Pentafluorophenylammonium Trifluoromethanesulfonimide: Mild, Powerful, and Robust Catalyst for Mukaiyama Aldol and Mannich Reactions between Ketene Silyl Acetals and Ketones or Oxime Ethers
作者:Ryohei Nagase、Jun Osada、Hiroaki Tamagaki、Yoo Tanabe
DOI:10.1002/adsc.200900869
日期:——
(C6F5N+H3⋅NTf2−) promotes Mukaiyama aldol and Mannich reactions using ketene silyl acetals 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
Pentafluorophenylammonium三氟甲磺酰亚胺(C 6 ˚F 5 Ñ + ħ 3 ⋅NTf 2 - )促进向山羟醛和使用甲硅烷基烯酮缩醛与酮和肟醚,分别曼尼希反应。目前的稳健方法虽然温和,但功能强大,足以利用较难接近的亲电子试剂(例如可烯化的酮和肟醚)分别生产各种β-羟基酯和β-烷氧基氨基酯。机理研究表明,真正的活性催化剂原位生成了三甲基甲硅烷基双硫酰亚胺[Tf 2 N(TMS)],并通过合理的1 H NMR测量得到了证实。