Synthesis of 9,10-bis(trifluoromethyl)benzobarrelenes through reaction of hexafluorobut-2-yne and substituted naphthalenes

Mikhail M. Kremlev, Oleksii I. Mushta, Yurii L. Yagupolskii, Julia A. Rusanova, Sheng Peng, Viacheslav Petrov. [Display omitted] •9,10-Bis(trifluoromethyl)benzobarrelenes formed by cycloaddition of hexafluorobut-2-yne with substituted naphthalenes.•Formation of two isomeric products derived from cycloaddition of HFB to different aromatic rings of the naphthalene system.•9,10-Bis(trifluoromethyl)benzobarrelenes carboxylic acids and esters obtained. The cycloadducts 9,10-bis(trifluoromethyl)benzobarrelenes were prepared by the reaction of hexafluorobut-2-yne (HFB) with 1- and, 2- substituted naphthalenes in moderate to high yields. In most cases the reaction proceeds with the formation of two isomeric products derived from cycloaddition of HFB to different aromatic rings of the naphthalene system. The individual isomers were isolated by column chromatography and fully characterized. The basic hydrolysis of ester derivatives of the various 9,10-bis(trifluoromethyl)benzobarrelenes provided the corresponding acids.