Switchable Stereoselectivity: The Effects of Substituents on the D2-Symmetric Biphenyl Backbone of Phosphoramidites in Copper-Catalyzed Asymmetric Conjugate Addition Reactions with Triethylaluminium
A highly enantioselective copper‐catalyzed conjugateaddition with triethylaluminium was developed using phosphoramidite ligands bearing a D2‐symmetric biphenylbackbone. For these ligands we demonstrated that the 3,3′,5,5′‐substituents on the biphenylbackbone can completely reverse the absolute configuration of the products.
Copper-Catalyzed Regio- and Enantioselective Synthesis of Chiral Enol Acetates and β-Substituted Aldehydes
作者:Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1021/ja105585y
日期:2010.9.29
The in situ transformation of α,β-unsaturated aldehydes into α-chloroallylic acetates and subsequent copper-catalyzed regio- and enantioselective (up to 94% ee) allylic alkylation with Grignard reagents provides chiral enol acetates and chiral β-substituted aldehydes in a one-pot protocol.