title: Enantioselective iodolactonization of disubstituted olefinic acids using a bifunctional catalyst.
abstract: The enantioselective iodolactonizations of a series of diversely substituted olefinic carboxylic acids are promoted by a BINOL-derived, bifunctional catalyst. Reactions involving 5-alkyl- and 5-aryl-4(Z)-pentenoic acids and 6-alkyl- and 6-aryl-5(Z)-hexenoic acids provide the corresponding γ- and δ-lactones having stereogenic C-I bonds in excellent yields and >97:3 er. Significantly, this represents the first organocatalyst that promotes both bromo- and iodolactonization with high enantioselectivities. The potential of this catalyst to induce kinetic resolutions of racemic unsaturated acids is also demonstrated.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, United States.
authors.forename: Chao
authors.initials: C
authors.lastname: Fang
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Paull
authors.forename: J Caleb
authors.initials: JC
authors.lastname: Hethcox
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Shugrue
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Martin
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006842:Hydrocarbons, Brominated / Q000737:chemistry; D006847:Hydrocarbons, Iodinated / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; C406944:BINOL, naphthol; D002264:Carboxylic Acids; D006842:Hydrocarbons, Brominated; D006847:Hydrocarbons, Iodinated; D007783:Lactones; D009284:Naphthols