Nickel Meets Aryl Thianthrenium Salts: Ni(I)-Catalyzed Halogenation of Arenes

Abstract

Herein, a regioselective, late-stage two-step arene halogenation method is reported. We propose how unusual Ni(I)/ (III) catalysis is enabled by a combination of aryl thianthrenium and Ni redox properties that is hitherto unachieved with other (pseudo)halides. The catalyst is accessed in situ from inexpensive NiCl 2 •6(H 2 O) and zinc without the need of supporting ligands.

Synthesis of Nickel(I)–Bromide Complexes via Oxidation and Ligand Displacement: Evaluation of Ligand Effects on Speciation and Reactivity

“…Strategies to enable the synthesis of previously unknown Ni I complexes create downstream opportunities for more effective Ni catalysis. Contributions from Morandi and co-workers, who recently reported a phenoxide-bound Ni I precursor, have already led to mechanistic insight and development in Ni-catalyzed methodologies . Further goals for the synthetic organometallic community in this area include the complexation of catalytically relevant ligands to structurally novel Ni I centers, the incorporation of easily derivatized X-type ligands such as halides, and the application of synthetic discoveries to catalytic systems.…”

Regioselective Organocatalyzed Monochlorination of Arenes with Electrophilic Chlorosulfoniums

“…using of N ‐chlorosuccinimide (NCS) and sulfur‐based Lewis bases as catalysts (Scheme 2a). Notably, sulfonium salts have been described as intermediates in aromatics umpolung, allowing the use of nucleophilic chloride (tetrabutyl ammonium chloride TBACl is a common reagent to accomplish this task; see Scheme 2b) [6b] . However, the sulfonium salt must be previously prepared with stoichiometric thianthrene oxide, [9] and then transition metal catalysts or promoters are imperative (Scheme 2b).…”

Organohypervalent heterocycles

“…Moreover, the Ritter group developed an unusual Ni( i )/Ni( iii )-catalyzed regioselective late-stage arene halogenation method (Scheme 19(b)). 248…”