Condensation of isophorone and isophorone oxime with amines and aldehydes

Mannich condensations of isophorone (3,5,5-trimethylcyclohex-2-en-1-one) with paraformaldehyde and dimethylamine, benzylamine, and piperidine hydrochlorides were studied. The reactions were not selective, and they involved both activated methylene group and vinylic carbon atom, as well the exocyclic methyl group at the double bond. The corresponding isomeric amino ketones were formed in comparable amounts (42, 30, and 28%). The E and Z isomers of isophorone oxime reacted with paraformaldehyde and dimethylamine hydrochlride to give mixtures of analogous Mannich condensation products, but the fraction of the addition product at the carbon atom spatially close to the oxime hydroxy group was larger. Under analogous conditions, the reaction of isophorone with aromatic amines and aromatic aldehydes gave products of two-component condensation of isophorone with aldehydes, and the reactions involved exclusively the activated methylene group in the initial enone with formation of the corresponding trans,trans-isomeric 7-arylmethylidene derivatives.     

Thiobenzophenone and tetracyanoethylene

The title reaction furnished the yellow 3,4-dicyano-2,5-bis(diphenylmethyleneamino)-thiophene and a red precursor which contains one more sulfur atom; structures and mechanism are discussed.     

Molecular associations between indolizines and tetracyanoethylene

Spectroscopic, thermodynamic and kinetic properties of molecular interactions between indolizines and tetracyanoethylene are reported. The interactions involved in the complexes are weak as evidenced by the low formation constants. The kinetic behaviour indicates the initial formation of a pI-complex that is rapidly transformed into a σ-complex and thereafter into the final adduct(s). Apart from the results obtained by other techniques, infrared data clearly evidence vibrational contributes characteristic of the complexes, the tricyanovinyl derivatives and the tetracyanoethylene radical anion.     

Lattice dynamics of tetracyanoethylene

Lattice dynamics calculations for both crystalline forms of tetracyanoethylene are presented. The comparison of the calculated static and dynamical properties with the experimental data, leads us to suggest an improved parameter set for the “6-exp” potential function for crystals with cyano groups.     

Metal-acetylide addition to tetracyanoethylene

Two push-pull chromophores that have shown utility in the field of molecular electronics and non-linear optics are DDMEBT (1, 2-(4-dimethylamino)phenyl)-3-((4-(dimethylamino)phenyl)ethynyl)buta-1,3-diene-1,1,4,4-tetracarbonitrile) and TDMEE (2, 4-(4-dimethylamino)phenyl)but-1-en-3-yne-1,1,2-tricarbonitrile). Unfortunately, the methods reported for their synthesis give variable yields, use toxic solvents, and only provide small amounts of material. We report improved synthetic protocols, providing access to larger quantities of material. By investigating multiple metal-acetylides of 4-ethynyl-N,N-dimethylaniline and their subsequent addition to TCNE, we obtained various products depending on the identity of the metal ion. This led to the simple synthesis of push-pull chromophoric compounds.     

Reactions of primary amines with tetracyanoethylene

Primary amines, 3-triethoxysilylpropylamine, 3-silatranylpropylamine, and cyclohexylamine, react with tetracyanoethylene in acetonitrile at room temperature via addition at the cyano group to afford the corresponding amidines. N-Cyclohexyltricyanoacrylamidine exists as a mixture of two of the three possible isomers, while N-(3-triethoxysilylpropyl)tricyanoacrylamidine and N-(3-silatranylpropyl)tricyanoacrylamidine exist mainly as a single isomer containing NH₂ group. N-(3-Triethoxysilylpropyl)tricyanoacrylamidine was used to prepare gels and films.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1308–1314.Original Russian Text Copyright © 2004 by Ladilina, Semenov, Kurskii, Khorshev, Domrachev.     

Structural and spectral characteristics of the electrogenerated tetracyanoethylene dianion

Structural and spectral characteristics of the electrogenerated tetracyanoethylene dianion (TCNE2-) were experimentally and theoretically examined. Spectroelectrochemistry of TCNE gives the spectra of TCNE2- in CH3CN at 220 nm, and in CH2Cl2 at 300 nm. These spectral characteristics are well explained by CIS/6-31G(d) and semiempirical CNDO/S-CI calculations. The bands in CH3CN and in CH2Cl2 are assigned to the degenerate 1E<--1A1 transition at the D2d structure and the 1B2u<--1Ag transition at the D2h structure, respectively. The rotation barrier of the C=C bond in TCNE2- is estimated by Hartree-Fock (HF), second-order M?ller-Plesset perturbation (MP2) and fourth-order MP (MP4) calculations with 6-31G(d), 6-31+G(d) and 6-311+G(d) basis sets as 42-51 kJ mol(-1). The D2d structure is most stable, and the D2h structure represents the transition state of the internal rotation. The calculations reveal that the two-electron addition to the antibonding LUMO of TCNE causes an easy rotation around the C=C bond of TCNE2- characterized by the formal single bond. These results show that TCNE2- preferentially adopts D2d and D2h structures in solvents depending upon the solvent nature by virtue of the easy rotation around the C=C bond.     

The reaction of indolizines with tetracyanoethylene

Tetracyanoethylene (TCNE) reacts with indolizines ( 1a-c ) to give mixtures of 1- and 3-sub-stituted tricyanovinylindolizines, respectively. The isomers are identified by nmr spectroscopy. The occurrence of intramolecular charge-transfer bands in the visible spectra is discussed.     

Reaction of 1-vinylpyrazoles with tetracyanoethylene

It was shown that in the reaction of tetracyanoethylene with 1-vinylpyrazoles in aprotic solvents, one of the first stages involves the formation of - complexes. The final products of the reaction are 1-(2,2,3,3-tetracyano-1-cyclobutyl)pyrazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 924–926, July, 1989.     

Reactions of tetracyanoethylene with polyenes]

Reactions of tetracyanoethylene with polyenes have been studied. With vitamin A derivatives 7,10- and 11,14-cycloadducts were formed. Starting with the unsaturated dihydroxy compound 13 tetracyanoethylene first catalyzed the ring closure to give the dihydrofuran 14 which then was dehydrogenated to the corresponding furan 15 .     

Molecular complexes of aromatic N-oxides with tetracyanoethylene

Donor—acceptor interaction of tetracyanoethylene with aromatic N-oxides leads to the formation of two kinds of molecular complexes of the ,-type: -complexes and charge-transfer complexes. A correlation is observed between the reactivity of the N-oxides and the electronic properties of the substituents in the N-oxides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 488–492, April, 1991.     

Reactions of pregnenolone and 16-dehydropregnenolone acetate with tetracyanoethylene

Russian Journal of Organic Chemistry -     

Electroconductive polypyrrole doped with tetracyanoethylene anion radicals

An electroconductive polymer doped with tetracyanoethylene anion radicals was obtained by chemical oxidation of undoped polypyrrole. Its electronic absorption spectra were investigated. Broadening of the line of the EPR spectrum was observed when the anion radical was introduced into the polymer; this may be due to slow spin-spin exchange between the radical and the polar chain of the polymer.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 3, pp. 260–263, May–June, 1993.This research was financed by the State Committee of Ukraine for Problems in Science and Technology from fundamental-research.