Asymmetric meso-Epoxide Ring-Opening with Trimethylsilyl Cyanide Promoted by Chiral Binuclear Complexes of Titanium. Dichotomy of CC versus CN Bond Formation
作者:Yuriâ N. Belokon、Denis Chusov、Alexanderâ S. Peregudov、Lidiaâ V. Yashkina、Galinaâ I. Timofeeva、Victorâ I. Maleev、Michael North、Henriâ B. Kagan
DOI:10.1002/adsc.200900523
日期:2009.12
In the presence of chiral catalysts derived from the same chiral hexadentate ligand and aluminium, zinc or titanium ions, the reaction between cyclohexene oxide and trimethylsilyl cyanide can be controlled to give predominantly either the nitrile (up to 99% ee) or the isonitrile product (up to 94% ee). The metal ion, ligand stereochemistry and base concentration all play a role in determining the product