Chemodivergent Nickel(0)-Catalyzed Arene C–F Activation with Alkynes: Unprecedented C–F/C–H Double Insertion

Abstract

Nickel-catalyzed C-F activations enabled chemo-divergent CC formation with alkynes by chelation assistance. The judicious choice of the alkynes electronic properties allowed the selective synthesis of double-insertion aromatic homologation or alkyne mono-annulation products by C-F/C-H activation. Based on the unambiguous crystallographic characterization of an unprecedented 9-membered nickelocyclic intermediate and extensive DFT studies, a plausible mechanistic rationale was established for the selective C-F activation and the chemodivergent catalysis.

Nickel‐Catalyzed Carboxylation of Aryl C−F Bonds with CO2

“…On the basis of our experimental results and previous reports, [11,12,21,27] a mechanistic proposal via Ni(0)−Ni(II)−Ni(I) catalytic cycle is depicted in Scheme 6. Firstly, NiI 2 is reduced by Mn to generate a catalytically active Ni(0) species.…”

“…The main issue of this transformation is the high selectivity of the oxidative addition step toward CÀ F activation over CÀ H activation. The DFT study about this step by Ackermann's group [11] and our experimental results reveal that Li + played a remarkable role, which came from base LiO t Bu and additive LiCl. Firstly, it facilitates the CÀ F oxidative addition to generate a fluorideÀ Ni(II) species, which is clearly exergonic than to form a strongly endergonic hydride-Ni(II) species in this procedure.…”

Recent Advances in Transition‐metal‐catalyzed C−C Bond Formation via C(sp2)−F Bond Cleavage

“…In 2019, Ribas and Ackermann's group reported the nickelcatalyzed chemodivergent annulation reaction via CÀ F bond activation. [17] The selective CÀ F/NÀ H or CÀ F/CÀ H bond activation depended on the electronic properties of the alkynes and provided alkyne monoannulation or aromatic homologation products, respectively. The proposed reaction mechanism was evidenced by the observation of 9-membered nickelacyclic intermediates and extensive DFT studies (Scheme 10).…”

“…In 2019, Ribas and Ackermann's group reported the nickel‐catalyzed chemodivergent annulation reaction via C−F bond activation [17] . The selective C−F/N−H or C−F/C−H bond activation depended on the electronic properties of the alkynes and provided alkyne monoannulation or aromatic homologation products, respectively.…”

Nickel‐Catalyzed Suzuki‐Miyaura Cross‐Coupling Involving C−O Bond Activation

“…n1 n1 A similar nitrogen‐based Ni(0) ate complex was proposed [20] . An alkoxy anion‐substituted Ni(0) ate complex, which facilitates the rate determining C−O activation step, was proposed as a key catalytic species in the Ni‐catalyzed hydrogenolysis of aryl ethers [21] …”