Design of Structurally Rigid <i>trans</i>-Diamine-Based Tf-Amide Organocatalysts with a Dihydroanthracene Framework for Asymmetric Conjugate Additions of Heterosubstituted Aldehydes to Vinyl Sulfones
作者:Shin A. Moteki、Senmiao Xu、Satoru Arimitsu、Keiji Maruoka
DOI:10.1021/ja107897t
日期:2010.12.8
Asymmetric conjugateaddition of α-heterosubstituted aldehydes such as α-amido and α-alkoxy aldehydes to vinylsulfone was effected under the influence of structurally rigid trans-diamine-based Tf-amido organocatalyst (S,S)-2 with a dihydroanthracene framework to furnish α,α-dialkyl(amido)aldehydes and α,α-dialkyl(alkoxy)aldehydes with high enantioselectivity. The chiral efficiency of the structurally
Asymmetric synthesis of cyclopropyl phosphonates using chiral terpenyl sulfonium and selenonium ylides
作者:Wanda H. Midura、Jacek Ścianowski、Anna Banach、Adrian Zając
DOI:10.1016/j.tetasy.2014.10.002
日期:2014.11
The asymmetriccyclopropanation of a vinylphosphonate using optically active sulfonium and selenonium ylides derived from (−)-menthol and (+)-limonene was developed. The ylides were generated in situ by the reaction of the corresponding sulfonium or selenonium salt in the presence of potassium carbonate or DBU as a base. The transfer of the CHPh and CHCO2Et groups into the cyclopropane ring showed