Abstract
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. (1)H and (31)P 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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.