Arene oxides with amines

In general, nucleophilic addition reactions of arene oxides with nonpolarizable oxygen and nitrogen nucleophiles are very slow. Thus both NH3 and NHj nucleophiles failed to add to benzene oxides under a range of conditions. Amine nucleophiles have, however, been found to react very slowly with benzene oxide. 

The first chapter concerns the chemistry of the oxidation catalysts, some 250 of these, arranged in decreasing order of the metal oxidation state (VIII) to (0). Preparations, structural and spectroscopic characteristics are briefly described, followed by a summary of their catalytic oxidation properties for organic substrates, with a brief appendix on practical matters with four important oxidants. The subsequent four chapters concentrate on oxidations of specific organic groups, first for alcohols, then alkenes, arenes, alkynes, alkanes, amines and other substrates with hetero atoms. Frequent cross-references between the five chapters are provided. 

As with arene-amine radical ion pairs, the ion pairs formed between ketones and amines can also suffer a-deprotona-tion. When triplet benzophenone is intercepted by amino acids, the aminium cation radical can be detected at acidic pH, but only the radical formed by aminium deprotonation is detectable in base (178). In the interaction of thioxanthone with trialky lamines, the triplet quenching rate constant correlates with amine oxidation potential, implicating rate determining radical ion pair formation which can also be observed spectroscopically. That the efficiency of electron exchange controls the overall reaction efficiency is consistent with the absence of an appreciable isotope effect when t-butylamine is used as an electron donor (179). 

The K-region oxides undergo nucleophilic addition with OH", C032", water, amines, and mercaptides.88,140 The second-order rate constants for the reactions of OH", water, and primary and secondary amines with 1 at 30°C and with ethylene oxide at 25°C141 can be simply related by Eq. (6),2 which shows that the sensitivity of the two oxides to the nature of the nucleophile is similar and that the arene oxide is more reactive. 

A wide variety of hydrocarbons, including alkanes, alcohols, amines and arenes, could be oxidized with 02 in the presence of mixed-addenda POMs, [PV Mo12 nO40](3 + n) (6.2 and 6.3) [52-67] ... 

Diaryl tellurides undergo facile ligand-transfer oxidations with [bis(acyl-oxy)iodo]arenes in chloroform to give stable diaryltellurium dicarboxylates 12 (Scheme 7) [23]. Similar ligand-transfer oxidations of triarylbismuthanes and triarylstibanes with BAIB in dichloromethane leading to Bi(V) and Sb(V) diacetates 13 and 14 have also been reported [24,25]. The triarylbismuth diacetates were employed for high yield Cu(II)-catalyzed arylations of a series of aryl-amines [24]. 

Intramolecular nucleophilic attack of an amine group on an arene oxide has been proposed to account for the biosynthesis of a range of epipolythiopiperazine-diones (e.g., gliotoxin, bis-dithiobis-(methylthio)dehydrogliotoxin, spirodesmins, etc.)- With the amine-substituted arene oxides 50 and 55 (Figure 3), synthe-... 

General acid catalysis in the hydrolysis of 81 is quite facile. This reaction, as discussed in Section Benzylic epoxides and arene oxides and shown in Scheme 39, involves proton transfer to the epoxide oxygen concerted with epoxide C-O bond breaking to form a carbocation 83. For primary ammonium ions with pKa < 8, only the acid form of the amine is reactive, and carbocation formation is irreversible,... 

Compounds undergoing metabolic conjugation must possess within their structures a functional group appropriate for combination with the conjugating agent ( ). This Is generally Introduced by Phase I metabolism, and may either be chemically stable e.g. phenolic, alcoholic or carboxylic hydroxyl, amine, thiol or a cyclic heteroatom, or chemically reactive e.g. arene oxide, or carbonium Ion. 

Waldmann s safety-catch hydrazide linker is also part of the class of traceless linkers [55]. Starting from hydrazide resin 126, which is converted into an activated species by oxidation with Cu(OAc)2, the molecules are cleaved by the addition of nucleophiles like amines to give arenes 127 (Scheme 16.30). 

This reaction has also been applied to arene oxides. These oxides can be opened by alumina doped with alcohols and amines, but this reaction competes with 1,2-hydride shifts to give phenols. ... 

Arene imines. Blum et al have converted arene oxides into N-alkyi arene imines by reaction with an amine followed by cyclodehydration (method of Appel and Kleinstuck, 5, 727). The reaction is illustrated for preparation of phenan-threne-9,10-imines (equation I). For a different route to arene imines see 6, 541. 

---