One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

Abstract

SummaryA convenient one-pot approach to alkylcyanobiaryls is described. The method is based on biaryl cross-coupling between the sodium salt of the terephthalonitrile dianion and a neutral aromatic nitrile in liquid ammonia, and successive alkylation of the long-lived anionic intermediate with alkyl bromides. The reaction is compatible with benzonitriles that contain methyl, methoxy and phenyl groups, fluorine atoms, and a 1-cyanonaphthalene residue. The variety of ω-substituted alkyl bromides, including an extra bromine atom, a double bond, cyano and ester groups, as well as a 1,3-dioxane fragment are suitable as alkylation reagents.

Electro-optical effect of the nCOOCB liquid crystal molecules under the terahertz frequency range: A theoretical approach

“…The molecular packing and intermolecular forces are affected by the cause of charge distribution of the whole molecule. 3,4 The alkoxy and alkylamino biphenyl groups are mostly having higher nematic to isotropic (N-I) transition temperature in comparison with the alkyl derivates. The alkoxy and alkylamino biphenyl groups enhance the N-I transition temperature due to the electron-donating behaviour, and hence the molecular charge and polarizability are increased by the LC.…”

“…The 8OCB LC reveals the anti-ferroelectric effect. 11,12 The OCB LC enhances the N-I transition temperature for the even members (2,4,6,8) and reduces the N-I transition temperature for the odd members (1, 3, 5, 7).…”

Radical Anions of Aromatic Carbonitriles as Reagents for Arylation of Fluorinated Benzonitriles

“…2,3 That is why alkylation occurs at the ipso-or unsubstituted (predominantly para-) position of the aromatic fragment, thus producing alkylarenes, alkylcyanoarenes, or dihydro derivatives in good to high yields. 1 In addition to the high productivity of cyanoarenes in the Birch reductive alkylation, we uncovered the possibility of arylation of neutral aromatic substrates (benzonitrile, 4 tolunitrile, methoxy-and fluorobenzonitrile, 5,6 or 2-and 3-cyanobiphenyl 7 ) with terephthalonitrile dianion 1 2− . The coupling of dianion 1 2− with neutral cyanoarenes proceeded predominantly as a nucleophilic substitution of the substrate para-hydrogen atom with the p-cyanophenyl moiety of dianion (S N H) and/ or one-electron transfer followed by recombination of radical anions in a primary cage (ET).…”