Expanding the Scope of Lewis Acid Catalysis in Water: Remarkable Ligand Acceleration of Aqueous Ytterbium Triflate Catalyzed Michael Addition Reactions.

Abstract

Addition reactions O 0060Expanding the Scope of Lewis Acid Catalysis in Water: Remarkable Ligand Acceleration of Aqueous Ytterbium Triflate Catalyzed Michael Addition Reactions. -Addition of TMEDA to Yb(O-Tf)3 enables highly efficient Michael addition reaction in water. -(DING, R.; KATEBZADEH, K.; ROMAN, L.; BERGQUIST, K.-E.; LINDSTROEM*, U. M.; J. Org. Chem. 71 (2006) 1, 352-355; Dep. Org. Chem., Univ. Lund, S-221 00 Lund, Swed.; Eng.) -Jannicke 21-036

Green Chemical Technologies

“…However, one way to overcome this is by using a water-stable molecular Lewis acid such as ytterbium or scandium triflate (Ding et al, 2006). It was recently discovered that rate enhancements could be achieved by adding small amounts of ligand to ytterbium triflate-catalyzed Michael addition reactions in water (Ding et al, 2006). Although in this study a recycling study on the catalyst was not performed, it is likely that these species can be easily recycled in a similar way to related nitration catalysts previously reported (Waller et al, 1997).…”

“…Therefore, on an industrial scale they can lead to considerable waste. However, one way to overcome this is by using a water-stable molecular Lewis acid such as ytterbium or scandium triflate (Ding et al, 2006). It was recently discovered that rate enhancements could be achieved by adding small amounts of ligand to ytterbium triflate-catalyzed Michael addition reactions in water (Ding et al, 2006).…”