Lewis Acid-Promoted Friedel−Crafts Alkylation Reactions with α-Ketophosphate Electrophiles
作者:Austin G. Smith、Jeffrey S. Johnson
DOI:10.1021/ol100410k
日期:2010.4.16
The BF3·OEt2-promoted nucleophilicsubstitution of α-aryl-α-ketophosphates to afford α,α-diaryl ketone products is described. Electron-rich α-ketophosphates perform best, with electron-neutral and electron-poor substrates also tolerated. The reaction is tolerant of a range of aromatic, heteroaromatic, and nonaromatic nucleophiles, with yields ranging from 44% to 84%. Enantioenriched starting material
描述了BF 3 ·OEt 2促进的α-芳基-α-酮磷酸盐的亲核取代,以提供α,α-二芳基酮产物。富含电子的α-酮磷酸酯的性能最佳,同时还可以耐受电子中性和贫电子的底物。该反应可耐受多种芳族,杂芳族和非芳族亲核试剂,收率范围为44%至84%。富含对映体的原料产生外消旋产物,表明通过酰基carb离子的S N 1途径。
Cooperative NHC and Photoredox Catalysis for the Synthesis of 1,4-Dicarbonyl Compounds via Diacylation of Alkenes
intermolecular 1,2-diacylation of alkenes is disclosed via cooperative N-heterocyclic carbene and photoredox catalysis under the mediation of PPh3 and Cs2CO3. This protocol provides a practical approach for construction of 1,4-dicarbonyl compounds toward novel diketone and pharmaceutical derivatives. Furthermore, the regioselective dicarbonyl compounds can be synthesized by adding acyl azolium salt. Mechanistic
在PPh 3和Cs 2 CO 3的介导下,通过协同的N-杂环卡宾和光氧化还原催化烯烃的分子间1,2-二酰化被公开。该协议为向新型二酮和药物衍生物构建 1,4-二羰基化合物提供了一种实用的方法。此外,区域选择性二羰基化合物可以通过添加酰基唑鎓盐来合成。机理研究表明,该过程是酮基自由基与苄基 C-自由基的关键自由基/自由基交叉偶联。
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