A Route to 2-Vinylindoles

2- and 3-Vinylindoles are valuable precursors to many carbazoles and to indole alkaloids. The 

3- substituted compounds are readily accessible, but the 2-vinyl derivatives have only recently become easily available as a result of a clever synthesis developed by Indian workers. This is illustrated by the conversion of V-(allenylmethyl)-iV-methylaniline 1 into 2-ethenyl-N-methylindole 2 in 80% yield by treatment with MMPP in aqueous methanol at room temperature. 

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