Spontaneous Copolymerization of 1,3-Dehydroadamantanes

On mixing of 1,3-dehydroadamantane, 1, with electron-deficient vinyl monomers such as acrylonitrile and methyl acrylate in THF at r.t. in the absence of any initiator, the copolymerization spontaneously proceeded to give alternating copolymers in 28-88 % yield. By contrast, no reaction of 1 occurred, when isobutyl vinyl ether or styrene was mixed under the similar conditions. These contrastive results indicate the high electron density of a central s-bond in a strained [3.3.1]propellane derivative, 1. Alternating sequences of the resulting copolymers were characterized by NMR and MALDI-TOF-MS measurements. DSC and TGA measurements revealed the high thermal stability of the alternating copolymers containing bulky and stiff adamantane skeletons.