Synthesis of Air- and Moisture-Stable, Storable Chiral Oxorhenium Complexes and Their Application as Catalysts for the Enantioselective Imine Reduction
salicyloxazoline based oxorhenium(V) complexes have been synthesized and their catalytic application for the asymmetricreduction of ketimines using hydrosilane as hydride source is disclosed. A broad substrate scope, high yields, and excellent enantioselectivities (up to 99 %) are attained. Furthermore, the syntheses of enantiopure α‐amino esters, γ‐ and δ‐lactams, and isoindolinones have also been carried
合成了空气/水分稳定,晶体和可储存的手性水杨基恶唑啉基氧化(V)配合物,并公开了其在氢化硅烷作为氢化物源的情况下催化不对称还原酮亚胺的催化应用。获得了广泛的底物范围,高收率和出色的对映选择性(最高99%)。此外,对映体纯α-氨基酯,γ-和δ-内酰胺以及异吲哚啉酮的合成也已使用该方法进行。最后,该方法已应用于具有药物相关性的合成靶标,例如R -(+)-沙丁胺碱和R -(+)-crispine A.
Enantioselective Strecker Reaction of Phosphinoyl Ketoimines Catalyzed by in Situ Prepared Chiral <i>N</i>,<i>N</i>‘-Dioxides
The enantioselectiveStreckerreaction of N-diphenylphosphinoyl ketoimines has been achieved by use of in situ prepared chiral N,N‘-dioxide catalyst from l-piperidinamide 3f and m-chloroperoxybenzoic acid (m-CPBA). Excellent yields (up to 99%) and high enantioselectivities (up to 92% ee) were obtained. In particular, in situ prepared catalyst with readily available chiral material made the procedure
Asymmetric catalysis: A facileenantioselective Strecker reaction of ketimines with trimethylsilyl cyanide (TMSCN) was realized by employing chiral (S)‐BNPNa 3 e and PBAP as an additive (see image). A wide substrate scope and good‐to‐excellent enantioselectivities were achieved.
Asymmetric Transfer Hydrogenation of Ketimines Using Well-Defined Iron(II)-Based Precatalysts Containing a PNNP Ligand
作者:Alexandre A. Mikhailine、Mazharul I. Maishan、Robert H. Morris
DOI:10.1021/ol302079q
日期:2012.9.7
complexes containing PNNP ligands catalyze a highly enantioselective reduction of N-(diphenylphosphinoyl)- and N-(p-tolylsulphonyl)-ketimines. Under mild conditions and low catalyst loading, the ketimines are successfully reduced to the corresponding amines in enantiomeric excess ranging from 94 to 99%.
Zinc-Catalyzed Enantioselective Hydrosilylation of Ketones and Imines under Solvent-Free Conditions
作者:Marcin Szewczyk、Agata Bezłada、Jacek Mlynarski
DOI:10.1002/cctc.201601140
日期:2016.12.7
The zinc acetate promoted asymmetric hydrosilylation of various ketones and imines under solvent‐free conditions was examined by using an unprecedented low catalyst loading. Exposure of ketones to 0.05 mol % Zn‐based chiral diamine complex in the presence of triethoxysilane afforded enantioenriched alcohols in excellent yields (up to 98 %) and enantioselectivities (up to 97 % ee). This methodology