Abstract: The interaction of terephthalonitrile (1) dianion (1(2-)) with benzonitrile (2) or m-tolunitrile (3) provides 4,4'-dicyanobiphenyl (4) or 4,4'-dicyano-2-methylbiphenyl (5), respectively. This result shows that dianion 12- serves as a reagent for p-cyanophenylation of aromatic nitriles. Based on experimental data, such as the chemical trapping of the 4,4'-dicyanobiphenyl precursor 4-cyano-1-(p-cyanophenyl)cyclohexa-2,5-dienyl anion (7) and the failure to obtain biphenyl 4 through the interaction of independently generated radical anions (RAs) 1(-) and 2(-), as well as on the results of quantum-chemical calculations, a mechanism is suggested that includes a charge-transfer complex (CTC) between 1(2-) and the aromatic nitrile as the key intermediate. The formation of this CTC is followed either by an intracomplex electron transfer (ET) and recombination of terephthalonitrile and aromatic nitrile RAs within an unequilibrated RA pair, or by synchronous ET and bonding of the ipso-carbon atom of terephthalonitrile with the p-carbon atom of the aromatic nitrile. The synthetic significance of p-cyanophenylation of arenecarbonitriles by dianion 1(2-) is illustrated by the high yield of biphenyl product 4 (approx. 90%) as well as by the possibility of a one-pot synthesis of 4-butyl-4'-cyanobiphenyl and 4-butyl-4'-cyano-2-methylbiphenyl by successive treatment of dianion 1(2-) with nitrile 2 or 3 and butyl bromide. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).

Cite: Panteleeva E. , Shchegoleva L. , Vysotsky V. , Pokrovsky L. , Shteingarts V.
Reductive activation of arenes, XVIII. Cyanophenylation of aromatic nitrites by terephthalonitrile dianion: Is the charge-transfer complex a key intermediate?
European Journal of Organic Chemistry. 2005. V.2005. N12. P.2558-2565. DOI: 10.1002/ejoc.200400851 WOS Scopus РИНЦ

Dates:

Published print:

Jun 1, 2005

Identifiers:

Web of science	WOS:000229947200014
Scopus	2-s2.0-20744455827
Elibrary	13479662
OpenAlex	W2077993828

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