Enantioselective C-H Amination Catalyzed by Nickel Iminyl Complexes Supported by Anionic Bisoxazoline (BOX) Ligands.

ABSTRACT: The trityl-substituted bisoxazoline (^TrHBOX) was prepared as a chiral analogue to a previously reported nickel dipyrrin system capable of ring-closing amination catalysis. Ligand metalation with divalent NiI₂(py)₄ followed by potassium graphite reduction afforded the monovalent (^TrHBOX)Ni(py) (4). Slow addition of 1.4 equiv of a benzene solution of 1-adamantylazide to 4 generated the tetrazido (^TrHBOX)Ni(κ²-N₄Ad₂) (5) and terminal iminyl adduct (^TrHBOX)Ni(NAd) (6). Investigation of 6 via single-crystal X-ray crystallography, NMR and EPR spectroscopies, and computations revealed a Ni(II)-iminyl radical formulation, similar to its dipyrrinato congener. Complex

SUBMITTER: Dong Y 

PROVIDER: S-EPMC9375549 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature