Aerobic oxidation of organic compounds catalyzed by vanadium compounds

Aerobic oxidation of α-hydroxy ketones catalyzed by dichloroethoxyoxovanadium in ethanol causes a carbon–carbon bond cleavage that produces diesters or diketones. This reaction is highly chemoselective, and disecondary glycols do not react at all. However, ditertiary glycols effectively react with dichloroethoxyoxovanadium or trichlorooxovanadium to provide the corresponding ketones. Aerobic oxidation of α-hydroxy ketones catalyzed by dichloroethoxyoxovanadium or trichlorooxovanadium in aprotic solvents almost quantitatively affords the corresponding α-diketones. The reaction of tertiary cyclopropanol compounds with vanadyl acetylacetonate under an oxygen atmosphere causes fragmentation of the cyclopropane moiety to produce β-hydroxy ketones and β-diketones. For the 6-substituted bicyclo[4.1.0]heptanol derivatives, the endoperoxides are also obtained together with β-hydroxy ketones. Conversely, 2-ethoxycarbonylcyclopropyl silyl ethers produce γ-oxocarboxylate derivatives given the same reaction conditions. Monothioacetals are easily deprotected into carbonyls using a catalytic amount of trichlorooxovanadium in 2,2,2-trifluoroethanol under an oxygen atmosphere. Thiols are converted into the corresponding disulfides by the aerobic oxidation catalyzed by trichlorooxovanadium in the presence of molecular sieves 3A. Polymer-supported vanadium compounds are synthesized by the reaction of vanadium oxytrichloride with polymers bearing hydroxyl moieties. The catalyst prepared from TentaGel S OH was highly active and reusable for the aerobic oxidations.     

Furan compounds

A method for obtaining 2-aryl derivatives of 4,7-dihydro- and 4,5,6,7-tetrahydroisoindoles from the products of the diene synthesis of 2,5-dimethoxy-2,5-dihydrofuran with aliphatic and cylic dienes is described.See [1] for Communication XLIII.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1443–1445, November, 1970.     

Nitrogen-fluorine compounds

The experimental and theoretical chemistry of nitrogen-fluorine compounds is an area that has seen considerable renaissance over the past decade. This review is not exhaustive in scope but rather focuses on and highlights certain aspects in this field. In particular (but not exclusively), the chemistry of binary N-F species is discussed.     

Alkoxy compounds

Six 2, 2, 5-trialkyl-5-α-alkoxyethyl-1, 3-dioxanes have been synthesized for the first time by the condensation of 2-alkyl-2-α-alkoxyethyl-1, 3-propane diols with ketones, and it has been shown by a study of their PMR spectra that they exist in the unsymmetrical boat conformation. The PMR spectra of a number of previously-synthesized 2-alkyl(aryl)-5-alkyl-5-α-alkoxyethyl-1, 3-dioxanes have been considered and it has been shown that from an analysis of the spectra it is possible to estimate the contents of geometrical isomers in a mixture. The stereochemistry of these compounds has been discussed.     

Organoboron compounds

Summary Treatment of alkaneboronic eaters with alkyllithiums yields dialkylborinic esters.