Cyclopolymerization. XIX. Effect of N‐substituents on cyclopolymerizability of N‐allylmethacrylamides

Abstract

The effect of bulky N‐substitutents of N‐t‐butyl‐ and N‐phenyl‐N‐allylmethacrylamides (BAMA and PAMA, respectively) on their cyclopolymerizability was investigated. BAMA yielded an almost completely cyclized polymer while the degree of cyclization of poly (PAMA) was about 95%. The latter value indicates that the effect of phenyl group is comparable with that of methyl group, since N‐methyl‐N‐allylmethacrylamide was reported to give a polymer with a degree of cyclization of 93%. Structural investigation on telomerization products of BAMA and PAMA permitted the assignment of the repeating cyclic units of these polymers to that of a five‐membered ring. This structural characteristic was also supported by the observation of five‐membered cyclized radicals on ESR measurements of these monomers. Rotation around amide CN bonds of these monomers and related compounds studied by 13C‐NMR was found to be strongly dependent on N‐substitutents. The mechanism of the cyclization was discussed in terms of the structure of the ring formed and rotation around amide CN bonds of these monomers. The reactivity of the methacryloyl and allyl groups involved in these monomers were compared based on the information obtained by structural investigation of polymers and telomerization products and by ESR studies. © 1993 John Wiley & Sons, Inc.

Cyclopolymerization, 30. Design of an Unconjugated Diene with High Polymerizability Using Functional Groups with No Homopolymerization Tendency, and Synthesis of Completely Cyclized Polymers therefrom: Radical Polymerizations of N-Phenyl-N-2-(methoxycarbonyl)allyl(meth)acrylamide

“…This assignment is supported by the observation of C2O double bonds at 1 690 cm -1 for poly(5 a) which has five-membered rings as repeat cyclic units. [11] 13 C NMR studies afford additional evidence for this structural analysis. Figure 3 compares the 13 C NMR spec- Table 2), (B) 1 a, (C) poly(5 a) (no.…”

“…Comparison of the spectrum of poly(1 a) with that of poly(5 a) along with the spectrum obtained by the DEPT measurement allows the peak analysis given in Figure 3A except for the peaks denoted by numbers with a prime. During the structural studies on the polymers derived from N-phenyl-N-methallyl-2-(methoxycarbonyl)allylamine (10) (Scheme 4), we have shown that 13 C chemical shifts of phenyl carbons change extensively depending on whether a benzene ring is attached to a piperidine ring (11) or a pyrrolidine ring (12). [17] It showed that the bulkier six-membered ring does not allow the coplanar conformation between piperidine and benzene rings.…”

“…[5,6,9,10] This suggests that 1 a has a high polymerizability in addition to the high cyclization tendency. The results obtained were compared with those reported for N-substituted N-allyl-2-(methoxycarbonyl)allylamines (4) [5,6] and N-substituted N-allylmethacrylamides (5) [3,11] (Scheme 2). This is because 4 and 5 are the compounds that were synthesized and polymerized to prove the latter and former proposals, respectively.…”

Cyclopolymerization XXIII. Design of Unconjugated Dienes with High Polymerizability Using Functional Groups with No Homopolymerization Tendency and Synthesis of Completely Cyclized Polymers Therefrom: Radical Polymerizations of N-Substituted N-Allyl-2-(methoxycarbonyl)allylamines

“…Reported results of Nmethylacrylamide (MAA) 21 and N-substituted methacrylamides (RAMA) such as N-methyl-, 2 N-tert-butyl-, 22 and N-phenylmethacrylamides 22 (MAMA, BAMA, and PhAMA, respectively) are also given in Table II for comparison. SAMC yielded high polymers, while no detectable polymer could be obtained from SPMC, even after prolonged polymerization time.…”

Asymmetric Radical Cyclopolymerization of N-Allyl-N-phenylmethacrylamide in the Presence of SnCl4 and l-Menthol

“…[13][14][15] Such cyclopolymerizations are also expected to produce asymmetric centers in the resulting polymers. Cyclopolymerization of 1,5-pentadiene with an optically active metallocene catalyst was found to yield optically active polymer.…”