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
New role of tin(II) compounds in organic synthesis
作者:Teruaki Mukaiyama、Shū Kobayashi
DOI:10.1016/0022-328x(90)85213-i
日期:1990.2
new carbon-carbon bond forming reactions by the use of new catalyst systems involving tin(II) compounds are described in this article. The aldol reaction of silyl enol ethers with acetals or aldehydes and the Michael reaction of silyl enol ethers with α,β-unsaturated ketones are catalyzed by the combination of a neutral molecule, trityl chloride, and a weak Lewis acid, tin(II) chloride, under extremely
In the presence of a catalytic amount of trityl perchlorate, 1,5-dicarbonyl compounds, the Michael adducts, are obtained in high yields by the reaction of silyl enol ethers with α,β-unsaturated ketones. The intermediate adducts, the synthetically valuable silyl enol ethers, are also isolated in high yields.