Study on macrocyclization on acetylene-based benzoxazine dimer

Abstract

Up to the present, our group has succeeded in showing a unique benzoxazine chemistry of which the ring opening reaction terminates when the dimer is formed. Acetylene-based benzoxazine dimers, which a reactive alkyne exists at the aza group, are unique compound since their macrocycles can lead to polymers containing benzoxazine macrocycles. In this work, the macrocyclizations between acetylene-based benzoxazine dimers with diacidchlorides under heterogeneous. homogeneous and interfacial polycondensation are focused. In case of heterogeneous reaction, benzoxazine dimer with terephthaloyl dichloride provides only [2+1] linear oligoester whereas the homogeneous reaction and interfacial polycondensation give [2+2) macrocycle and [2+1] linear oligoester. By changing diacidchloride to aliphatic one, adipoyl dichloride, [1+1] macrocycle and [2+1] linear oligoester are obtained. Although theoretically, various compounds can be obtained from the macrocyclization, the present work demonstrates a simple and selective reaction to result only two types of the compounds, i.e. [2+1] linear oligoester and [1+1] or [2+2] macrocycles.