Molecular structure and conformation of the (Z) and (E) geometric isomers of 2-(2-phenylbenzylidene)-3 quinuclidinone
The crystal structures of the (Z) and (E) geometric isomers of 2-(2-phenylbenzylidene)-3-quinuclidinone were solved by direct methods, using diffractometric data, and refined to final R values of 0.040 and 0.061. The molecules of the (Z) and (E) geometric isomers show trans and cis conformation of the substituents around the double bond, respectively. The quinuclidine and the diphenyl moieties show deformations in their geometric and conformational parameters due to the need of releasing intramolecular strains and/or non-bonded interactions.
Santini, Antonello,Benedetti, Ettore,Pedone, Carlo,Giordano, Marialuisa,Caliendo, Giuseppe,Santagada, Vincenzo,Grieco, Paolo,Greco, Giovanni
Synthesis and neurokinin antagonist activity of 2-benzylidene- and 2- benzyl-3-benzylamino quinuclidines
Molecular modeling studies based on the potent NK-1 antagonist CP-96,345 led us to the identification of some 2-benzylidene- and 2-benzyl-3- benzylaminoquinuclidine derivatives as potential antagonists at the NK receptor subtypes. The synthesized compounds, whose Z/E isomerism has been defined by X-ray analysis, show only moderate potency on the three neurokinin receptors. The possible reasons of the low potency exhibited by the tested compounds are discussed.