Thermal and Microwave‐Assisted Conjugate Additions of Indole on Electron‐Deficient Nitro‐Olefins.

Abstract

Indole derivatives R 0140Thermal and Microwave-Assisted Conjugate Additions of Indole on Electron--Deficient Nitro-Olefins. -The microwave-assisted conjugate addition of indole (I) to electron-deficient nitro-olefins (II) leads to significantly higher yields and proceeds much faster compared to classical methods such as heating in a sealed tube or via Grignard reaction. -(KUSURKAR*, R. S.; ALKOBATI, N. A. H.; GOKULE, A. S.; CHAUDHARI, P. M.; WAGHCHAURE, P. B.; Synth. Commun. 36 (2006) 7-9, 1075-1081; Dep. Chem., Univ. Pune, Pune 411 007, India; Eng.) -H. Haber 35-111

An Efficient Method for the N-Bromosuccinimide Catalyzed Synthesis of Indolyl-Nitroalkanes

“…The solvent was removed under reduced pressure and the crude residue was purified by flash chromatography on silica gel to afford pure product. The references of the known compounds are: 2a [ 14 , 15 , 17 , 19 ], 2b [ 36 ], 2c [ 15 , 22 ], 2d [ 13 , 15 , 17 ], 2e [ 36 ], 2f [ 36 ], 2g [ 22 ], 2j [ 15 , 22 ], 2k [ 15 , 36 ], cis- 2n [ 14 ], trans- 2n [ 14 ], 4a [ 15 , 17 , 19 ], 4b [ 15 , 17 ], 4c [ 12 , 36 ], 4d [ 15 ], 4e [ 14 , 17 ], 4f [ 14 ], 4g [ 17 , 19 ], 4k [ 15 , 35 ], 4l [ 45 ], 5 [ 46 ].…”

“…This is due to the fact that nitroalkenes are very good Michael acceptors and further the Michael adduct of the nitroalkenes are amenable to transformation into a wide range of different functionalized species. Similarly, Friedel-Crafts alkylation of indoles with nitroolefins in the presence of acidic catalysts is well documented in the literature [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Neverthless, most of the procedures reported suffer from several shortcomings such as the use of hazardous catalysts, tedious workup procedures and difficulties in product isolation.…”