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
Synthetic Studies toward the Tetrapetalones: Diastereoselective Construction of a Putative Intermediate
作者:Wen-Ju Bai、Thomas R. R. Pettus
DOI:10.1021/acs.orglett.7b03500
日期:2018.2.16
A strategy toward tetrapetalones was explored including a site-selective ethylenation of the silyl enol ether A to afford a quaternary stereocenter that serves in a stereogenic capacity. Regio- and diastereoselective reactions were observed in conjunction with the oxidative formation of cation B, which included subsequent selective formation of either carbon–oxygen or carbon–carbon bonds at the δ or
We have developed a practical crossed Claisencondensation between ketene silyl acetals and methyl esters using catalytic NaOH to obtain alpha-monoalkylated beta-keto esters and inaccessible alpha,alpha-dialkylated beta-keto esters.
Synthesis of arylacetates by the palladium-catalyzed cross-coupling of aryl bromides and copper(II) enolates
作者:Fabio Agnelli、Gary A. Sulikowski
DOI:10.1016/s0040-4039(98)01978-9
日期:1998.11
Palladium-catalyzed cross coupling of arylbromides and silylketene acetals in the presence of tributyltin fluoride or copper(II) fluoride is described.
A concise auxiliary-free synthetic route towards tBu-tubuphenylalanine (tBu-Tup) and tBu-epi-tubuphenylalanine (tBu-epi-Tup) has been developed via a diastereoselective Mukaiyama aldol reaction of silyl ketene acetal.