Introducing a mixed-valent dirhodium(II,III) catalyst with increased stability in C-H amination.

A new mixed-valent Rh(2)(II,III) dimer, [Rh(2)(espn)(2)Cl] (espn(2-) = α,α,α',α'-tetramethyl-1,3-benzenedipropanamidate), is reported. This compound readily dissociates Cl(-) at low concentrations in solution to form the active [Rh(2)(espn)(2)](+) catalyst, which performs intramolecular C-H amination with TONs > 1400. This work expands the scope of Rh(2)(II,III) dimers to nitrenoid chemistry.