A Forgotten Olefin: A Convenient One-pot Cascade Reaction Involving Suzuki-Miyaura and Mizoroki-Heck Couplings to Form (E)-1,2-Di(pyren-1-yl)ethylene

摘要

The addition of 0.5 equiv of vmylboronic acid pinacol ester I to 1-bromopyrene derivative 3 in the presence of [Pd(PPh3)4] and K2CO3 induced a cascade reaction involving Suzuki-Miyaura and Mizoroki-Heck couplings and afforded (E)-1,2-di(pyren-1-yl)ethylene derivative lb. An alternative synthesis of lb was carried out by an olefin metathesis. Formed lb showed absorption bands in the visible region and a low oxidation potential attributable to a narrow HOMO-LUMO gap.