Bis(imidazolidine)-Derived NCN Nickel-Pincer-Catalyzed Asymmetric Reactions

A bis(imidazolidine)-derived NCN nickel-pincer complex (<i>t</i>Bu-PhBidine-Ni-OTf: <b>NCN-Ni-OTf</b>) was synthesized by the oxidative addition of imidazolidine-containing aryl triflate to Ni(cod)₂ in MeCN. <b>NCN-Ni-OTf</b> exhibited asymmetric induction in three reactions. In the Friedel-Crafts reaction of indoles with <i>N</i>-Boc imines, 3-indolylmethanamine products were obtained in 79% yield with 99% ee. In a conjugate addition reaction of malononitrile to nitroalkenes, products were obtained in 95% yield with 75% ee. In iodolactonization, the pincer-Ni complex showed catalytic activity superior to that of <i>t</i>Bu-PhBidine-Pd-OTf.