Iridium-catalyzed dehydrogenative silylation of azulenes based on regioselective C-H bond activation.

Use of an iridium catalyst allowed the efficient dehydrogenative functionalization of C-H bonds of azulenes with the production of hydrogen as the sole byproduct. The reaction occurred with excellent chemo- and regioselectivities to provide 2-silylazulenes even without any directing groups. Effective conjugation through the 2-position of the azulene ring was demonstrated by the unique stimuli-responsiveness against an acid-base reaction.