title: Catalytic asymmetric epoxidation of alpha,beta-unsaturated amides: efficient synthesis of beta-aryl alpha-hydroxy amides using a one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process.
abstract: The catalytic asymmetric epoxidation of alpha,beta-unsaturated amides using Sm-BINOL-Ph3As=O complex was succeeded. Using 5-10 mol % of the asymmetric catalyst, a variety of amides were epoxidized efficiently, yielding the corresponding alpha,beta-epoxy amides in up to 99% yield and in more than 99% ee. Moreover, the novel one-pot tandem process, one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process, was developed. This method was successfully utilized for the efficient synthesis of beta-aryl alpha-hydroxy amides, including beta-aryllactyl-leucine methyl esters. Interestingly, it was found that beneficial modifications on the Pd catalyst were achieved by the constituents of the first epoxidation, producing a more suitable catalyst for the Pd-catalyzed epoxide opening reaction in terms of chemoselectivity.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Nemoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kakei
authors.forename: Vijay
authors.initials: V
authors.lastname: Gnanadesikan
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Tosaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohshima
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Shibasaki
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis*; D000475:Alkenes / Q000737:chemistry*; D000577:Amides / Q000138:chemical synthesis*; D002384:Catalysis; D004852:Epoxy Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000438:Alcohols; D000475:Alkenes; D000577:Amides; D004852:Epoxy Compounds; D010165:Palladium