ABSTRACT
A one-pot synthesis of chiral [4 + 6] tetrahedral cage compounds containing a salen fragment on each face is presented. The formation of the [4 + 6] products remains in contrast to the reaction of 1,3,5-triformylphloroglucinol with chiral diamines where [2 + 3] keto-enamine pseudocyclophanes are formed exclusively. The presence of OH groups determines the structural and spectroscopic properties of these cage compounds while a change in the reaction conditions facilitates the isolation of the microcrystalline products of the specific surface area varying from 5 to 578 m(2) g(-1).
ABSTRACT
Triangular 30- and 27-membered hexaiminomacrocycles 4 and 5 of D(3) and C(3) symmetry, respectively, are readily obtained by unprecedented [3 + 3] cyclocondensation of (R,R)-1, 2-diaminocyclohexane with, accordingly, terephthalaldehyde and isophthalaldehyde. The course of the reaction, leading to macrocyclization, is governed by conformational constraints imposed on the structural components of the intermediate products, as shown by molecular modeling. X-ray analysis of cocrystal 4.AcOEt revealed that the macrocycle symmetry significantly departs from ideal D(3) symmetry due to crystal environment. Cyclic hexaamines 6 and 7 were prepared by sodium borohydride reduction of 4 and 5, respectively.
