通过在2-甲基四氢呋喃(2-MeTHF)中使用廉价的聚甲基氢硅氧烷,开发了通过MeSiH 3原位形成的α-酮酰胺的Cs 2 CO 3催化的氢化硅烷化反应。将由苯胺和烷基胺制得的各种芳基和烷基α-酮酰胺置于氢化硅烷化条件下,以中等至极好的收率得到α-羟基酰胺。将该无过渡金属的方案应用于化学选择性氢化硅烷化反应,其中与简单酮相比,α-酮酰胺官能团的羰基发生还原,并进一步扩展至克级规程。
A catalyst‐ and additive‐free chemoselective transfer hydrogenation of α‐keto amides to α‐hydroxy amides is easily achieved by using sodium formate as a hydrogen source. Control experiments suggest that the NH group of α‐keto amides is crucial for the chemoselective reduction through the formation of hydrogen bonds.
TiCl<sub>4</sub>/<i>tert</i>-Butyl Hydroperoxide: Chemioselective Oxidation of Secondary Alcohols and Suppression of Sharpless Epoxidation
作者:Kuangsen Sung、Chun-Tin Shei、Hao-Lun Chien
DOI:10.1055/s-2008-1066997
日期:——
Replacing Ti(Oi-Pr)4 with TiCl4 under the normal Sharpless epoxiation conditions resulted in a shut down of the epoxidation reaction. Instead, a chemioselective oxidation of secondary alcohols in the presence of primary alcohols occurred.
Hydrogenation of the Carbonyl Group in α-Ketoesters and α-Ketoamides Catalyzed by Ruthenium Clay
作者:Raluca Aldea、Howard Alper
DOI:10.1021/jo981447h
日期:1998.12.1
Ruthenium clay, prepared by reaction of RuCl3. H2O with the 3-phosphinopropyl ligand anchored on Fluka K10 montmorillonite, is an effective catalyst for the reduction of the ol-carbonyl group of alpha-ketoesters and alpha-ketoamides (50-89% yield).
Generation of Carbamoyl- and Thiocarbamoyllithium Synthons Having a Hydrogen(s) or an Aryl Group on the Nitrogen and Their Trapping with Carbonyl Electrophiles
Dimetalated amides 1 (Y = O) were generated as the synthons of carbamoyllithiums 2 (Y = O) by the reaction of isocyanates with iBu2AlTenBu and a subsequent tellurium-lithium exchange reaction. A series of amide derivatives 3 (Y = O) were obtained by the trapping of dianion 1 with electrophiles. This transformation can be successfully applied to the generation and trapping of thiocarbamoyllithium synthons 1 (Y = S) as well as to the nucleophilic introduction of the parent carbamoyl moiety H2NC(O).
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作者:I. V. Mashevskaya、M. I. Vakhrin、V. A. Safin、I. A. D'yakova、M. A. Nikiforova、S. Yu. Solodnikov、L. V. Anikina