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DOI: 10.1055/s-2007-968402
A Water-Compatible Catalyst for the Michael Reaction of Ketones to Nitroolefins
Contributor(s):Benjamin List, Subhas Chandra PanIndian Institute of Technology Kanpur, India
Highly Enantioselective Water-Compatible Organocatalyst for Michael Reaction of Ketones to Nitroolefins
Org. Lett. 2007, 9: 1117-1119
Publication History
Publication Date:
24 April 2007 (online)
Key words
Michael reaction - nitroolefins - diamine catalysis - enantioselectivity
Significance
A new diamine catalyst has been developed for the asymmetric Michael reaction of cyclic ketones to nitroolefins. The catalyst is water-compatible and highly effective for the Michael reaction with nitroolefins when used in combination with TFA. With 10 mol% of catalyst 1 moderate to high diastereoselectivities (dr = 77:23 to 98:2) and enantioselectivities (er = 87:13 to 99.5:0.5) are obtained for different aromatic and heteroaromatic nitroolefins. A non-aromatic cyclohexyl nitroolefin has also been used with high enantioselectivity (er = 94:6).
Comment
Recently, the Michael reaction of ketones to nitroolefins has been studied extensively by different groups (see reviews below). Here the authors have succeeded in introducing a new catalyst which works both in the presence of water and also in a wide range of organic solvents. The binaphthyl group in catalyst 1 enhances the hydrophobic hydration when the reaction is conducted in an aqueous medium and also helps to use organic solvent due to its aromatic nature.
Reviews
S. B. Tsogaeva Eur. J. Org. Chem. 2007, 11, 1701-1716; S. Sulzer-Mossé, A. Alexakis Chem. Commun. 2007, DOI: 10.1039/b701216k.