title: Iridium-catalyzed enantioselective allylic substitution of unstabilized enolates derived from α,β-unsaturated ketones.
abstract: We report Ir-catalyzed, enantioselective allylic substitution reactions of unstabilized silyl enolates derived from α,β-unsaturated ketones. Asymmetric allylic substitution of a variety of allylic carbonates with silyl enolates gave allylated products in 62-94% yield with 90-98% ee and >20:1 branched-to-linear selectivity. The synthetic utility of this method was illustrated by the short synthesis of an anticancer agent, TEI-9826.
authors.affiliation: Department of Chemistry, University of California, Berkeley, CA 94720 (USA).
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.forename: John F
authors.initials: JF
authors.lastname: Hartwig
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D007495:Iridium / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D008968:Molecular Conformation; D011455:Prostaglandins A, Synthetic / Q000138:chemical synthesis / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000970:Antineoplastic Agents; D002254:Carbonates; D007659:Ketones; D011455:Prostaglandins A, Synthetic; D012821:Silanes; C469647:TEI9826; D007495:Iridium
keywords: asymmetric allylic substitution; asymmetric catalysis; unstabilized enolates; α,β-unsaturated ketones