title: Catalytic Ni/Cr-mediated macrocyclization without use of high-dilution techniques.
abstract: The feasibility of catalytic Ni/Cr-mediated macrocyclization was demonstrated for the two substrates chosen from the halichondrin area. With 5 mol % of Ni and Cr catalysts, the macrocyclization was realized without use of high-dilution techniques. The reported method has a number of appealing features, including user-friendliness, easy workup, apparent scalability, and cost-effectiveness. In addition, all the required reagents are commercially available or obtainable in one or two steps from commercially available chemicals.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Namba
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Kishi
mesh_terms: D002384:Catalysis; D002857:Chromium / Q000737:chemistry*; D003500:Cyclization; D004988:Ethers, Cyclic / Q000138:chemical synthesis*; D018942:Macrolides; D008722:Methods; D009532:Nickel / Q000737:chemistry*; D000095662:Polyether Polyketides
chemical_list: D002857:Chromium; D004988:Ethers, Cyclic; D018942:Macrolides; D009532:Nickel; C070519:halichondrin B; D000095662:Polyether Polyketides