Iron and Ruthenium Lewis Acid Catalyzed Asymmetric 1,3-Dipolar Cycloaddition Reactions between Nitrones and Enals
作者:Florian Viton、Gérald Bernardinelli、E. Peter Kündig
DOI:10.1021/ja017814f
日期:2002.5.1
The single coordination-site transition metal Lewisacids [CpM(BIPHOP-F)][SbF6] (M = Fe, Ru) catalyze the [3+2] dipolar cycloadditionreaction between reactive nitrones and alpha,beta-unsaturated aldehydes to give chiral isoxazolidines with ee values of 75 to >96%. The stereochemistry of the major enantiomer is consistent with an endo approach of the nitrone to the Calpha-Si-face of the enal in the s-trans