Nickel-Catalyzed trans-Carboamination across Internal Alkynes to Access Multifunctionalized Indoles
Shrikant D Tambe1, Naeem Iqbal1, Eun Jin Cho1
1Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
Abstract:
A Ni-catalyzed reaction was developed for the synthesis of multifunctionalized indoles. The reaction proceeded through oxidative cyclization of the Ni(0)/P^N complex with an enyne system, 2-alkynyl anilinoacrylate, to provide a nickelacycle intermediate. The trans-carboamination around the internal alkyne was achieved by syn/anti-rotation of the Ni-carbenoid intermediate formed by C-N bond cleavage of the nickelacycle, and 3-alkenylated indoles were formed by C-N bond-forming reductive elimination. Notably, the synthesized indoles could be successfully transformed to functionalized carbazoles.
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