Pentafluorophenylammonium Trifluoromethanesulfonimide: Mild, Powerful, and Robust Catalyst for Mukaiyama Aldol and Mannich Reactions between Ketene Silyl Acetals and Ketones or Oxime Ethers
(C6F5N+H3⋅NTf2−) promotes Mukaiyama aldol and Mannich reactions using ketenesilylacetals with ketones and oxime ethers, respectively. The present robust method is mild, but powerful enough to utilize less accessible electrophiles such as enolizable ketones and oxime ethers to produce a variety of β‐hydroxy esters and β‐alkoxyamino esters, respectively. Mechanistic investigation revealed in situ generation
Michaelreactions between trimethylsilyl enolates and α,β-unsaturated carbonyl compounds by using a Lewis base catalyst such as lithium benzamide 4 or lithium succinimide 5 in DMF proceeded smoothl...
An environmentally friendly procedure for Mukaiyama aldol and Mukaiyama–Michael reactions using a catalytic amount of DBU under solvent- and metal-free conditions
作者:Zhi-Liang Shen、Shun-Jun Ji、Teck-Peng Loh
DOI:10.1016/j.tetlet.2004.11.099
日期:2005.1
Mukaiyama aldol and Mukaiyama–Michael reactions can proceed smoothly in the presence of a catalytic amount of DBU (20% mmol), to afford the corresponding products in moderate to good yields. This solvent- and metal-free approach provides an environmentallyfriendly procedure for Mukaiyama reactions.
Tandem Mukaiyama Michael–aldol reactions catalysed by samarium diiodide
作者:Nicolas Giuseppone、Jacqueline Collin
DOI:10.1016/s0040-4020(01)00902-4
日期:2001.10
Samarium diiodide is an efficient precatalyst for tandemMichael–aldolreactions, which allow the formation of two carbon–carbon bonds by successive additions of a ketene silyl acetal and an aldehyde on cyclic α,β-unsaturated ketones. The adducts are isolated as silyl ethers, in good yields, and in some cases with high diastereoselectivities when the reactions are performed at low temperatures. Comparative
Spontaneous aldol and Michael additions of simple enoxytrimethylsilanes in DMSO
作者:Yves Génisson、Liliane Gorrichon
DOI:10.1016/s0040-4039(00)00725-5
日期:2000.6
Activation of simple trimethylsilyl ketene acetals by dipolar aprotic solvents has been evidenced, allowing efficient solvent assisted aldol and Michaeladditions under extremely simple, mild and metal free conditions.