Catalytic Asymmetric Claisen Rearrangement of Enolphosphonates: Construction of Vicinal Tertiary and All-Carbon Quaternary Centers
作者:Jiajing Tan、Cheol-Hong Cheon、Hisashi Yamamoto
DOI:10.1002/anie.201203092
日期:2012.8.13
A copper‐catalyzed enantioselective Claisenrearrangement of easily accessible enolphosphonates using the commercially available PhBOX as the chiral ligand was developed. A wide range of rearrangement products with contiguous tertiary and all‐carbon quaternarycenters were obtained in excellent yields and stereoselectivities. The α‐ketophosphonate substituent in the products could be easily transformed
Planar-Chiral Cyclopentadienyl-Ruthenium-Catalyzed Regio- and Enantioselective Asymmetric Allylic Alkylation of Silyl Enolates under Unusually Mild Conditions
report the asymmetric allylic alkylation of allylic chlorides with silyl enolates as a carbon nucleophile using a planar‐chiral cyclopentadienyl‐ruthenium (Cp′Ru) catalyst. The reaction proceeds under unusually mild conditions to give the desired branched products with complete regioselectivity and high enantioselectivity, and reactive functional groups, such as aldehyde, can be tolerated. In this reaction