Arylketones can be synthesized conveniently by a palladiumcatalyzedaddition of arylboronic acid to nitriles in aqueous triflic acid. This catalytic system was extended to the addition of unprotected indoles to nitriles under a slightly modified condition to produce 3-acyl indoles in good yields.
A Simple, Effective, Green Method for the Regioselective 3-Acylation of Unprotected Indoles
作者:Phuong Tran、Hai Tran、Poul Hansen、Mai Do、Thach Le
DOI:10.3390/molecules201019605
日期:——
A fast and green method is developed for regioselective acylation of indoles in the 3-position without the need for protection of the NH position. The method is based on Friedel-Crafts acylation using acid anhydrides. The method has been optimized, and Y(OTf)3 in catalytic amounts is found to be the best catalyst together with the commercially available ionic liquid [BMI]BF4 (1-butyl-3-methylimidazolium tetrafluoro-borate) as solvent. The reaction is completed in a very short time using monomode microwave irradiation. The catalyst can be reused up to four times without significant loss of activity. A range of substituted indoles are investigated as substrates, and thirteen new compounds have been synthesized.
Brønsted acidic ionic liquid-promoted direct C3-acylation of <i>N</i>-unsubstituted indoles with acid anhydrides under microwave irradiation
作者:Phuong Hoang Tran、Anh-Thanh Duy Nguyen、Hai Truong Nguyen、Thach Ngoc Le
DOI:10.1039/c7ra11362e
日期:——
A green and efficient method for the synthesis of 3-acylindoles using a Brønsted acidic ionic liquid under microwave irradiation has been developed.
使用布朗斯特酸性离子液体在微波辐射下合成3-酰基吲哚的一种绿色高效方法已经开发出来。
An efficient and green method for regio- and chemo-selective Friedel–Crafts acylations using a deep eutectic solvent ([CholineCl][ZnCl<sub>2</sub>]<sub>3</sub>)
作者:Phuong Hoang Tran、Hai Truong Nguyen、Poul Erik Hansen、Thach Ngoc Le
DOI:10.1039/c6ra03551e
日期:——
and ZnCl2, has been used as a dual function catalyst and green solvent for the Friedel–Crafts acylation of aromatic compounds instead of using the moisture-sensitive Lewisacids and volatile organic solvents. The reactions are performed with high yields under microwave irradiation with short reaction times for the synthesis of ketones. Interestingly, indole derivatives are regioselectively acylated in
The formation of acylimino-derivatives of indoles and pyrroles by reactions with nitrilium salts
作者:Stephen C. Eyley、Robert G. Giles、Harry Heaney
DOI:10.1016/s0040-4039(00)98776-8
日期:1985.1
fluoroborates are prepared rapidly by warming trimethyloxonium fluoroborate with a slight excess of the nitrile, subsequent addition of indoles and pyrroles at low temperatures (−50° to −20°) gives iminium salts (and hence ketones) in high yields.