Refinement of the Catalyst Backbone of Chiral Intramolecular Silicon-Sulfur Lewis Pairs: Improved Enantioselectivity in the Diels-Alder Reaction of Cyclohexa-1,3-diene and Chalcone Derivatives
作者:Polina Shaykhutdinova、Sebastian Kemper、Martin Oestreich
DOI:10.1002/ejoc.201800434
日期:2018.6.22
Step by step. A new, structurally modified silicon cation intramolecularly stabilized by a sulfur donor catalyzes challenging Diels–Alder reactions of cyclohexa‐1,3‐diene and chalcone derivatives with improved enantiomeric excesses. The endo selectivity typically observed is inverted to exo with cyclopentadiene, and no enantioinduction is obtained.
循序渐进。通过硫供体分子内稳定化的新的结构改性的硅阳离子可催化环己-1,3-二烯和查尔酮衍生物的挑战性狄尔斯-阿尔德反应,并改善了对映体过量。所述内通常观察到的选择性被转化为外切与环戊二烯,并且获得没有enantioinduction。