Regioselective formation of 2-alkoxyoxetanes in the photoreaction of aromatic carbonyl compounds with β,β-dimethyl ketene silyl acetals: notable solvent and silyl group effects
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
Sodium Phenoxide−Phosphine Oxides as Extremely Active Lewis Base Catalysts for the Mukaiyama Aldol Reaction with Ketones
作者:Manabu Hatano、Eri Takagi、Kazuaki Ishihara
DOI:10.1021/ol702052r
日期:2007.10.1
A highly efficient Mukaiyama aldolreaction between ketones and trimethylsilyl enolates catalyzed by sodium phenoxide-phosphine oxides as simple homogeneous Lewis base catalysts (0.5-10 mol %) was developed, which minimized competing retro-aldolreaction. For a variety of aromatic ketones and aldimines, aldol and Mannich-type products with an alpha-quaternary carbon center were obtained in good to