Mild and Efficient Pentafluorophenylammonium Triflate (PFPAT)-Catalyzed C-Acylations of Enol Silyl Ethers or Ketene Silyl (Thio)Acetals with Acid Chlorides
作者:Akira Iida、Jun Osada、Ryohei Nagase、Tomonori Misaki、Yoo Tanabe
DOI:10.1021/ol070191b
日期:2007.5.1
A pentafluorophenylammonium triflate (PFPAT) catalyst (5 mol %) successfully promoted C-acylation of enol silyl ethers with acid chloride to produce various beta-diketones (12 examples; 62-92% yield). Similarly, C-acylation of ketene silyl acetals or ketene silyl thioacetals (i.e., crossed Claisen condensation) proceeded smoothly to provide not only alpha-monoalkylated beta-keto (thio)esters but also
五氟苯基三氟甲磺酸铵(PFPAT)催化剂(5摩尔%)成功地促进了烯丙基甲硅烷基醚与酰氯的C-酰化反应,从而制得各种β-二酮(12例;产率62-92%)。类似地,乙烯酮甲硅烷基缩醛或乙烯酮甲硅烷基硫缩醛的C-酰化反应(即,交叉克莱森缩合反应)进行得很顺利,不仅提供了α-单烷基化的β-酮(硫)酯,而且还提供了热力学上不利的(较难获得的)α,α-二烷基化的β -酮基(硫代)酯具有良好至优异的收率(38个实例; 60-92%的收率)。