Cyclopolymerization, 24. Cyclopolymerizability of an unconjugated triene with functional groups with no homopolymerization tendency: Radical polymerizations of N , N ‐diallyl‐2‐(methoxy‐carbonyl)allylamine

N , N ‐Diallyl‐2‐(methoxycarbonyl)allylamine ( 1a ), a trifunctional compound with functional groups of low homopolymerizability, was synthesized and its radical cyclopolymerizability was investigated. Monomer 1a was polymerized to yield high molecular weight polymers with a considerably high polymerization rate; the degree of cyclization (DC) of poly( 1a ) was about 55%, irrespective of the polymerization conditions, while bifunctional compounds with functional groups of low homopolymerizability have been known to yield highly cyclized polymers. Pendant unsaturations detected in poly( 1a ) were found to consist almost exclusively of allyl groups. The acryloyl groups and one of the allyl groups of 1a can be regarded as one functional group in a pair with high polymerizability, since N ‐allyl‐ N ‐propyl‐2‐(methoxycarbonyl)allylamine which has the structure of 1a with one of its allyl groups saturated has been known to yield linear polymers with a DC of 100%. This consideration indicates that 1a has similar cyclopolymerizability to unsymmetrical bifunctional monomers the functional groups of which have high and low homopolymerizability. This is the reason why 1a has low cyclopolymerizability, since such unsymmetrical bifunctional monomers have generally low cyclopolymerizability. The high polymerization tendency of 1a is attributed to the high conjugative nature of the acryloyl group as proven by 13 C NMR.