Wang A, Venditto NJ, Darcy JW, Emmert MH. Nondirected, Cu-Catalyzed sp
3 C-H Aminations with Hydroxylamine-Based Amination Reagents: Catalytic and Mechanistic Studies.
Organometallics 2017;
36:1259-1268. [PMID:
31223182 DOI:
10.1021/acs.organomet.7b00003]
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Abstract
This work demonstrates the use of hydroxylamine-based amination reagents RSO2NH-OAc for the nondirected, Cu-catalyzed amination of benzylic C-H bonds. The amination reagents can be prepared on a gram scale, are benchtop stable, and provide benzylic C-H amination products with up to 86% yield. Mechanistic studies of the established reactivity with toluene as substrate reveal a ligand-promoted, Cu-catalyzed mechanism proceeding through Ph-CH2(NTsOAc) as a major intermediate. Stoichiometric reactivity of Ph-CH2(NTsOAc) to produce Ph-CH2-NHTs suggests a two-cycle, radical pathway for C-H amination, in which the decomposition of the employed diimine ligands plays an important role.
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