5-METHYL-2-PHENYLINDOLE synthesis

Yield: 89%

Reaction Conditions:

with norborn-2-ene;dichloro bis(acetonitrile) palladium(II);potassium carbonate in N,N-dimethyl acetamide;water at 70;regioselective reaction;

Steps:

2. General procedure for 2-arylation of free (N-H) indoles
General procedure: A high pressure tube equipped with a magnetic stirring bar was charged with indole substrate (0.2mmol, 1 equiv.), norbornene (0.4mmol, 2 equiv.), the base (0.4mmol, 2 equiv. K₂CO₃ or 2 equiv. KHCO₃, as indicated),, and PdCl₂(MeCN)₂ (0.02mmol, 10 mol %). A solution of water (0.5 M) in DMA (1mL) was added via syringe, and then the aryl iodide (0.4mmol, 2 equiv.) was added via syringe. The reaction mixture was then placed in a preheated oil bath at 70 °C (or 90 °C, as indicated). Vigorous stirring was applied. The reaction was monitored by TLC. Upon completion, the reaction mixture was cooled to room temperature, diluted with EtOAc, and filtered. The filtrate was extracted with H₂O (3 times) and brine, the organic phase was concentrated in vacuum to remove the solvent. The residue was directly submitted to flash column chromatography to afford the 2-arylindole product. The spectral data of the products were in accordance with those reported in the literature¹.

References:

Gao, Yadong;Zhu, Wangying;Yin, Long;Dong, Bo;Fu, Jingjing;Ye, Zhiwen;Xue, Fengtian;Jiang, Chao [Tetrahedron Letters,2017,vol. 58,# 23,p. 2213 - 2216] Location in patent:supporting information