Ketones, reaction with indole Grignard

The diketoindoles 777 were prepared in three steps starting from indol-3-ylacetic acid (680) and 5-chloro indol-3-ylacetic acid (774) in 75% and 66% overall yield, respectively. The indole acids 680 and 774 were converted into Weinreb amides 775, followed by reaction with ethyl Grignard reagent to afford the corresponding indol-3-yl ketones 776. In order to introduce the second carbonyl moiety, the 3-substituted... 

Indolyl A-Grignards, "" or even better their zinc analogues, undergo reaction predominantly at C-3 with a variety of carbon electrophiles such as aldehydes, ketones and acid halides, or reactive halo-hetero-cycles. Including aluminium chloride in the zinc reactions produces high yields of 3-acyl-indoles. The copper-catalysed reactions of indolyl-A-Grignards with A-t-butoxycarbonyl-aziridines also proceed well at C-3. ... 

Conversion of isatins into oxindoles can be achieved by catalytic reduction in acid, or by the Wolff-Kischner process.3-Substituted indoles result from Grignard addition at the ketone carbonyl, followed by lithium aluminium hydride reduction of the residual amide, then dehydration. The reaction of isatin with triphenylphosphine provides an easy synthesis of 3-(triphenylphosphorylidene)oxindole, a Wittig reagent. ... 

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