Quantum - Chemical Study of the Relation Between Electronic Structure and IR Spectra of Neutral Molecules,Anion - Radicals,and Dianions of Aromatic Nitriles

The relation between the IR data and the quantum-chemical indices. calculated by the CNDO/2 method has been studied. The linear relationship between the experimentally measured °C≡N and the corresponding Wiberg bond index (W_C≡N) has been found for the series of conjugated nitriles including neutral molecules. anion - radicals and dianions.

The changes in the intensity of the stretching C≡N vibration on transition from a neutral molecule into anion - radical and dianion have been investigated by the CNDO/2 method. The calculated values for δμ/δQ_CN show that in the order: neutral molecule, anion - radical and dianion the IR intensity of the stretching C≡N vibration significantly increases.     

Nitrile Synthesis with Aldoxime Dehydratases: A Biocatalytic Platform with Applications in Asymmetric Synthesis,Bulk Chemicals,and Biorefineries

Nitriles comprise a broad group of chemicals that are currently being industrially produced and used in fine chemicals and pharmaceuticals, as well as in bulk applications, polymer chemistry, solvents, etc. Aldoxime dehydratases catalyze the cyanide-free synthesis of nitriles starting from aldoximes under mild conditions, holding potential to become sustainable alternatives for industrial processes. Different aldoxime dehydratases accept a broad range of aldoximes with impressive high substrate loadings of up to >1 Kg L⁻¹ and can efficiently catalyze the reaction in aqueous media as well as in non-aqueous systems, such as organic solvents and solvent-free (neat substrates). This paper provides an overview of the recent developments in this field with emphasis on strategies that may be of relevance for industry and sustainability. When possible, potential links to biorefineries and to the use of biogenic raw materials are discussed.     

Synthesis of nitriles from acetonitrile and methanol in the presence of oxide catalysts

The promoting effect of potassium included in Cr/MgO catalysts for the synthesis of nitriles from acetonitrile and methanol was found. The 5% Cr-0.5% K/MgO catalyst exhibited the highest activity in the synthesis of nitriles. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1540–1542, August, 1997.     

Spectroscopic Calculation of CH Bond Dissociation Energies for Aliphatic Nitriles

The CH bond dissociation energies were calculated spectroscopically for acetonitrile, propionitrile, isobutyronitrile, and trimethylacetonitrile from the fundamental absorption bands in the anharmonic approximation using the variational technique with the Morse-harmonic basis set. A similar calculation was carried out for various associates of acetonitrile. Due to this, CH bond dissociation energies were determined for the liquid state of acetonitrile.Original Russian Text Copyright © 2004 by L. A. Gribov, I. A. Novakov, A. I. Pavlyuchko, V. V. Korolkov, and B. S. Orlinson__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 816–821, September–October, 2004.     

Trimethylsilylcyanation of Heterocyclic Aldimines - Derivatives of 2-Trifluoromethylaniline

The addition of trimethylsilyl cyanide to the CH=N bond of furan, thiophene, and pyridine azomethines in the presence of aluminum bromide as catalyst was studied. The effect of the CF₃ group in the aldimines produced by the condensation of O-, S-, and N-heteroaromatic aldehydes with 2-trifluoromethylaniline on the reaction and also other relationships of the investigated processes were studied. The corresponding furan, thiophene, and pyridine -amino nitriles were synthesized.     

An investigation of the mesogenic properties of dibenzoquinoxaline derivatives

The syntheses of two new discotic molecules based on the dibenzoquinoxaline core are reported; comparison of their phase behaviors to a known dinitrile compound demonstrates the importance of specific functional groups in stabilizing columnar mesophases.     

Electroreduction of Nitriles: The Reduction of Furfurylidene- and Benzylidenemalonodinitriles and Esters of Substituted 1-Cyanoacrylic Acids

The electrochemical reduction of compounds with a common formula R¹(H)C=C(CN)R², where R¹ is C₆H₅, n-CH₃OC₆H₄, n-FC₆H₄, or -furyl; and R² is CN or COOC₂H₅ is studied. The reduction of these compounds at a zinc cathode in the water–acetonitrile KH₂PO₄ solution yields both cyclic and linear hydrodimers. The relative yield of the linear hydrodimer increases with lowering the temperature and acetonitrile content in the catholyte. The obtained data well correlate with the suggestion that the cyclic products form in the catholyte bulk from linear hydrodimers.     

Reactions of 1,3,3-trimethyl-3,4-dihydroisoquinolines with polyhaloalkanonitriles

The reactions of 1,3,3-trimethyl-3,4-dihydroisoquinolines with halogenated nitriles afford -aminovinylimines, which undergo acid hydrolysis to form 1-(polyhaloacylmethylene)-3,3-dimethyl-3,4-dihydroisoquinolines.