Trimethylsilyl trifluoromethanesulfonate-catalyzed aldol reaction of various aldehydes with silyl enol ethers.
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چکیده
منابع مشابه
An efficient catalyst-free Mukaiyama-aldol reaction of fluorinated enol silyl ethers with tryptanthrin.
We report an efficient Mukaiyama-aldol reaction of tryptanthrin with fluorinated enol silyl ethers, which is carried out in methanol without the use of any catalyst. This method is applied to the total synthesis of the difluoro analogues of the natural product Phaitanthrin B.
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We describe here a Tf₂NH-catalyzed formal (3+3) cycloaddition of silyl enol ethers with acrylates as a new domino reaction. In the domino sequence, the catalyst activates Michael addition, deprotonation of the resulting silyloxonium cation and intramolecular Claisen condensation. It was found that reaction modes significantly depend on the reaction temperature. We also examined the mechanistic ...
متن کاملAcetic acid aldol reactions in the presence of trimethylsilyl trifluoromethanesulfonate.
In the presence of TMSOTf and a trialkylamine base, acetic acid undergoes aldol addition to non-enolizable aldehydes under exceptionally mild conditions. Acidic workup yields the beta-hydroxy carboxylic acid. The reaction appears to proceed via a three-step, one-pot process, including in situ trimethylsilyl ester formation, bis-silyl ketene acetal formation, and TMSOTf-catalyzed Mukaiyama aldol...
متن کاملGold-catalyzed alkylation of silyl enol ethers with ortho-alkynylbenzoic acid esters
Unprecedented alkylation of silyl enol ethers has been developed by the use of ortho-alkynylbenzoic acid alkyl esters as alkylating agents in the presence of a gold catalyst. The reaction probably proceeds through the gold-induced in situ construction of leaving groups and subsequent nucleophilic attack on the silyl enol ethers. The generated leaving compound abstracts a proton to regenerate th...
متن کاملA highly diastereoselective “super silyl” governed aldol reaction: synthesis of α,β-dioxyaldehydes and 1,2,3-triols
A highly diastereoselective approach for the synthesis of protected a,b-dioxyaldehydes derived from (Z)tris(trimethylsilyl)silyl “super silyl” enol ethers is described. A general and highly syn-stereoselective aldol reaction directed by the “super silyl” group catalyzed by triflimide (HNTf2) is developed providing a,bdioxyaldehydes and 1,2,3-triol fragments which can be a useful platform for th...
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ژورنال
عنوان ژورنال: Chemical and Pharmaceutical Bulletin
سال: 1990
ISSN: 0009-2363,1347-5223
DOI: 10.1248/cpb.38.1509