A New Synthetic Method for (Aza)n[3n]cyclophanes by Diethyl Phosphoramidates

ABSTRACT (Aza) n [3 n ]cyclophanes are synthesized by the N-alkylation of diethyl phosphoramidates with bis(bromomethyl)arenes under phase-transfer conditions or anhydrous conditions in the presence of an appropriate base. The method affords N-(diethoxyphosphoryl)(aza) n [3 n ]cyclophanes in moderate yields and can be applied to the synthesis of various types of azacyclophanes. The N-phosphorylated cyclophanes are highly soluble in organic solvents and the diethoxyphosphoryl groups are readily cleaved under acidic conditions to give the corresponding secondary amines.