title: Spontaneous Generation of Chirality in Simple Diaryl Ethers.
abstract: We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems.
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Lennartson
authors.affiliation: Department Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Hedström
authors.affiliation: Department Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Håkansson
mesh_terms: D001547:Benzaldehydes / Q000737:chemistry; D001555:Benzene Derivatives / Q000737:chemistry; D002942:Circular Dichroism; D003460:Crystallization; D004987:Ethers / Q000737:chemistry*; D008968:Molecular Conformation; D010647:Phenyl Ethers / Q000737:chemistry; D013237:Stereoisomerism; D014050:Toluene / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: C000606014:1,3-dimethyl-2-phenoxybenzene; D001547:Benzaldehydes; D001555:Benzene Derivatives; D004987:Ethers; D010647:Phenyl Ethers; C000606016:di(p-tolyl)ether; C015126:di-(4-aminophenyl)ether; C064808:3-phenoxybenzaldehyde; D014050:Toluene
keywords: CD-spectroscopy; Ullmann coupling; optical resolution; spontaneous resolution; supramolecular chemistry