Enantioselective Diels-Alder Reactions: Effect of the Achiral Template on Reactivity and Selectivity
作者:Mukund Sibi、Jianxie Chen、Levi Stanley
DOI:10.1055/s-2007-968014
日期:2007.2
Several achiral templates have been evaluated in chiral Lewis acid mediated enantioselective Diels-Alder reactions. Templates such as pyrrolidinones and pyrazolidinones that are capable of forming six-membered chelates with the Lewis acid exhibited the best reactivity and highest selectivity.
Design of a Small-Molecule Catalyst Using Intramolecular Cation−π Interactions for Enantioselective Diels−Alder and Mukaiyama−Michael Reactions: <scp>l</scp>-DOPA-Derived Monopeptide·Cu(II) Complex
作者:Kazuaki Ishihara、Makoto Fushimi
DOI:10.1021/ol060651l
日期:2006.4.1
[reaction: see text] We have designed a small-molecule artificial metalloenzyme that is prepared in situ from Cu(OTf)(2) or Cu(NTf(2))(2) (1.0 equiv) and l-DOPA-derived monopeptide (1.1 equiv). This catalyst (2-10 mol %) is highly effective for the enantioselectiveDiels-Alder (DA) and Mukaiyama-Michael (MM) reactions with alpha,beta-unsaturated 1-acyl-3,5-dimethylpyrazoles. The present results demonstrate