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 Hydrosilylation of Imines Catalyzed by Chiral Zinc Acetate Complexes
作者:Agata Bezłada、Marcin Szewczyk、Jacek Mlynarski
DOI:10.1021/acs.joc.5b02613
日期:2016.1.4
A series of zinc acetate complexes with optically pure diphenylethanediamine (DPEDA)-derived ligands have been employed as enantioselectivecatalyst for the hydrosilylation of various imines. High control of stereoselectivity (up to 97% ee) and excellent yields (up to 96%) were gained for a broad range of N-phosphinoylimines by using (R,R)-N,N′-dibenzyl-1,2-diphenylethane-1,2-diamine. This is the first
Reaction prospecting by 31P NMR: enantioselective rhodium-DuPhos catalysed addition of ZnMe2 to diphenylphosphinoylimines
作者:Rosemary H. Crampton、Samir El Hajjaji、Martin E. Fox、Simon Woodward
DOI:10.1016/j.tetasy.2009.09.020
日期:2009.11
Chiral shift P-31 NMR spectroscopy allows the identification of ligand leads in asymmetric catalyst systems for ZnMe2 addition to ArCH=NP(C)Ph-2. Subsequent GC-based optimisation shows [RhC](CH2=CH2)(2)](2) and (RR)-MeDuPhos to be the optimal pre-catalyst combination (product in 78-93% ee). Transmetallation of [(MeDuPhos)RhN(P(O)Ph-2-CHMeAr}] with ZnMe2 appears to be the rate limiting step of the catalytic cycle as competing coordination by the imine starting material leads to Ph2P(O)NHCH2Ar via MVP hydrogen-transfer. This limitation can largely be overcome by the slow addition of the imine. (C) 2009 Elsevier Ltd. All rights reserved.