Asymmetric Transfer Hydrogenation of 1-Naphthyl Ketones by an ansa-Ru(II) Complex of a DPEN-SO2N(Me)-(CH2)2(η6-p-Tol) Combined Ligand
摘要:
The first second-generation designer Ru(II) catalyst 1b featuring an enantiopure N,C-(N-ethylene-N-methyl-sulfamoyI)-tethered (DPEN-k(2)N,N)/n(6)toluene hybrid ligand Is introduced. Using an SIC 1000 in HCO2H Et3N 5:2 transfer hydrogenation medium, secondary 1-naphthyl alcohols are obtained in up to >99.9% ee under mild conditions. Mechanistic factors are discussed.
Copper(I)‐Catalyzed Enantioconvergent Borylation of Racemic Benzyl Chlorides Enabled by Quadrant‐by‐Quadrant Structure Modification of Chiral Bisphosphine Ligands
作者:Hiroaki Iwamoto、Kohei Endo、Yu Ozawa、Yuta Watanabe、Koji Kubota、Tsuneo Imamoto、Hajime Ito
DOI:10.1002/anie.201906011
日期:2019.8.5
The first copper(I)‐catalyzed enantioselective borylation of racemic benzyl chlorides has been realized by a quadrant‐by‐quadrant structure modulation of QuinoxP*‐type bisphosphine ligands. This reaction converts racemic mixtures of secondary benzyl chlorides into the corresponding chiral benzylboronates with high enantioselectivity (up to 92 % ee). The results of mechanistic studies suggest the formation