title: An efficient organocatalytic method for highly enantioselective Michael addition of malonates to enones catalyzed by readily accessible primary amine-thiourea.
abstract: A practical and highly enantioselective Michael addition of malonates to enones catalyzed by simple and readily available bifunctional primary amine-thiourea derived from 1,2-diaminocyclohexane is reported. The addition of weak acids and elevated temperature (ca. 50 °C) improved the efficiency of the Michael reaction. This approach enables the efficient synthesis of 1,5-ketoesters with good yields, excellent enantioselectivities (up to 99% ee), and low loading (0.5-5 mol %) of simple chiral primary amine-thiourea catalysts, and is applicable in multigram scale synthesis.
authors.affiliation: Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Dudziński
authors.forename: Anna M
authors.initials: AM
authors.lastname: Pakulska
authors.forename: Piotr
authors.initials: P
authors.lastname: Kwiatkowski