Azaborine benzylic ion stability and reactivity in ionic polymerization

Abstract

Benzylic cations and anions are implicated in the mechanism of critical organic transformations, such as styrene polymerization. We investigate the influence of BN for CC bond substitution on the reactivity...

Ring-Opening Metathesis Polymerization of the Dewar Isomer of 1,2-Azaborinine, a B–N Isostere of Benzene

“…In conclusion, we have successfully synthesized the first example of a Dewar-azaborinine polymer ( 2 ) by ROMP of Dewar isomer 1 with Grubbs and Hoveya–Grubbs second generation catalysts, as well as a Z -selective catalyst. While several azaborinine-derived polymers have recently been reported as analogues of common carbon-based polymers such as polyphenylene, polystyrene, and polyvinyl naphthalene, ,, the structure of polymers 2 and 2-Z containing 4-membered B–N heterocycles is unprecedented. Successful formation of 2 was verified by GPC, 2D NMR, and FT-IR, and the differences in the stereochemistry for the Z -selective catalyst were further evaluated by 2D NOESY and Raman measurements.…”