Arene oxides chemistry of

Bolt HM, Remmer H (1976) Implication of rifampicin-quinone in the irreversible binding of rifampicin to macromolecules. Xenobiotica 6 21-32 Boyd JF, Butcher BT, Stewart GT (1973) The nephrotoxic effect of cephaloridine and its polymers. Int J Clin Pharmacol Ther Toxicol 7 307-315 Brandt E, Gapp F, Knauseder F, Kuntscher H, Riedl K (1974) Untersuchungen iiber die Reinheit und Haltbarkeit von Natrium-Penicillin-G. Sci Pharm 42 209-221 Bruice TC, Bruice PY (1976) Solution chemistry of arene oxides. Accounts Chem Res 9 378-384... 

Two reactions dominate the chemistry of arene oxides the first which has been discussed above is their facile conversion to phenols and the second is their valence bond tautomerism to oxepins. Circumstantial evidence for the role of an aromatic epoxide type of intermediate (119) in the biosynthesis is provided by the location of two oxepin structural units in the related metabolite arantoin (113). The origin of these rings has been plausibly attributed to valence bond tautomerism of an L-phenylalanine epoxide Figure 4.18) and some experimental data to support this suggestion has been obtained by Brannon, Mabe, Molloy and Day . These workers showed that [ Hs]-L-phenylalanine was readily incorporated into acetylarantoin in Aspergillus terreus and contributed seven (or fourteen) hydrogen atoms to the molecule. In this case, in... 

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. 

Two comprehensive reviews of arene oxides-oxepins have been produced to date. The first review in 1967 dealt mainly with the concept of valence tautomerism in the monocyclic arene oxide-oxepin series, while the second article in 1973 also included the arene oxides of polycyclic aromatic hydrocarbons (PAH) and placed more emphasis upon their chemistry and biochemistry. In addition, a number of more speciahzed reviews dealing with aspects of arene oxide-oxepin chemistry including oxepins and hydrooxepins, solution chemistry, and roles in metabolism have appeared. The profusion of papers associated with the title arene oxides-oxepins that have appeared since 1973 (> 300 papers) allied to the significance of advances contained therein has prompted the present chapter. Particular stress is placed upon the material appearing during the period 1973-1982, with appropriate cross-references to the earlier literature. ... 

The most widely studied aspect of arene-oxide chemistry is the aromatization reaction to yield phenols. The acid-catalyzed, spontaneous, and thermal rearrangements of epoxides to ketones have a parallel in the isomerization of arene oxides to dienone intermediates with subsequent aromatization to phenols. Prior to their availability by chemical synthesis, arene oxides were postulated as initial inter-... 

Synthesis and Reactivities of Aromatic Oxides. Much of the work in this area is generated from an interest in the carcinogenicity of many of the fused-ring aromatic oxides. Some syntheses of arene oxides and the chemistry of diol epoxides have been reviewed. 

Interesting electrical properties are to be expected with the stepwise extension of this TT-system. The preparation of multilayered cyclophanes proved to be laborious [6] nevertheless new synthetic methods in transition metal chemistry of arenes have opened up a promising alternative approach via preparation of multidecker sandwich complexes (structure type D in Fig. 3). First row transition metals like chromium, iron and cobalt [51] form strong coordinative bonds with arenes when their oxidation state is low [48a] whereas second and third row elements like ruthenium, rhodium and iridium are strongly bonded towards arenes in higher oxidation states [48a, 51]. Sandwich complexes of cyclophanes can be divided into two groups ... 

A rational classification of reactions based on mechanistic considerations is essential for the better understanding of such a broad research field as that of the organic chemistry of Pd. Therefore, as was done in my previous book, the organic reactions of Pd are classified into stoichiometric and catalytic reactions. It is essential to form a Pd—C cr-bond for a synthetic reaction. The Pd— C (T-bond is formed in two ways depending on the substrates. ir-Bond formation from "unoxidized forms [1] of alkenes and arenes (simple alkenes and arenes) leads to stoichiometric reactions, and that from oxidized forms of alkenes and arenes (typically halides) leads to catalytic reactions. We first consider how these two reactions differ. 

The coordination chemistry of tertiary phosphine-functionalized calix[4]arenes have been described.279 Treatment of a bis(diphenylphosphino) or bis(dimethylphosphino) derivative of calix[4]arene with [PtCl2(COD)] leads to the formation of the corresponding dichloroplatinum(II) complex. The related diplatinum(II) species has also been reported with the tetrafunctionalized calix[4]arene.280 The mononuclear derivative is susceptible to oligomerization if the two free phosphine ligands are not oxidized or complexed to another metal center such as gold(I).279 The platinum(II) coordination chemistry of a mono-281 and diphosphite282 derived calix[ ]arene (n = 4 and 6, respectively) has also been described. 

Macrocycles containing isoxazoline or isoxazole ring systems, potential receptors in host—guest chemistry, have been prepared by multiple (double, triple or quadruple) 1,3-dipolar cycloadditions of nitrile oxides, (prepared in situ from hydroxamoyl chlorides) to bifunctional calixarenes, ethylene glycols, or silanes containing unsaturated ester or alkene moieties (453). This one-pot synthetic method has been readily extended to the preparation of different types of macrocycles such as cyclophanes, bis-calix[4]arenes and sila-macrocycles. The ring size of macrocycles can be controlled by appropriate choices of the nitrile oxide precursors and the bifunctional dipolarophiles. Multiple cycloadditive macrocy-clization is a potentially useful method for the synthesis of macrocycles. 

Examples of reductive cluster-opening and oxidative cluster-closing reactions are common in the chemistry of metal-hydrocarbon tt complexes. For example, bases convert nido- (hexa-hapto)arene-manganese tricarbonyl complexes into aracAno(pentahapto)-7T-cyclohexadienyl complexes 129,130, 217) ... 

Abstract This chapter covers one of the most important areas of Ru-catalysed oxidative chemistry. First, alkene oxidations are covered in which the double bond is not cleaved (3.1) epoxidation, cis-dihydroxylation, ketohydroxylation and miscellaneous non-cleavage reactions follow. The second section (3.2) concerns reactions in which C=C bond cleavage does occur (oxidation of alkenes to aldehydes, ketones or carboxylic acids), followed by a short survey of other alkene cleavage oxidations. Section 3.3 covers arene oxidations, and finally, in section 3.4, the corresponding topics for aUcyne oxidations are considered, most being cleavage reactions. 

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