A synthetic strategy leading to monodisperse PPV oligomers by coupling reactions of vinyltrimethylsilanes

A novel strategy for the synthesis of well-defined oligo(phenylenevinylene)s was developed. The procedure is entirely based upon two coupling processes, both involving vinyltrimethylsilanes. Bis-(styryl)benzenes 2a-g bearing two octyloxy groups in the central aromatic ring and various substituents on the external aromatic rings were prepared in good yield by a regio- and stereoselective coupling reaction of 1 with different arenediazonium tetrafluoroborates. Oligomers with a more extended conjugated system, 4a-c, and with m-phenylene subunits 13a,b, were also readily obtained by conversion of the unsaturated trimethylsilyl derivatives 3a,c,d to the corresponding boron derivatives and a subsequent coupling reaction with compounds 2a and 2c.