Pyridine Group Assisted Addition of Diazo-Compounds to Imines in the 3-CC Reaction of 2-Aminopyridines, Aldehydes, and Diazo-Compounds
作者:Anton V. Gulevich、Victoria Helan、Donald J. Wink、Vladimir Gevorgyan
DOI:10.1021/ol400148r
日期:2013.2.15
A novel three-component coupling (3-CC) reaction of 2-aminoazines, aromatic aldehydes, and diazo-compounds producing polyfunctional β-amino-α-diazo-compounds has been developed. The reaction features an unprecedented heterocycle-assisted addition of a diazo-compound to an imine. The obtained diazoesters were efficiently converted into valuable heterocycles as well as β-amino acid derivatives.
The mixtures of axiallychiral (aR,S)- and (aS,S)-biscarboline alcohols were firstly used as catalysts in enantioselective 1,2- and 1,4-transfer hydrogenations of ketimines and β-enamino esters, respectively. This mixed axiallychiral catalysts exhibited excellent enantioselectivity (up to 98%ee) in the transfer hydrogenations under mild reaction conditions.
aminoacid after dehydrogenation and oxidations using m-CPBA. These diastereoisomers can be obtained by column chromatography and used as catalysts in asymmetric hydrogenation reactions of β-enamine esters and ketimines. Chiral catalysts 6 and 7 exhibited very high enantioselectivity in the reactions. For example, high up to 98%ee was achieved in the enantioselective hydrogenations when only 1%mol of
Regio- and Diastereoselective Radical Hydroboration of <i>N</i>-Aryl Enamine Carboxylates for the Synthesis of <i>anti</i>-β-Amino Organoborons
作者:Jinjin Zhao、Yeelin Phang、Zhijuan Wang、Fentahun Wondu Dagnaw、Yi-Hong Lu、Yi-Feng Wang、Ji-Kang Jin
DOI:10.1021/acs.orglett.3c00818
日期:2023.4.28
regio- and diastereoselective hydroboration of N-aryl enamine carboxylates was achieved by dichloro-substituted N-heterocyclic carbene (NHC)-boryl radical to access the valuable anti-β-amino boron skeleton. Excellent diastereoselectivity (>95:5 dr) was obtained using dichloro-NHC–BH3 (boryl radical precursor) and the thiol catalyst. Broad substrate scope and good functional group tolerance were demonstrated
Cobalt-catalyzed hydrogenation of β-enamino esters using an internal mixture of bidentate and monodentate ligands
作者:Manuel Amézquita-Valencia、Armando Cabrera
DOI:10.1016/j.jorganchem.2014.06.028
日期:2014.10
Different beta-amino esters have been obtained in good yields by means of octacarbonyldicobalt-catalyzed hydrogenation of beta-enamine esters in the presence of mixture of a bidentate phosphine chiral (R-BINAP) and a monodentate phosphine achiral (PPh3). Likewise, a non-symmetric Co/BINAP/PPh3 complex was isolated. This new compound was used in the hydrogenation reaction under different conditions and the results suggest that this heterocombination could be responsible for improving enantiomeric excess in the reduction products. (C) 2014 Elsevier B.V. All rights reserved.