New Approach to Cyclophanes Containing Ethyleneoxy Bridge by Glaser–Eglinton Coupling
摘要:
Three strategies have been explored to generate cyclophane derivatives. In this regard, we identified alkyne metathesis, Diels-Alder reaction, and Glaser-Eglinton coupling as key steps. To this end, cyclophane derivatives containing ethyleneoxy bridge were successfully synthesized in four steps involving Glaser-Eglinton coupling and catalytic hydrogenation sequence.
The 17-crown-5 unit, C26H26Br2O5, consisting of a 1,2-bis(bromomethyl) group, three benzo groups and diethylene glycol, was prepared from the reaction of 1,2,4,5-tetrakis(bromomethyl)benzene and bis-phenol in the presence of sodium hydride as a base. This molecule seems to offer an internal cavity for the formation of a host-guest complex.