Neutral Lewis Bases as Activators of Molecular Sieves in the Conjugate Addition of 1,3-Dicarbonyl Compounds
作者:Arrigo Scettri、Rosaria Villano
DOI:10.1055/s-2005-861810
日期:——
The catalytic properties of 3 A molecular sieves in the promotion of Michael addition of 1,3-dicarbonyl compounds are significantly improved by activation with several neutral Lewisbases. Comparable efficiency can be observed under solvent-free conditions.
reactions such as Michael and aldol reactions in aqueous media and the H−D exchange reactions using deuterium oxide. For example, a 200-mmol-scale Michael reaction under triphasic conditions proceeded rapidly, with an extremely high turnover number of up to 260 400 and an excellent turnover frequency of 48 s-1. No vanadium leaching was detected during the above reactions, and the catalyst was readily recycled
Cerium(III) chloride heptahydrate in the presence of sodium iodide catalyses the Michael addition of 1,3-dicarbonyl compounds to α,β-unsaturated ketones and α,β-unsaturated aldehydes with extraordinary efficiency. The very mild conditions allow high chemoselectivity as shown by the absence of the typical side reactions, which can be observed in the conventional base-catalyzed processes. More interestingly
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.
Solvent free reaction under microwave irradiation: A new procedure for Eu+3 — Catalyzed Michael addition of 1,3-dicarbonyl compounds
作者:Annunziata Soriente、Aldo Spinella、Margherita De Rosa、Manuela Giordano、Arrigo Scettri
DOI:10.1016/s0040-4039(96)02294-0
日期:1997.1
CC bond formation via Michael addition is achieved in high yields and short times by employing catalytic amounts of EuCl3 in dry media undermicrowaveirradiation.