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Self‐Recognition Based on Atropoisomerism with New Chiral Bidentate Ligands and Copper( I )
Author(s) -
Vincent JeanMarc,
Philouze Christian,
Pianet Isabelle,
Verlhac JeanBaptiste
Publication year - 2000
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20001002)6:19<3595::aid-chem3595>3.0.co;2-w
Subject(s) - diastereomer , chemistry , denticity , steric effects , ligand (biochemistry) , chirality (physics) , pyridine , copper , benzimidazole , stereochemistry , crystallography , nuclear magnetic resonance spectroscopy , crystal structure , medicinal chemistry , organic chemistry , receptor , biochemistry , nambu–jona lasinio model , chiral symmetry breaking , physics , quantum mechanics , quark
A new family of atropoisomeric bidentate ligands that have a dissymmetric benzimidazole‐pyridine binding site has been synthesized. Aromatic rings, that is, naphthyl, tolyl, and cumyl, were introduced in order to fine tune the complexation properties of the ligands. The tetrahedral copper( I ) complexes L 2 Cu were prepared and the structure of the complex with the naphthyl‐substituted ligand was established by X‐ray diffraction. The behavior of the L 2 Cu complexes in solution was studied by 1 H NMR spectroscopy. With the most crowded cumyl‐derived ligand, ligand self‐recognition based on chirality occured: 95 % of the complex was present in solution as a racemate RR Δ/ SS Λ, the heterochiral RS Δ/ SR Λ isomers represented only 5 % of the mixture, and the RR Λ/ SS Δ isomers were not detected. Owing to lower steric repulsions within the other L 2 Cu complexes (i.e., with the naphthyl‐ and tolyl‐based ligands) the homorecognition is less pronounced, as diastereomeric excesses of 6 and 26 % were measured, respectively.