title: Rh-catalyzed formation of dioxolanes from alpha-alkyl diazoesters: diastereoselective cycloadditions of carbonyl ylides with selectivity over beta-hydride elimination.
abstract: Described here is a diastereoselective Rh-catalyzed method for the preparation of dioxolanes from alpha-alkyl-alpha-diazoesters. This represents the first general method for generating carbonyl ylides from alpha-diazoesters that possess beta-hydrogens, as such diazo compounds typically give rise to alkenes via beta-hydride elimination. Subsequent cycloaddition with aromatic aldehydes gives tetrasubstituted dioxolanes with unusually high diastereoselectivity. A model is set forth to explain the diastereoselectivity of the cycloaddition.
authors.affiliation: Brown Laboratories, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: DeAngelis
authors.forename: Patricia
authors.initials: P
authors.lastname: Panne
authors.forename: Glenn P A
authors.initials: GP
authors.lastname: Yap
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Fox
mesh_terms: D002384:Catalysis; D003500:Cyclization; D004148:Dioxolanes / Q000737:chemistry*; D004952:Esters; D006859:Hydrogen / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D012211:Rhenium / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared
chemical_list: D004148:Dioxolanes; D004952:Esters; D007659:Ketones; D012211:Rhenium; D006859:Hydrogen