title: Asymmetric allylation of α-ketoester-derived N-benzoylhydrazones promoted by chiral sulfoxides/N-oxides Lewis bases: highly enantioselective synthesis of quaternary α-substituted α-allyl-α-amino acids.
abstract: Chiral sulfoxides/N-oxides (R)-1 and (R,R)-2 are effective chiral promoters in the enantioselective allylation of α-keto ester N-benzoylhydrazone derivatives 3a-g to generate the corresponding N-benzoylhydrazine derivatives 4a-g, with enantiomeric excesses as high as 98%. Representative hydrazine derivatives 4a-b were subsequently treated with SmI2, and the resulting amino esters 5a-b with LiOH to obtain quaternary α-substituted α-allyl α-amino acids 6a-b, whose absolute configuration was assigned as (S), with fundament on chemical correlation and electronic circular dichroism (ECD) data.
authors.affiliation: Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, D.F., México.
authors.forename: Gloria
authors.initials: G
authors.lastname: Reyes-Rangel
authors.forename: Yamir
authors.initials: Y
authors.lastname: Bandala
authors.forename: Fred
authors.initials: F
authors.lastname: García-Flores
authors.forename: Eusebio
authors.initials: E
authors.lastname: Juaristi
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000498:Allyl Compounds / Q000737:chemistry; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D002942:Circular Dichroism; D004952:Esters / Q000737:chemistry; D006835:Hydrazones / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D058115:Lewis Bases / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D013454:Sulfoxides / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D000498:Allyl Compounds; D000596:Amino Acids; D004952:Esters; D006835:Hydrazones; D007659:Ketones; D058115:Lewis Bases; D013454:Sulfoxides
keywords: Asymmetric allylation; Lewis bases; chiral sulfoxides; quaternary carbons; α-allyl-α-amino acids