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The dinuclear b-diketiminato NiIItert-butoxide {[Me3NN]Ni}2(μ-OtBu)2 (2), synthesized from [Me3NN]Ni(2,4-lutidine) (1) and di-tert-butylperoxide, is a versatile precursor for the synthesis of a series of NiIIcomplexes [Me3NN]Ni-FG to illustrate C-C, C-N, and C-O bond formation at NiII via radicals. {[Me3NN]Ni}2(μ-OtBu)2 reacts with nitromethane, alkyl and aryl amines, acetophenone, benzamide, ammonia and phenols to deliver corresponding mono- or dinuclear [Me3NN]Ni-FG species (FG = O2NCH2, R-NH, ArNH, PhC(O)NH, PhC(O)CH2, NH2and OAr). Many of these NiII complexes are capable of capturing the benzylic radical PhCH(•)CH3 to deliver corresponding PhCH(FG)CH3 products featuring C-C, C-N or C-O bonds. DFT studies shed light on the mechanism of these transformations and suggest two competing pathways that depend on the nature of the functional groups. These radical capture reactions at [NiII]-FG complexes outline key C-C, C-N, and C-O bond forming steps and suggest new families of nickel radical relay catalysts.

The synthesis and utility of three benzoxaborole protecting groups are reported. These protecting groups improve organic solubility and allow otherwise incompatible reactions (oxidations, substitutions, and mild reductions) to be achieved in the presence of the benzoxaborole moiety. 3-( N, N-Dimethylamino)-1-propanol was determined to be useful in one-step sequences and is readily cleaved upon workup. Two other groups, N-methylsalicylidenimine and 2-[1-(methylimino)ethyl]phenol, are suitable for multistep syntheses. Deprotection with mild aqueous acid allows for chromatography-free isolation of the benzoxaborole in high yields.