Asymmetric cyclopolymerization ofN-tert-butyl-N-allylacrylamide in the presence of ?-cyclodextrin

Abstract

The radical polymerization of N‐tert‐butyl‐N‐allylacrylamide (t‐BAA) was carried out in a dimethyl sulfoxide/H2O mixture in the presence of β‐cyclodextrin (β‐CD). The polymerization proceeded with the complete cyclization of the t‐BAA unit and yielded optically active poly(t‐BAA). The IR spectrum of the obtained polymer showed that the cyclic structure in the polymer was a five‐membered ring. The optical activity of poly(t‐BAA) increased with an increasing molar ratio of β‐CD to the t‐BAA monomer. The interaction of β‐CD with t‐BAA was confirmed by 1H NMR and 13C NMR analyses of the polymerization system. It is suggested that interaction of the t‐BAA monomer with the hydrophobic cavity of β‐CD plays an important role in the asymmetric cyclopolymerization of t‐BAA. The radical copolymerization of t‐BAA with styrene (St), methyl methacrylate, ethyl methacrylate, or benzyl methacrylate (BMA) also produced optically active copolymers with a cyclic structure from the t‐BAA unit. St and BMA carrying a phenyl group were predicted to compete with t‐BAA for interaction with β‐CD in the copolymerization system. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2098–2105, 2000

Highly reactive, liquid diacrylamides via synergistic combination of spatially arranged curing moieties

“…Compound 6 showed only two peaks before and after polymerization, while the spectrum of 2 contains the typical acetamide peak at 1633 cm −1 before and after polymerization. In accordance with the FTIR data and literature [ 27 – 28 ], we propose that some of the possible intramolecular reaction products (intermolecular cyclization products are conceivable as well) start most likely from the formed acrylamide radical as depicted in Scheme 6 . Upon subsequent cyclization, either 6-membered δ-lactams, or 5-membered γ-lactams can be formed.…”

“…As stated earlier [ 24 ] we strive to investigate the unique physical properties and reactivity of tertiary N , N ’-diallyl-diacrylamides. Closely related to this class of crosslinkers are bifunctional N -alkyl- N -allylacrylamides, which are known to undergo radical cyclopolymerization due to their adjacent double-bond functionalities [ 25 – 27 ]. The propagation reaction of these structures proceeds intramolecularly between acryl and allyl groups and intermolecularly (mostly) between polymer-radical and acrylamide groups.…”

Rhodium/Chiral Diene-Catalyzed Asymmetric Cyclopolymerization of Achiral 1,8-Diynes

“…Although this type of cyclopolymerization of nonconjugated diynes has been studied by use of a rhodium catalyst, − helix-sense-selective asymmetric cyclopolymerization of achiral diynes has not been reported, to the best of our knowledge. − Here we report that the asymmetric cyclopolymerization is realized by use of a rhodium/chiral diene catalyst for the reaction of 1,8-diynes where the two alkynes are terminal and internal ones.…”