substituted with an electron-donating group with high para-selectivity. Benzene and toluene are attacked only slowly. 

The Heck reaction was discovered independently in the end of 1960s by T. Mizoroki and R. F. Heck . But Heck developed it into a synthetically useful reaction. Since then it has become one of the most important reactions for the synthesis ° of aromatic compounds substituted with alkenes. 

Aromatic compounds substituted by electron-donating groups such as aniline, A-methylani-line, A/,A-dimethylaniline, phenol, anisole, and indole undergo nucleophilic addition across the N(3)-C(4) bond of quinazoline in 1 M sulfuric acid to give the corresponding 4-aryl-3,4-dihy-droquinazolines 20. ... 

Aromatic compounds substituted with amino groups, e.g., heterocyclic aromatic amines present in protein food products, are usually activated by cytochrome P450 to hydroxylamines. This type of metabolism is observed in the case of 3-amino-1-methyl-5//-pyrido[4,3-/ ]indolc (Trp-P-2). 

The U.V., i.r., and H n.m.r. absorptions of 1000 simple aromatic compounds substituted by hydroxy-, methoxy-, and methylenedioxy-groups have been collected as a possible aid to identification of alkaloid degradation products. Homobenzylic and homoallylic spin-spin coupling interactions in some octahydro- and hexahydro-phenanthridines have been discussed. 

Easic Principles Practical Photochemistry General Considerations Carbonyl Compounds a-Cleavage Carbonyl Compounds Hydrogren Abstraction Steroids Carbonyl Compounds Cycloaddition Enone and Dienone Rearrangements Alkenes Isomerisation and Rearrangement Alkenes Cycloaddition Alkenes Photo-Cxidation Terpenoids Aromatic Compounds Isomerisation and Cycloaddition Practical Photochemistry Scale-up Aromatic Compounds Substitution and Cydisation Alkaloids Photoinitiated Free-radical Chain Reactions. 

Results found in the literature are compiled in Table 1. Investigations on secondary kinetic isotope efifects in electrophilic substitutions are included, but not measurements on acid-base equilibria and rates of side-chain groups of aromatic compounds substituted by deuterium or tritium in the aromatic nucleus. 

Aromatic compounds, substitution products and condensed systems, such as diphenyl, terphenyl, pyrene, anthracene and chrysene... 

The apparent ease with which the quinoline derivatives comply with these correlations is surprising. However, it should be remembered that, as in the case of the aromatic compounds, substitution by strongly polar groupinp will materially alter these CH frequencies. 

Perhaps the most important preparative use of aryl free radicals is in the synthesis of biaryls. If an aryl free radical is generated in the presence of a second aromatic compound, substitution leading to the biaryl is observed. Yields in this... 

Aryl chlorides do not form Grignard reagents when ether is the solvent. As a result, an aromatic compound substituted with both bromine and chlorine can be selectively converted into a Grignard reagent at the site of the bromine atom. 

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