192461-85-1Relevant academic research and scientific papers
Enantioselective Hydrogenation of Activated Aryl Imines Catalyzed by an Iron(II) P-NH-P′ Complex
Seo, Chris S. G.,Tannoux, Thibault,Smith, Samantha A. M.,Lough, Alan J.,Morris, Robert H.
, p. 12040 - 12049 (2019/10/02)
Chiral amines are key building blocks in synthetic chemistry with numerous applications in the agricultural and pharmaceutical industries. Asymmetric imine hydrogenation, particularly with iridium catalysts, is well developed. However, imine reduction still remains challenging in the context of replacing such a precious metal with a cheap, nontoxic, and environmentally friendly substitute such as iron. Here, we report that an unsymmetrical iron P-NH-P′ catalyst that was previously shown to be effective for the asymmetric hydrogenation of aryl ketones is also a very effective catalyst for the asymmetric hydrogenation of prochiral aryl imines activated with N-diphenylphosphinoyl or N-tosyl groups. The P-NH-P′ abbreviation stands for (S,S)-PPh2CHPhCHPhNHCH2CH2PiPr2. Density functional theory results suggest that, surprisingly, the NH group on the catalyst activates and orients the imine to hydride attack by hydrogen bonding to the PO or SO group on the imine nitrogen, as opposed to the imine nitrogen itself. This may explain why N-Ph and N-Bu imines are not hydrogenated.
Enantioselective Hydrosilylation of Imines Catalyzed by Chiral Zinc Acetate Complexes
Bez?ada, Agata,Szewczyk, Marcin,Mlynarski, Jacek
, p. 336 - 342 (2016/01/15)
A series of zinc acetate complexes with optically pure diphenylethanediamine (DPEDA)-derived ligands have been employed as enantioselective catalyst 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 successful application of an air-stable and environmentally friendly chiral Zn(OAc)2 complex instead of the previously used harmful diethylzinc in the asymmetric reduction of the C=N double bond.
Convenient, enantioselective hydrosilylation of imines in protic media catalyzed by a Zn-trianglamine complex
Gajewy, Jadwiga,Gawronski, Jacek,Kwit, Marcin
scheme or table, p. 3863 - 3870 (2011/06/23)
Chiral hexamine macrocycle derived from trans-1,2-diaminocyclohexane (DACH) in a complex with diethylzinc efficiently catalyzes the asymmetric hydrosilylation of N-phosphorylated aryl-alkyl or aryl-aryl ketimines in protic media with enantiomeric excess o
Chloroform is not solvent but activator for cobalt complex catalyst of enantioselective borohydride reduction
Kokura, Ai,Tanaka, Saiko,Teraoka, Haruna,Shibahrara, Atsushi,Ikeno, Taketo,Nagata, Takushi,Yamada, Tohru
, p. 26 - 27 (2007/10/03)
For the enantioselective borohydride reduction of carbonyl compounds catalyzed by the optically active ketoiminatocobalt complexes, chloroform has been employed as a unique solvent for achieving a high enantioselectivity, whereas it was found that a catal
Zinc-catalyzed enantioselective hydrosilylation of imines
Park, Bu-Mahn,Mun, Soungyun,Yun, Jaesook
, p. 1029 - 1032 (2007/10/03)
The highly enantioselective reduction of imines is achieved by employing chiral Zn/diamine catalysts. This new catalytic protocol offers attractive features such as use of a non-precious metal and an inexpensive silane, easy modification of chiral diamine
Enantioselective reduction of imines catalyzed by a rhenium(V)-oxo complex
Nolin, Kristine A.,Ahn, Richard W.,Toste, F. Dean
, p. 12462 - 12463 (2007/10/03)
An air- and moisture-tolerant enantioselective hydrosilylation of N-phosphinyl imines employing a chiral Re(V)-oxo complex as a catalyst is described. The chiral catalyst is a cyanobis(oxazoline) (CNbox)-ligated rhenium-oxo complex of the general formula
Enantioselective borohydride reduction catalyzed by optically active cobalt complexes
Yamada, Tohru,Nagata, Takushi,Sugi, Kiyoaki D.,Yorozu, Kiyotaka,Ikeno, Taketo,Ohtsuka, Yuhki,Miyazaki, Daichi,Mukaiyama, Teruaki
, p. 4485 - 4509 (2007/10/03)
The highly enantioselective borohydride reduction of aromatic ketones or imines to the corresponding alcohols was developed in the presence of a catalytic amount of an optically active cobalt(II) complex catalyst. This enantioselective reduction is carried out using a precisely premodified borohydride with alcohols such as tetrahydrofurfuryl alcohol, ethanol and methanol. High optical yields are obtained by choosing the appropriate alcohol as modifiers and a suitable β-ketoiminato ligand of the catalyst. The enantioselective borohydride reduction has been successfully applied to the preparation of optically active 1,3-diols, the stereoselective reduction of diacylferrocenes, and dynamic and/or kinetic resolution of 1,3-dicarbonyl compounds.
Enantioselective borohydride reduction of N-diphenylphosphinyl imines using optically active cobalt(II) complex catalysts
Sugi, Kiyoaki D.,Nagata, Takushi,Yamada, Tohru,Mukaiyama, Teruaki
, p. 493 - 494 (2007/10/03)
The enantioselective borohydride reduction using optically active cobalt(II) complex catalysts was successfully applied to various aryl N-diphenylphosphinyl imines, and the corresponding reduced products were obtained in good yields with high enantiomeric excesses (up to 99% ee). The optically active primary amines were obtained by the successive hydrolysis under mild conditions.
