Rh-catalyzed formation of dioxolanes from alpha-alkyl diazoesters: diastereoselective cycloadditions of carbonyl ylides with selectivity over beta-hydride elimination.
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.
DeAngelis
Andrew
A
Brown Laboratories, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
Panne
Patricia
P
Yap
Glenn P A
GP
Fox
Joseph M
JM
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
D004148:Dioxolanes; D004952:Esters; D007659:Ketones; D012211:Rhenium; D006859:Hydrogen