Putting a B in Polymer

Significance

Bis[B-(trimethylsilylethynyl)borinato]-iron(II) complex 1 was prepared by the Fu method from trimethylphosphine adduct of borabenzene in a two-step, one-pot procedure. A smooth deprotection was accomplished with tetrabutyl­ammonium fluoride adsorbed on silica gel. The ­resulting alkynylboratabenzene complex 2 is surprisingly stable, and it proved to be a versatile building block for polymeric materials. Polymerization via Sonogashira coupling and azide-alkyne cycloaddition with appropriate co-monomers gave soluble, high-molecular weight, film-forming polymers 3 and 4 in high yield.