Synthesis of an ortho-triazacyclophane: N,N',N''-trimethyltribenzo-1,4,7-triazacyclononatriene.

N,N',N''-trimethyltribenzo-1,4,7-triazacyclononatriene has been synthesized via sequential palladium-catalyzed Buchwald-Hartwig N-arylation reactions affording the 9-membered triaza o-cyclophane in 35% overall yield. An X-ray crystal structure shows the new cyclophane to have a C2-symmetric saddle conformation, as compared to the crown conformation exhibited by the related carbocyclic cyclotriveratrylene (CTV).