1-Aryl-F-1,3-butadienes and Unsymmetrical alpha,omega-Diaryl-F-polyenes.
Para-substituted 1-aryl-F-1,3-butadiene derivatives p-R-C(6)H(4)-CF=CFCF=CF(2) (2a-g), where R = H, CH(3), OCH(3), OC(6)H(11), N(CH(3))(2), Br, and CF(3), have been prepared by reaction of appropriate arylmagnesium bromides with F-1,3-butadiene. (19)F NMR chemical shifts correlate with sigma(p) Hammett substituent constants. Compounds 2a-e react on their terminal perfluorovinyl group with C-nucleophiles and were used as intermediates in subsequent reactions with suitable organolithium compounds for the synthesis of a new series of unsymmetrically substituted alpha,omega-diaryl-F-polyenes RC(6)H(4)(CF=CF)(n)()C(6)H(4)R', where n = 2 or 3 and R' is one of the substituents specified above. A variety of new synthons containing alpha,omega-diaryl-F-1,3-butadiene skeleton and reactive Br, OH, CH=O, and COOH functionalities in para-positions on aromatic rings has been also prepared. Structural aspects, NMR spectra, and mesogenic properties of the title compounds are discussed.
Shtarev
Alexander B.
AB
Department of Organic Chemistry, Institute of Chemical Technology, Technická 5, Prague 6, CZ-166 28, Czech Republic.
Kremlev
Mikhail M.
MM
Chvátal
Zdenek
Z