Oxidation with elimination

Taylor and colleagues discovered recently that IV-aryl malonamides or cyanoacetamides 312 cyclized in 53-92% yield to oxindole-3-carboxylates 313 in the presence of 5 mol% of Cu(OAc)2 using air as the stoichiometric reoxidant for the catalyst (Fig. 83) [412]. The reactions occur likely by initial formation of a copper enolate of 312. SET oxidation with elimination of CuOAc gives radical 312A, which undergoes a 5-exo cyclization to the aryl unit. A final oxidative... 

Protonolysis reactions of alkoxides and aryloxides are common one example is hydrolysis of the metal alkoxide, giving metal oxide with elimination of the alcohol. Although the aim is often to avoid such a reaction, it is of great interest in the deposition of high-purity metal oxides, which are used in areas such as optoelectronics, high f superconductors, and advanced ceramics. ... 

The degradation of 2-chlorobenzoic acid by P. cepacia also involves removal of the chlorine substituents in the first step [121,122], but here the aromatic ring undergoes oxidation with elimination of CO,. Catechol, which is the first intermediate of this metaboHc pathway, is further degraded by an ortho-cleavage pathway. A metabolic pathway for the degradation of 3-chlorobenzoic acid by Pseudomonas sp. B13 is shown in Figure 4. Zaitsev and Baskunov [123] reported a similar scheme for the metabolism of 3-chlorobenzoic acid in Acinetobacter calcoaceticus. 

Lithium Iodide. Lithium iodide [10377-51 -2/, Lil, is the most difficult lithium halide to prepare and has few appHcations. Aqueous solutions of the salt can be prepared by carehil neutralization of hydroiodic acid with lithium carbonate or lithium hydroxide. Concentration of the aqueous solution leads successively to the trihydrate [7790-22-9] dihydrate [17023-25-5] and monohydrate [17023-24 ] which melt congmendy at 75, 79, and 130°C, respectively. The anhydrous salt can be obtained by carehil removal of water under vacuum, but because of the strong tendency to oxidize and eliminate iodine which occurs on heating the salt ia air, it is often prepared from reactions of lithium metal or lithium hydride with iodine ia organic solvents. The salt is extremely soluble ia water (62.6 wt % at 25°C) (59) and the solutions have extremely low vapor pressures (60). Lithium iodide is used as an electrolyte ia selected lithium battery appHcations, where it is formed in situ from reaction of lithium metal with iodine. It can also be a component of low melting molten salts and as a catalyst ia aldol condensations. 

Trimethyl aluminum and propylene oxide form a mixture of 2-methyl-1-propanol and 2-butanol (105). Triethyl aluminum yields products of 2-methyl-1-butanol and 2-pentanol (106). The ratio of products is determined by the ratio of reactants. Hydrolysis of the products of methyl aluminum dichloride and propylene oxide results ia 2-methylpropeae and 2-butene, with elimination of methane (105). Numerous other nucleophilic (107) and electrophilic (108) reactions of propylene oxide have been described ia the Hterature. 

Alcohols react with boric acid with elimination of water to form borate esters, B(OR)3. A wide variety of borate salts and complexes have been prepared by the reaction of boric acid and inorganic bases, amines, and heavy-metal cations or oxyanions (44,45). Fusion with metal oxides yields... 

Trace impurities in the feed streams can lead to combination of an oxidant with a flammable material (e.g. acetylene in liquid oxygen, solid oxygen in liquid hydrogen) and precautions must be taken to eliminate them. 

Peroxvaad oxidation of bridged 5,6,7,8-tetrafluoro 1 4-dihydronaphthalene-1,4 imines gives aromatic fluorohydrocarbons by elimination of the imine bridge [91] (equation 84) Almost the same yields are achieved by oxidation with 30% hydrogen peroxide m refluxing methanol [91]... 

The intermediacy of dipolar species such as 186 has been demonstrated by reaction of enamines with 2-hydroxy-1-aldehydes of the aromatic series (129). The enamine (113) reacts in benzene solution at room temperature with 2-hydroxy-1-naphthaldehyde to give the crystalline adduct (188) in 91 % yield. Oxidation with chromium trioxide-pyridine of 188 gave 189 with p elimination of the morpholine moiety. Palladium on charcoal dehydrogenation of 189 gave the known 1,2-benzoxanthone (129). 

This group is stable to TEA and morpholine in pyridine at 20°. It is cleaved by oxidation with MCPBA followed by elimination with TEA in Pyr, 10 min, 20°." The rate of cleavage is proportional to the strength of the electron-withdrawing group on the phenyl ring. ... 

In addition to having typical A -oxide reactions, quinazoline 3-oxide also shows the same reactivity as quinazoline toward nucleophilic reagents, but the reaction goes a step further by eliminating water as shown in reaction 2d. Oxidation with hydrogen peroxide... 

The reaetion of 4-dialkylamino(alkoxy)but-3-en-2-one with benzonitrile N-oxide (35°C, EtaO, 8 h) follows a seheme of 1,3-dipolar eyeloaddition with elimination of ammonia, the eorresponding amine, or aleohol to form 3-phenyl-4-aeetylisoxazole 324 in 60-67% yield (83ZOR2281). 

By oxidation with chromic acid, this is converted into cyclohexanone-3-carboxylic acid, in which the —CH. OH— group is converted into the —CO— group. This is converted into its ethyl ester and treated with magnesium methyl iodide, and the product, on hydrolysis, yields l-methyl-cyclohexane-l-ol-3-carboxylic acid, which is converted byhydro-bromic acid into 1-bromo-l - methyl - cyclohexane - 3 - carboxylic acid. When this is digested with pyridine, hydrobromic acid is eliminated and yields l-methyl-A -cyclohexane-3-carboxylic acid of the formula—... 

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