Bis(imidazolidine)-Derived\nNCN Nickel-Pincer-Catalyzed\nAsymmetric Reactions

A bis(imidazolidine)-derived NCN\nnickel-pincer complex\n(<i>t</i>Bu-PhBidine-Ni-OTf: <b>NCN-Ni-OTf</b>) was\nsynthesized\nby the oxidative addition of imidazolidine-containing aryl triflate\nto Ni(cod)<sub>2</sub> in MeCN. <b>NCN-Ni-OTf</b> exhibited\nasymmetric induction in three reactions. In the Friedel–Crafts\nreaction of indoles with <i>N</i>-Boc imines, 3-indolylmethanamine\nproducts were obtained in 79% yield with 99% ee. In a conjugate addition\nreaction of malononitrile to nitroalkenes, products were obtained\nin 95% yield with 75% ee. In iodolactonization, the pincer-Ni complex\nshowed catalytic activity superior to that of <i>t</i>Bu-PhBidine-Pd-OTf.