| Abstract
| - The cyclization reactions of N-methyl-N,N-diallylamine (1), N-methyl-N-allyl-2-(methoxycarbonyl)allylamine(2), and N-methyl-N-methallyl-2-(methoxycarbonyl)allylamine (3) have been modeled in their cyclopolymerization mechanism. The experimentally observed regioselectivity has been reproduced and explained interms of steric and electronic factors. The activation energies for the cyclization of the model compoundsrepresenting 1, 2, and 3 are 5.41, 8.68, and 11.59 kcal/mol, respectively. The ester substituent on 2 and 3 isfound to increase the activation energy of the exo transition structure by its steric effect without making asignificant effect in the barrier height of endo. The destabilization on the exo transition structure is enhancedby methyl substitution on the double bond. The experimentally determined stereoselectivity for 1 and 2 havealso been reproduced. The lower activation energy for 1 despite its low polymerizability is justified byconsidering the dominance of competing reactions, like H-abstraction and homopolymerization.
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