On the Reactivity of a NHC Nickel Bis‐Boryl Complex: Reductive Elimination and Formation of Mono‐Boryl Complexes.

The synthesis of the first terminal mono‐boryl complexes of nickel, which are not stabilized by a pincer ligand, is reported. The reaction of the nickel bis‐boryl complex cis‐[Ni(iPr2ImMe)2(Bcat)2] 1 (cat=1,2‐O2C6H4) with the small donor ligand PMe3 led to a complete ligand exchange at nickel with reductive elimination of B2cat2 and formation of the bis‐NHC adduct [B2cat2 ⋅ (iPr2ImMe)2] 3 and [Ni(PMe3)4] 2 as the metal‐containing species. Electrophilic attack of MeI on complex 1 or ligand dismutation of 1 with trans‐[Ni(iPr2ImMe)2Br2] led to loss of only one boryl ligand of 1 and afforded the nickel mono‐boryl complexes trans‐[Ni(iPr2ImMe)2(Bcat)Br] 4 a and trans‐[Ni(iPr2ImMe)2(Bcat)I] 4 b. [ABSTRACT FROM AUTHOR]