ZrCl<sub>4</sub>-Catalyzed Michael Reaction of 1,3-Dicarbonyls and Enones under Solvent-Free Conditions
作者:Ch. Reddy、G. Smitha、Sujatha Patnaik
DOI:10.1055/s-2005-861837
日期:——
ZrCl4 has been found to catalyze the conjugate addition of 1,3-dicarbonyl compounds with enones. The reaction does not require any solvent and proceeds smoothly at room temperature leading to the corresponding adduct in good yields.
Difluorotris(pentafluoroethyl)phosphorane, (C2F5)(3)PF2, was found to be an active catalyst for the Michael addition reaction of 1,3-beta-diketones or beta-ketoesters (Michael donors) and linear or cyclic unsaturated ketones (Michael acceptors). The reaction proceeds under mild conditions with low catalyst loading and results in the formation of the Michael addition products in moderate to high yields. The developed protocol does not require the use of a base for the in situ generation of a carbanion (Michael donor). (C) 2015 Elsevier B.V. All rights reserved.