Enantioselective Inclusion Complexation ofN-Nitrosopiperidines by Steroidal Bile Acids

Abstract

N-nitrosamines, whose chirality is solely due to hindered rotation about the N-N bond, are enantioselectively enclathrated by the crystal host matrices of cholic or deoxycholic acid, as evidenced by X-ray crystallography (see structure in picture) and CD spectra.

Supramolecular Chirality in Crystalline Assemblies of Bile Acids and Their Derivatives; Three-Axial, Tilt, Helical, and Bundle Chirality

“…Dehydrocholic acid (Vi) is known to be an effective host for the enantioresolution of sulfoxides and cyclic amides [118][119][120][121]. It is noteworthy that Ia includes chiral conformers of achiral compounds [122][123][124].…”

Bile Acids as Building Blocks of Supramolecular Hosts

“…have also investigated bile acid-based inclusion complexes and found optical activity in formally achiral guest molecules, aromatic ketones, included in the crystal lattice of bile acids [ 128 ]. They have also reported on enantioselective inclusion complexation of N -nitrosopiperidines by bile acids [ 129 ].…”

Conformational transformation coupled with the order–disorder phase transition in 2-methyl-1,3-cyclohexanedione crystals

“…Although molecular crystals are sometimes described as oriented gases (Rohleder, 1989), the intermolecular interactions and the couplings of lattice-mode and molecular vibrations cannot be neglected. While largeamplitude vibrations or puckering disorder could not be activated without conformational¯exibility in molecules, the interactions with the lattice may stabilize different conformations or exited states of molecules embedded in the crystalline environment (Gdaniec et al, 1999). The mechanisms of coupling between the lattice and molecular modes of vibrations, as well as the role of intermolecular interactions for the crystal and molecular transformations, differ considerably for different substances and are still not fully understood.…”