The mechanism of N-vinylindole formation via tandem imine formation and cycloisomerisation of o-ethynylanilines
作者:Danielle F. Kennedy、Ainara Nova、Anthony C. Willis、Odile Eisenstein、Barbara A. Messerle
DOI:10.1039/b915269e
日期:——
The reaction of 2-(2-phenylethynyl)aniline with acetone in presence of [IrCp*Cl2]2 has previously been found to yield a vinyl indole derivative and not the indole expected to form following a hydroamination reaction. Experimental data, including labelling studies, isolation and solid state structure determination of a reaction intermediate together with DFT calculations were used to develop a mechanism for the formation of the vinyl indole. In the mechanism proposed, acetone plays a significant role in several steps of the reaction path, participating in the fragmentation of the dinuclear Ir complex and the formation of the reactive form of the catalyst as well as blocking the formation of the expected hydroamination product by coordination to the Ir catalyst. Coordinated acetone reacts with the aniline to form an imine derivative, which yields the final product following proton transfer promoted by acetone. The proposed mechanism is in good agreement with the experimental data.
先前已发现 2-(2-苯基乙炔基)苯胺与丙酮在 [IrCp*Cl2]2 存在下的反应会产生乙烯基吲哚衍生物,而不是预期在加氢胺化反应后形成的吲哚。实验数据,包括标记研究、反应中间体的分离和固态结构测定以及DFT计算,被用来开发乙烯基吲哚的形成机制。在所提出的机理中,丙酮在反应路径的几个步骤中发挥着重要作用,参与双核Ir配合物的裂解和催化剂反应形式的形成,并通过配位阻止预期加氢胺化产物的形成到 Ir 催化剂。配位丙酮与苯胺反应形成亚胺衍生物,在丙酮促进的质子转移后产生最终产物。所提出的机制与实验数据非常吻合。
Application of UV-Vis spectroscopy to high throughput screening of hydroamination catalysts
作者:Danielle F. Kennedy、Barbara A. Messerle、Sarah L. Rumble
DOI:10.1039/b820357c
日期:——
Potential catalysts for the hydroamination of 2-(2-phenylethynyl)aniline 2 which have been identified through high throughputscreening methods were investigated. Two complexes were shown to be highly active hydroamination catalysts in acetone: the in situ combinations of [Rh(CO)2Cl]2–mesBIAN–NaBF4 (mesBIAN = bis(2,4,6-trimethylphenylimino)acenapthene) and [Ir(COD)Cl]2–NaBF4 (COD = 1,5-cyclooctadiene)