| Abstract: | A novel group transfer polymerization via hetero-Diels-Alder reaction is described. When 1-trimethylsiloxybenzocyclobutene ( 1 ) was treated with a catalytic amount of p-anisaldehyde (4-methoxybenzaldehyde) and TASF (tris(dimethylamino)sulfonium difluorotrimethylsilanide) at room temperature for 0.5 h, poly1,2-phenylene-1-(trimethylsiloxy)ethylene] was obtained quantitatively. The number-average molecular weight of the polymer was M?n = 2000 and the molecular weight distribution was narrow (ratio of weight-to number-average molecular weights M?w/M?n = 1.18). Structural characteristics suggested a polymerization mechanism involving isomerization of 1 to o-quinodimethane and successive hetero-Diels-Alder reaction leading to poly1,2-phenylene-1-trimethylsiloxy ethylene]. The living-like nature of the polymerization was supported by a monomer addition experiment in which the molecular weight increased according to the increase of the added monomer. |
