Enantioselective synthesis of planar-chiral 1,n-dioxa[n]paracyclophanes via catalytic asymmetric ortho-lithiation.
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.
Kanda
Kazumasa
K
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Okubo, Shinjuku, Tokyo 169-8555, Japan.
Endo
Kohei
K
Shibata
Takanori
T
D002384:Catalysis; D004988:Ethers, Cyclic / Q000737:chemistry*; D013237:Stereoisomerism
D004988:Ethers, Cyclic