Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA.
J Am Chem Soc. 2010 Dec 8;132(48):17092-5. doi: 10.1021/ja1086547. Epub 2010 Nov 15.
A strategy for the ortho-silylation of aryl ketone, benzaldehyde, and benzyl alcohol derivatives has been developed in which a hydroxyl group formally serves as the directing element for Ir-catalyzed arene C-H bond activation. One-pot generation of a (hydrido)silyl ether from the carbonyl compound or alcohol is followed by dehydrogenative cyclization at 80-100 °C in the presence of norbornene as a hydrogen acceptor and the combination of 1 mol % [Ir(cod)OMe]2 and 1,10-phenanthroline as a catalyst to form benzoxasiloles. The synthetic utility of the benzoxasilole products is demonstrated by conversion to phenol or biaryl derivatives by Tamao-Fleming oxidation or Hiyama cross-coupling. Both of these transformations of the C-H silylation products exploit the Si-O bond in the system and proceed by activation of the silyl moiety with hydroxide, rather than fluoride.
已开发出一种芳基酮、苯甲醛和苄醇衍生物的邻硅烷基化策略，其中羟基形式上充当 Ir 催化芳基 C-H 键活化的导向基团。在羰基化合物或醇存在下，一锅法生成（氢）硅醚，然后在降冰片烯作为氢受体和 1 mol% [Ir(cod)OMe]2 和 1,10-菲咯啉的组合存在下，在 80-100°C 下进行脱氢环化，形成苯并氧硅杂环戊烯。苯并氧硅杂环戊烯产物的合成实用性通过 Tamao-Fleming 氧化或 Hiyama 交叉偶联转化为苯酚或联芳基衍生物来证明。这两种 C-H 硅烷基化产物的转化都利用了系统中的 Si-O 键，并且通过用氢氧根离子而非氟离子激活硅烷基部分来进行。
