Kumada coupling indoles

Of all the palladium-catalyzed coupling reactions, the Kumada coupling has been applied least often in indole chemistry. However, this Grignard-Pd cross-coupling methodology has been used to couple l-methyl-2-indolylmagnesium bromide with iodobenzene and a-bromovinyltrimethylsilane to form l-methyl-2-phenylindole and l-methyl-2-(l-trimethyl-... 

Kondo employed the Kumada coupling using the Grignard reagents derived from 2- and 3-iodo-l-(phenylsulfonyl)indole to prepare the corresponding phenyl derivatives in 50% yield [92], Widdowson expanded the scope of the Kumada coupling and provided some insight into the mechanism [93],... 

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