title: Substrate-controlled Michael additions of chiral ketones to enones.
abstract: Substrate-controlled Michael additions of the titanium(IV) enolate of lactate-derived ketone 1 to acyclic α,β-unsaturated ketones in the presence of a Lewis acid (TiCl4 or SnCl4) provide the corresponding 2,4-anti-4,5-anti dicarbonyl compounds in good yields and excellent diastereomeric ratios. Likely, the nucleophilic species involved in such additions are bimetallic enolates that may add to enones through cyclic transition states. Finally, further studies indicate that a structurally related β-benzyloxy chiral ketone can also participate in such stereocontrolled conjugate additions.
authors.affiliation: †Departament de Química Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Fàbregas
authors.affiliation: †Departament de Química Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Gómez-Palomino
authors.affiliation: †Departament de Química Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain.
authors.forename: Miquel
authors.initials: M
authors.lastname: Pellicena
authors.affiliation: †Departament de Química Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Reina
authors.affiliation: †Departament de Química Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Romea
authors.affiliation: †Departament de Química Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain.
authors.forename: Fèlix
authors.initials: F
authors.lastname: Urpí
authors.affiliation: ‡Unitat de Difracció de RX. CCiTUB, Universitat de Barcelona, Carrer Solé i Sabarís 1-3, 08028 Barcelona, Catalonia, Spain.
authors.forename: Mercè
authors.initials: M
authors.lastname: Font-Bardia
mesh_terms: D002384:Catalysis; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D058116:Lewis Acids / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism; D014025:Titanium / Q000737:chemistry
chemical_list: D007659:Ketones; D058116:Lewis Acids; D019344:Lactic Acid; C025096:titanium tetrachloride; D014025:Titanium