The synthesis and chemistry of 1,2,3,4,5-pentafluorochromarene; Electronic effect of a π-Cr(C6H6) moiety

(C6F5H)Cr(C6H6), which is synthesisable by the metal atom cocondensation procedure, can be metallated at −75°C using BuLi and is thus readily functionalisable. Infrared spectroscopic evidence suggests that a π-Cr(C6H6) moiety is an electron-donating substituent. Attempts to produce the benzyne π-complex (C6F4)Cr(C6H6) were unsuccessful and led to bichromarene formation. 1,2,3,5- and 1,2,4,5-tetrafluorochromarenes have also been synthesised and their potential for incorporation into polymers is discussed.