TY - JOUR
T1 - Chiral Bimetallic Catalysts Derived from Chiral Metal Phosphates
T2 - Enantioselective Three-Component Asymmetric Aza-Diels-Alder Reactions of Cyclic Ketones
AU - Deng, Yongming
AU - Karunaratne, Chamini V.
AU - Csatary, Erika
AU - Tierney, David L.
AU - Wheeler, Kraig
AU - Wang, Hong
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/8/21
Y1 - 2015/8/21
N2 - A new type of chiral bimetallic catalyst is disclosed. These chiral bimetallic catalysts are easily formed through mixing a metal Lewis acid and a metal binaphthyl phosphate (MLA/M[P]3) in solution. 1H and 31P NMR spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, and X-ray crystallographic analysis reveal a bimetallic structure of the Y(Yb)III/Y[P]3 complexes with bridging binaphthyl phosphate ligands. The Lewis acidity of these chiral bimetallic catalysts is readily tuned by changing either the metal Lewis acid or the chiral metal phosphate. Through cooperative metal Lewis acid-enamine catalysis, asymmetric three-component aza-Diels-Alder reactions of 5-, 6-, and 7-membered cyclic ketones, unsaturated ketoesters, and arylamines were successfully achieved to afford fused bicyclic dihydropyridines in high yields (up to 94%) with high enantioselectivity (up to 99% enantiomeric excess) and excellent chemoselectivity.
AB - A new type of chiral bimetallic catalyst is disclosed. These chiral bimetallic catalysts are easily formed through mixing a metal Lewis acid and a metal binaphthyl phosphate (MLA/M[P]3) in solution. 1H and 31P NMR spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, and X-ray crystallographic analysis reveal a bimetallic structure of the Y(Yb)III/Y[P]3 complexes with bridging binaphthyl phosphate ligands. The Lewis acidity of these chiral bimetallic catalysts is readily tuned by changing either the metal Lewis acid or the chiral metal phosphate. Through cooperative metal Lewis acid-enamine catalysis, asymmetric three-component aza-Diels-Alder reactions of 5-, 6-, and 7-membered cyclic ketones, unsaturated ketoesters, and arylamines were successfully achieved to afford fused bicyclic dihydropyridines in high yields (up to 94%) with high enantioselectivity (up to 99% enantiomeric excess) and excellent chemoselectivity.
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U2 - 10.1021/acs.joc.5b00895
DO - 10.1021/acs.joc.5b00895
M3 - Article
AN - SCOPUS:84939826434
SN - 0022-3263
VL - 80
SP - 7984
EP - 7993
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
IS - 16
ER -