title: Enantioselective synthesis of planar-chiral 1,n-dioxa[n]paracyclophanes via catalytic asymmetric ortho-lithiation.
abstract: Highly enantioselective ortho-lithiation and dilithiation of 1,n-dioxa[n]paracyclophanes were realized with the use of sec-butyllithium and a catalytic or stoichiometric amount of sparteine. Quenching with various electrophiles, such as iodine, iodomethane, and chlorodiphenylphosphine, afforded chiral mono- and disubstituted paracyclophanes with good to excellent ee.
authors.affiliation: Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Okubo, Shinjuku, Tokyo 169-8555, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Kanda
authors.forename: Kohei
authors.initials: K
authors.lastname: Endo
authors.forename: Takanori
authors.initials: T
authors.lastname: Shibata
mesh_terms: D002384:Catalysis; D004988:Ethers, Cyclic / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D004988:Ethers, Cyclic