N-alkyl salts derived from ephedrine do not promote enantioselective Corey-Chaykovsky reactions involving sulfonium methylides under phase-transfer conditions

作者：Kavanagh Sarah A; Connon Stephen J^*

来源：Tetrahedron: Asymmetry , 2008, 19(12): 1414-1417.

DOI：10.1016/j.tetasy.2008.05.029

N-Alkyl salts derived from ephedrine have twice been reported to act as chiral phase-transfer catalysts in Corey-Chaykovsky reactions between sulfonium ylides and benzaldehyde; reportedly furnishing the terminal epoxide product in moderate-excel lent enantiomeric excess. This study unequivocally demonstrates that these reactions proceed without measurable stereoinduction and explains how previous studies mistakenly attributed product optical activity to asymmetric catalysis.

• 出版日期2008-6-30