Synthesis and characterization of a new C2-symmetrical chiral tridentate N-heterocyclic carbene ligand coordinated Cr(III) complex
摘要:
The preparation of a new C-2-symmetrical chiral tridentate N-heterocyclic carbene (NHC) ligand coordinated Cr(III) complex is described. The new NHC ligand was prepared as its AgBr complex, which was stable but smoothly underwent carbene exchange reaction with CrCl2 to afford the new NHC ligand coordinated Cr(III) complex. The X-ray crystallographic analysis of the Cr(III) complex revealed its distorted octahedral form. The Cr(III) complex mediated reaction of allylbromide with benzaldehyde did not afford products under the catalytic conditions reported by us. (C) 2015 Elsevier Ltd. All rights reserved.
A new C2-symmetric azolium compound for Cu-catalyzed asymmetric conjugate addition of R2Zn to cyclic enone
作者:Ayako Harano、Satoshi Sakaguchi
DOI:10.1016/j.jorganchem.2010.07.038
日期:2011.1
A new chiral N-heterocyclic carbene (NHC) ligand was designed. Thus, an efficient synthetic route to C2-symmetric bis(hydroxyamide)-functionalized benzimidazolium salts from chiral β-amino alcohols was developed. The combination of Cu(OTf)2 and the chiral azolium compound efficiently promoted the conjugate addition reaction of cyclic enone with dialkylzinc to give the corresponding adduct in good yield