A new synthetic platform accessing stereoregular polar polyolefins is introduced. We showcase the stability of aromatic azaborine derivatives by demonstrating the syndioselective polymerization of BN 2-vinylnaphthalene (BN2VN) by a monocyclopentadienyl titanium complex. Homogeneous early transition metal catalysts are well-established systems for the synthesis of highly stereoregular syndiotactic polystyrene (sPS), but the oxophilic nature of these complexes results in catalyst decomposition with polar monomers. BN2VN's compatibility with coordination polymerization, and its ability to intercept the mechanism of styrene polymerization, is attributed to its aromaticity. Stereoretentive postpolymerization oxidation of the organoborane side chain generates syndiotactic poly(vinyl alcohol) (sPVA), an example of PBN2VN's potential for diverse postfunctionalization.

Vinyl alcohol–methacrylatecopolymers have intriguing functionally rich structures but are synthetically inaccessible from vinyl acetate, the traditional precursor to polyvinyl alcohol. We report a solution via BN 2-vinylnaphthalene (BN2VN), an aromatic vinyl borane monomer. Conventional free radical copolymerization of BN2VN and methyl methacrylate (MMA) is facile. Conversion of BN2VN side chains to VA side chains is accomplished in organic solvents with Me3NO·2H2O and avoids MMA hydrolysis. The VA–MMA copolymer rapidly lactonizes to give an unprecedented macromolecule bearing both acyclic and cyclic ester residues. Methanolysis furnishes the statistical copolymer bearing vinyl alcohol, methyl methacrylate, and lactone residues. tert-Butyl methacrylate-BN2VN copolymers were shown to not lactonize.