title: Asymmetric Ni(II)/Cr(II)-mediated coupling reaction: stoichiometric process.
abstract: [reaction: see text] Via an X-ray analysis, the sulfonamide bearing R(1) = i-Pr, R(2) = Me, and R(3) = Me is shown to be a tridentate ligand to a Cr(III) salt. This class of ligands, represented by R(1) = t-Bu, R(2) = 2-naphthyl, and R(3) = Me, is effective to achieve an asymmetric Ni/Cr-mediated coupling reaction and, with the C14-C38 segment of halichondrins, its synthetic potential has been demonstrated. A possible mechanism is suggested for the process.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: Zhao-Kui
authors.initials: ZK
authors.lastname: Wan
authors.forename: Hyeong-Wook
authors.initials: HW
authors.lastname: Choi
authors.forename: Fu-An
authors.initials: FA
authors.lastname: Kang
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Nakajima
authors.forename: Damtew
authors.initials: D
authors.lastname: Demeke
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Kishi
mesh_terms: D002384:Catalysis; D002857:Chromium / Q000737:chemistry*; D004988:Ethers, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry*; D008024:Ligands; D018942:Macrolides; D008968:Molecular Conformation; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D013237:Stereoisomerism; D000095662:Polyether Polyketides
chemical_list: D002857:Chromium; D004988:Ethers, Cyclic; D008024:Ligands; D018942:Macrolides; D009532:Nickel; C070519:halichondrin B; D000095662:Polyether Polyketides