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.
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%.
A readily accessible, active iron catalyst serves in the straightforward, catalytic transferhydrogenation of imines (see scheme). A series of imines are converted into chiral amines in high yields and very good enantioselectivities. This method should find broad application in the search for bioactive chiral amines.
Developing Ru-Catalysts for Asymmetric Transfer Hydrogenation of Acyclic Imines
作者:Dongxu He、Chen Xu、Xiangyou Xing
DOI:10.1021/acs.orglett.2c03385
日期:2022.11.18
Asymmetric transferhydrogenation (ATH) of acyclic imines has been rarely reported by using Ru-based catalysts. In this manuscript, employing Ru-catalysts with minimal stereogenicity in combination with formic acid/triethylamine as the hydrogen donor enables a highly efficient ATH of N-diphenylphosphinyl acyclic imines. These substrates that include various aryl alkyl and heteroaryl alkylsubstituted imines
使用 Ru 基催化剂很少报道无环亚胺的不对称转移氢化 (ATH)。在这份手稿中,使用具有最小立体异构性的 Ru 催化剂与甲酸/三乙胺作为氢供体相结合,可以实现N-二苯基膦基无环亚胺的高效 ATH 。这些包含各种芳基烷基和杂芳基烷基取代亚胺的底物都与该催化体系相容,并以优异的对映体过量 (ee's) 和产率获得相应的还原胺。
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.