Transition-Metal-Free <i>O</i>-, <i>S</i>-, and <i>N</i>-Arylation of Alcohols, Thiols, Amides, Amines, and Related Heterocycles
作者:Rafael Cano、Diego J. Ramón、Miguel Yus
DOI:10.1021/jo1022052
日期:2011.1.21
A new protocol for the Ullmann-type arylation process of different aromatic heterocycles without any transition-metal catalyst, implying the use of a combination of an excess of potassium hydroxide and dimethyl sulfoxide, is described. The reaction can be performed between a broad range of starting nucleophiles including phenol, alcohols, amines, nitrogen-containing five-membered systems such as pyrazoles, imidazoles, and indoles, and amides with haloarenes, iodide and bromide derivatives giving the best results, the possible pathway involving the in situ generation of the corresponding benzyne intermediate. When the reaction was performed with 2-iodoaniline and either carboxarnides or isothiocyanato derivatives, the corresponding benzoazole derivatives were obtained.
Sequential Direct S<sub>N</sub>Ar Reactions of Pentafluorobenzenes with Azole or Indole Derivatives
作者:Frederik Diness、Mikael Begtrup
DOI:10.1021/ol5012554
日期:2014.6.6
Sequential regioselective N-arylations through high-yielding catalyst-free direct SNAr reactions of pentafluorobenzene derivatives with azole or indole derivatives are described. The N-arylated derivatives were further functionalized through a microwave-assisted cross-coupling reaction via C–H bond activation or Suzuki conditions. The order of the reactions could be reversed, proving full orthogonality
描述了通过五氟苯衍生物与唑或吲哚衍生物的高产率,无催化剂的直接S N Ar反应进行的顺序区域选择性N-芳基化。所述Ñ -arylated衍生物通过通过C-H键活化或Suzuki条件微波辅助交叉偶联反应进一步官能化。反应的顺序可以颠倒,证明反应之间完全正交,从而导致定义明确的完全取代的苯衍生物。