Efficient Syntheses and Resolutions of Inherently Chiral Calix[4]quinolines in the Cone and Partial-Cone Conformation
- 17 August 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Organic Chemistry
- Vol. 70 (19), 7662-7671
- https://doi.org/10.1021/jo050980b
Abstract
The syntheses of five pairs of novel inherently chiral calix[4]arenes are described. Two synthetic routes were adopted to generate racemic 3-carboxylic or 2-carboxylic group substituted calix[4]quinolines in the cone or the partial-cone conformation, respectively. The chiral products were thoroughly characterized by various spectroscopic methods. The optical resolutions of chiral calix[4]quinolines 5, 6, 11, and 17 were successfully achieved through the separation of their diastereomers using common column chromatography or preparative TLC. The chirality of compound 20 was proven by the splitting of the 1H NMR signals in the presence of Pirkle's reagent. The 1H NMR features of the diastereomers are discussed. The CD spectra of each pair of enantiomers showed excellent mirror images. The experimental results disclose that 3-carboxylic calix[4]quinolines can be resolved more easily than the 2-carboxylic ones in both the cone conformation and the partial-cone conformation.Keywords
This publication has 16 references indexed in Scilit:
- Preparation of enantiopure inherently chiral calix[5]arenesTetrahedron: Asymmetry, 2005
- Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff BasesMolecules, 2001
- Resolution of inherently chiral calix[4]arenes with AABB and CDCD substitution patterns on the upper and lower rims, respectivelyTetrahedron: Asymmetry, 2000
- Acid-Promoted Rearrangement of Carbonate Functionality Anchored to the Lower Rim of a Calix[4]arene Skeleton: A New Class of Chiral Calix[4]arene and Its Chiroptical PropertiesOrganic Letters, 2000
- Synthesis, Optical Resolution and Complexation Properties of Inherently Chiral Monoalkylated p-tert-Butyl-(1,2)-calix[4]crown EthersThe Journal of Organic Chemistry, 1997
- Resolution of inherently chiral 1,4-2,5-calix[8]bis-crown-4 derivatives by enantioselective HPLCTetrahedron: Asymmetry, 1997
- Definitive Evidence for Inhibition of Calix[6]arene Ring Inversion Obtained from a 1,3-Xylenyl-Bridged Chiral Calix[6]areneJournal of the American Chemical Society, 1996
- Synthetic strategies to inherently chiral calix[4]arenes with mixed ligating functionalities at the lower rimThe Journal of Organic Chemistry, 1994
- A ‘One-Pot’ Synthesis of Substituted 3-Carboethoxy-2-Methylquinolines from Ethyl AcetoacetateSynthetic Communications, 1987
- Synthesis of new cyclopenta-fused polycyclic aromatic hydrocarbon isomers of cata-annelated benzenoid systemsThe Journal of Organic Chemistry, 1987