Some reactions of 2-(2-hydroxyhexafluoro)isopropyl-5-methylfuran

The bromination of 2-(2-hydroxyhexafluoro)isopropyl-5-methylfuran at the methyl group and subsequent reaction with nitrogen nucleophiles gave some secondary amines and quaternary salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1308–1311, October, 1992.     

Plant-protection agents based on compounds of the pyridine series (review)

The principal derivatives of pyridine bases that display pesticide activity are examined. It is shown that the accessible oxygen-containing functional derivatives of pyridine are intermediates for the synthesis of a large number of promising plant-protection agents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 579–587, May, 1989.     

Thermal Dehydrogenation of Base‐Stabilized B2H5+ Complexes and Its Role in CH Borylation

Thermally induced dehydrogenation of the H‐bridged cation L₂B₂H₅⁺ (L=Lewis base) is proposed to be the key step in the intramolecular C? H borylation of tertiary amine boranes activated with catalytic amounts of strong “hydridophiles”. Loss of H₂ from L₂B₂H₅⁺ generates the highly reactive cation L₂B₂H₃⁺, which in its sp²‐sp³ diborane(4) form then undergoes either an intramolecular C? H insertion with B? B bond cleavage, or captures BH₃ to produce L₂B₃H₆⁺. The effect of the counterion stability on the outcome of the reaction is illustrated by formation of LBH₂C₆F₅ complexes through disproportionation of L₂B₂H₅⁺ HB(C₆F₅)₃^?.     

N-Directed aliphatic C-H borylation using borenium cation equivalents

Highly electrophilic boron cations derived from hindered amine borane complexes have been shown to undergo intramolecular aliphatic C-H borylation.     

Vapor-phase catalytic oxidation of aβ-picoline fraction

The vapor-phase catalytic oxidation with atmospheric oxidation of a -picoline fraction consisting of a mixture of 3- and 4-methylpyridines and 2,6-lutidine containing small amounts of 2-methylpyridine and pyridine has been studied. On a vanadium oxide catalyst at 440° C with a contact time of 1.2 sec and a molar ratio of oxygen to steam to methylpyridine of 7 54 1, a high degree of conversion of the 4-methylpyridine and the 2,6-lutidine into pyridine-4-aldehyde and 6-methylpyridine-2-aldehyde, respectively, has been achieved. The main component of the aqueous solution of the catalyzate (after the isolation of thepyridine aldehydes in the form of oximes) is 3-methylpyridine.     

A statistical study of the informational base of biologically active pyridine compounds

A computer analysis of the literature material clarified the types of activity most characteristic for pyridine derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 109–113, January, 1985.     

Vinylogs of 4-pyridinaldehyde

Condensation of 4-pyridinaldehyde and 3-(4-pyridyl)acrolein with acetaldehyde in the presence of morpholine acetate has given their vinylogs. These compounds have been shown to exist mainly in the trans-configurations.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 77–80, January, 1991.     

Vapor phase oxidation of 2-methylpyridine on vanadyl polyphosphates

Vanadyl -and -polyphosphates in vapor phase oxidation of 2-methylpyridine show comparable activity and selectivity to the formation of pyridine-2-carboxaldehyde as traditional vanadium-molybdeum oxide catalysts. A redox mechanism for the reaction of 2-methylpyridine oxidation on vanadyl polyphosphates is suggested with interaction between 2-methylpyridine and oxygen of the catalyst lattice as the rate-determining step.

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- - 2- -- . - 2- . - 2- .

     

Reactivity of isomeric pyridinecarboxaldehydes in catalyic hydrogenation

It has been established by a quantum-chemical method (CNDO/2) that there are two possible mechanisms occurring in the vapor phase hydrogenation of 2-, 3-, and 4-pyridinecarboxaldehydes in the presence of a copper-chromium catalyst at 180-300°C. One of these involves a donor-acceptor interaction of aldehyde with catalyst and the addition of hydrogen to the carbon atom of the carbonyl group at the first stage. The second possible mechanism is the synchronous addition of hydrogen to the carbon and oxygen of the carbonyl group of a weakly bound a aldehyde molecule with an unchanged electronic structure.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1082–1086, August, 1994.