title: Stereoselectivity in nucleophilic additions to 3-azidoalkanals.
abstract: The stereoselectivity of nucleophilic additions to 3-azidoalkanals was investigated. Non-chelating, BF(3)·OEt(2)-mediated Sakurai addition to 3-azidoalkanals afforded 1,3-anti products, whereas use of a chelating Lewis acid, TiCl(4), resulted in 1,3-syn products with moderate selectivity. A boat-like chelation structure of the 3-azidoalkanal with the Lewis acid is proposed to be consistent with the 1,3-syn selectivity of the reactions. Mukaiyama aldol addition to 3-azidohexanal generated 1,3-anti products regardless of the chelating ability of the Lewis acid.
authors.affiliation: The University of Kansas Chemical Methodologies and Library Development Center, 2034 Becker Dr., Delbert M. Shankel Structural Biology Center, Lawrence, Kansas 66047, USA.
authors.forename: Chan Woo
authors.initials: CW
authors.lastname: Huh
authors.forename: Chad
authors.initials: C
authors.lastname: Schroeder
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Singh
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Aubé
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D001386:Azides / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D000447:Aldehydes; D001386:Azides