We herein report nitroxyl-radical catalyst 1a, which recognizes the electronic properties of silyl ethers, thus enabling selective oxidation of benzylic and allylic silyl ethers, despite steric factors. A subsequent one-pot reduction accomplishes the formal deprotection to the corresponding benzylic and allylic alcohols. This catalytic system allows the direct oxidative desymmetrization of bis-benzylic and bis-allylic silyl ethers to access synthetically useful monoprotected conjugated aldehydes, which can be applied to one-pot enantioselective transformations. Mechanistic studies revealed that the highly electron-accepting oxoammonium species from 1a as well as the trifluoroacetate form of phenyl iodonium bis(trifluoroacetate) (PIFA) play key roles for the selectivity-determining hydride transfer step.

中文翻译：

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通过有机催化氧化对苯甲基和烯丙基硅醚进行多种位点选择性转化

我们在此报告了硝酰自由基催化剂1a，它识别甲硅烷基醚的电子特性，从而能够选择性氧化苄基和烯丙基甲硅烷基醚，尽管存在空间因素。随后的一锅还原完成了相应苯甲醇和烯丙醇的正式脱保护。该催化系统允许双苄基和双烯丙基甲硅烷基醚直接氧化去对称，以获得合成上有用的单保护共轭醛，其可应用于一锅对映选择性转化。机理研究表明， 1a中的高电子接受性氧铵物质以及三氟乙酸盐形式的苯基碘鎓双(三氟乙酸盐) (PIFA) 在决定选择性的氢化物转移步骤中发挥着关键作用。