Arylic oxidation

Chichibabin reaction, 5, 409-410 sulfonation, 5, 429 synthesis, 5, 160, 161, 457-498, 496 tautomerism, 5, 365 toxicity, 1, 139 UV spectra, 5, 356, 357 2H-Benzimidazoles 3,3-dioxides synthesis, 6, 407 2V,7ST-dioxides reactions, 5, 456 Benzimidazoles, aryl-oxidation, 5, 433 Benzimidazoles, nitro-mass spectra, 5, 359 reduction, 5, 441 Benzimidazole-2-sulfonic acids reactions... 

By this method, different classes of PNs were prepared by replacing chlorine atoms of the polydichlorophosphazene intermediate by primary or secondary amines, alkoxide or aryl-oxide, or organ metallic reagents. " ... 

Further insight into the carbon-oxygen reductive elimination from Pt(IV) and the involvement of five-coordinate Pt(IV) intermediates has been provided recently. The first direct observation of high-yield C-0 reductive elimination from Pt(IV) was described and studied in detail (50,51). Carbon-oxygen coupling to form methyl carboxylates and methyl aryl ethers was observed upon thermolysis of the Pt(IV) complexes ( P2 )PtMe3(OR) ( P2 =bis(diphenylphosphino)ethane or o-bis(diphenyl-phosphino)benzene OR=carboxylate, aryl oxide). As shown in Scheme 47, competitive C-C reductive elimination to form ethane was also observed. 

Arnold et alP reported the synthesis and structural characterization of an aryl-oxide-functionalized samarium silsesquioxane complex. Steric protection of 2 by one SiMe2tBu group generated a new disilanol ligand, (c-C5H9)7Si709(0H)2(0SiMe2tBu)... 

These results show that nucleophilic catalysis predominates when the leaving group is less basic than acetate, or of comparable basicity. Where the aryl-oxide is more than about 3 pK units more basic, however, the nucleophilic mechanism becomes insignificant. And for p-nitrophenyl acetate, which appears to lie close to the borderline, nucleophilic and general base catalysis proceed at comparable rates. 

The formation of a sol-gel porous material is through a hydrolysis-polycondensation reaction. An example is given in equation 1 with the methoxide of silicon (tetramethyl-orthosilicate, TMOS), but many other alkoxides, aryl oxides and acyl oxides can be used, as well as Si—N and Si—Cl compounds. 

This complex exhibits only modest activity in the catalytic hydrogenation of 1-hex-ene (3 turnovers/hr at 1 atm), in a dilference from other aryl oxide-based hydrido derivatives as effective arene hydrogenation catalysts [422], Similar alkoxide tetra-hydroborate complexes of U(IV) complexes are reported [423]. 

By appropriate choice of the reactants and the reaction conditions, a phenol-substituted carboxylic acid may react with an organotin compound to give both an organotin ester and an organotin aryl oxide within the same molecule. The reaction of trimethyltin chloride with 4-hydroxy-3-methoxybenzoic acid (HVAH) in the presence of water and pyridine at 130 °C in a sealed tube gave the unique two-dimensional coordination polymer 134 (equation 2)286. 

Neodymium-alcoholates were mentioned in the patent literature prior to Nd-carboxylates [37,38,224-228]. The Nd-alcoholates most frequently mentioned in literature comprise Nd(OBu)3 [224,225,229,230], Nd(0 Pr)3 [231-233], and Nd aryl oxides [185,234,235] (Scheme 3). Also adduct compounds... 

Like the amide derivatives (see Sect. 6), rare-earth metal alkoxide (aryl-oxide) complexes Ln(()R)x are pseudo-organometallics exhibiting a Ln-... 

Binary neodymium alk(aryl)oxide/dialkylmagnesium diene polymerization catalysts were reported by J.-F. Carpentier and coworkers [181,192], The homopolymerization of butadiene, and copolymerization with styrene and... 

Crucially, discrete Ln/Al organometallics were unambiguously identified as intermediates of the commercially applied neodymium-based diene polymerization and subsequently employed in binary initiator mixtures. Particularly for the industrially relevant O-only bonded carboxylate- and alk(aryl)oxide rare-earth metal components, the use of pre-alkylated Ln derivatives developed into valuable structure-reactivity relationships partially uncovering the blackbox, which is provided by ternary Ziegler Misch-katalysatoren. Accordingly, rare-earth metal centers provide a unique stereo-... 

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