Synthesis and resolution of 2-(diphenylphosphino)heptahelicene

Palladium catalysed Heck couplings have been applied to the two-step synthesis of a stilbene derivative bearing a diphenylphosphine oxide function which represents a suitable precursor for the photochemical generation of the corresponding [7]-helicene. After reduction of the phosphine oxide, resolution of the monodentate helical phosphine has been performed by means of the ortho-metallated (R)-1-(naphthyl)ethylamine–palladium complex. A ruthenium complex of (heptahelicen-2-yl)diphenylphosphine has also been prepared and fully characterized.