title: Synthesis, π-face-selective aggregation, and π-face chiral recognition of configurationally stable C(3)-symmetric propeller-chiral molecules with a π-core.
abstract: The C3 -symmetric propeller-chiral compounds (P,P,P)-1 and (M,M,M)-1 with planar π-cores perpendicular to the C3 -axis were synthesized in optically pure states. (P,P,P)-1 possesses two distinguishable propeller-chiral π-faces with rims of different heights named the (P/L)-face and (P/H)-face. Each face is configurationally stable because of the rigid structure of the helicenes contained in the π-core. (P,P,P)-1 formed dimeric aggregates in organic solutions as indicated by the results of (1) H NMR, CD, and UV/Vis spectroscopy and vapor pressure osmometry analyses. The (P/L)/(P/L) interactions were observed in the solid state by single-crystal X-ray analysis, and they were also predominant over the (P/H)/(P/H) and (P/L)/(P/H) interactions in solution, as indicated by the results of (1) H and 2D NMR spectroscopy analyses. The dimerization constant was obtained for a racemic mixture, which showed that the heterochiral (P,P,P)-1/(M,M,M)-1 interactions were much weaker than the homochiral (P,P,P)-1/(P,P,P)-1 interactions. The results indicated that the propeller-chiral (P/L)-face interacts with the (P/L)-face more strongly than with the (P/H)-face, (M/L)-face, and (M/H)-face. The study showed the π-face-selective aggregation and π-face chiral recognition of the configurationally stable propeller-chiral molecules.
authors.affiliation: Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Sendai 980-8578 (Japan), Fax: (+81) 22-795-6811; Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aoba, Sendai 980-8578 (Japan).
authors.forename: Nozomi
authors.initials: N
authors.lastname: Saito
authors.forename: Ryo
authors.initials: R
authors.lastname: Terakawa
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yamaguchi
mesh_terms: D018360:Crystallography, X-Ray; D019281:Dimerization; D046911:Macromolecular Substances / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010616:Phenanthrenes / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D046911:Macromolecular Substances; D010616:Phenanthrenes; D011083:Polycyclic Compounds; C031660:helicenes
keywords: aggregation; annulenes; helicene; recognition; selectivity