Synthesis of a Troger's Base Analogue via Stereoselective Reductive Coupling of N-Phenylpiperazine to 2,5-Norbornanedione.

The reaction of N-phenylpiperazines with 2,5-norbornanedione and NaCNBH sub 3 gives the endo, endo dipiperazinyl norbornanes. The phenylpiperazine substitutents define a right triangular cavity potentially useful for host-guest studies, as determined by x-ray crystallography and solution phase dipole moment measurements. Interactions between the trialkylamine groups and acids were observed by NMR. The substituted norbornanes are analogous to Troger's base in that they are concave, basic, and chiral.