Abstract
While normally reluctant toward oxidation, SbBr(3) can be oxidized with 3,4,5,6-tetrachloro-1,2-benzoquinone (o-chloranil) in the presence of a Lewis base like the bromide anion or triphenylphosphine oxide (PPh(3)O) to form the tetrachlorocatecholate (cat(Cl)) derivatives [SbBr(4)(cat(Cl))](-) ([2-Br](-)) and SbBr(3)(cat(Cl))•OPPh(3) (2•OPPh(3)), respectively. Structural, spectroscopic, and computational data indicate that the SbBr(3)(cat(Cl)) fragment is similarly, if slightly less, Lewis acidic than the previously reported SbCl(3)(cat(Cl)) fragment. The SbBr(3)/o-chloranil system, as well as its previously reported counterpart SbCl(3)/o-chloranil, were tested as Lewis acid catalysts for C-O bond metathesis and polycarbonate depolymerization. These results identified SbX(3)/o-chloranil pairs (X = Cl, Br) as simple main-group platforms for C-O bond cleavage chemistry.