title: Enantioselective aldol reactions catalyzed by chiral phosphine oxides.
abstract: The development of enantioselective aldol reactions catalyzed by chiral phosphine oxides is described. The aldol reactions presented herein do not require the prior preparation of the masked enol ethers from carbonyl compounds as aldol donors. The reactions proceed through a trichlorosilyl enol ether intermediate, formed in situ from carbonyl compounds, which then acts as the aldol donor. Phosphine oxides activate the trichlorosilyl enol ethers to afford the aldol adducts with high stereoselectivities. This procedure was used to realize a directed cross-aldol reaction between ketones and two types of double aldol reactions (a reaction at one/two α position(s) of a carbonyl group) with high diastereo- and enantioselectivities.
authors.affiliation: Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto 862-0973, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kotani
authors.forename: Masaharu
authors.initials: M
authors.lastname: Sugiura
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakajima
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D010087:Oxides / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000438:Alcohols; D000447:Aldehydes; D007659:Ketones; D010087:Oxides; D010720:Phosphines
keywords: aldol reaction; diastereoselectivity; enantioselectivity; organocatalysis; phosphine oxides