Nickel(0)-Catalyzed Enantioselective Annulations of Alkynes and Arylenoates Enabled by a Chiral NHC Ligand: Efficient Access to Cyclopentenones
作者:Joachim S. E. Ahlin、Pavel A. Donets、Nicolai Cramer
DOI:10.1002/anie.201408364
日期:2014.11.24
nickel‐catalyzed reductive [3+2] cycloaddition of α,β‐unsaturated aromatic esters and alkynes constitutes an efficient method for their synthesis. Here, nickel(0) catalysts comprising a chiral bulky C1‐symmetric N‐heterocyclic carbene ligand were shown to enable an efficient asymmetric synthesis of cyclopentenones from mesityl enoates and internal alkynes under mild conditions. The bulky NHC ligand
Chiral N-Heterocyclic Carbene Gold Complexes: Synthesis, Properties, and Application in Asymmetric Catalysis
作者:Dipshikha Banerjee、Andrea K. Buzas、Céline Besnard、E. Peter Kündig
DOI:10.1021/om300917m
日期:2012.12.10
Nine new N-heterocycliccarbenegold chloride complexes (10–18) were synthesized starting from bulky chiral imidazoliumsalts (1–9) developed in this laboratory. Full characterization of all complexes, including the X-ray structures of gold(I)(1,3-bis((S)-1-(2-methoxyphenyl)-2,2-dimethylpropyl)-1H-imidazol-2(3H)-ylidene) chloride (13) and gold(I)(1,3-bis((S)-2,2-dimethyl-1-(naphthalen-1-yl)propyl)
Chiral PEPPSI Complexes: Synthesis, Characterization, and Application in Asymmetric Suzuki–Miyaura Coupling Reactions
作者:Laure Benhamou、Céline Besnard、E. Peter Kündig
DOI:10.1021/om4009982
日期:2014.1.13
PEPPSI complexes incorporating chiral N-heterocyclic carbene (NHC) ligands based on 2,2-dimethyl-1-(o-substituted aryl)-propan-1-amines were synthesized. Two complexes, with one saturated and one unsaturated NHC ligand, were structurally characterized. The chiral PEPPSI complexes were used in asymmetric Suzuki-Miyaura reactions, giving atropisomeric biaryl products in modest to good enantiomeric ratios.