(3+3)-Cyclocondensation of the enantiopure and racemic forms of trans-1,2-diaminocyclohexane with terephthaldehyde.: Formation of diastereomeric molecular triangles and their stereoselective solid-state stacking into microporous chiral columns

The non-templated reaction of both the homochiral as well as the racemic form of trans-1,2-diaminocyclohexane with terephthaldehyde affords (3+3)-cyclocondensed molecular triangles in practically quantitative yields. The configuration of the diastereomeric products resulting in the individual reactions has been determined by H-1 and C-13 NMR spectroscopy. Unambiguous proof has been obtained by X-ray crystal structure analysis of both alternative diastereomers, revealing also a stereoselective stacking of the triangles into microporous chiral columns. (C) 2001 Elsevier Science Ltd. All rights reserved.