Sm. Au et al., Amidation of unfunctionalized hydrocarbons catalyzed by ruthenium cyclic amine or bipyridine complexes, J ORG CHEM, 65(23), 2000, pp. 7858-7864
Selective amidation of simple hydrocarbons with pre-isolated and in-situ fo
rmed iminoiodanes catalyzed by ruthenium complexes [Ru-III(Me(3)tacn)(CF3CO
2)(3).H2O] (2b, Me(3)tacn = N,N,N"-trimethyl-1,4,7-triazacyclononane) and c
is-[Ru-II(6,6'-Cl(2)bpy)(2)Cl-2] (3, 6,6'-Cl(2)bpy = 6,6'-dichloro-2,2'-bip
yridine) was investigated. With PhI=NTs as nitrogen source, both catalysts
efficiently promote the amidation of adamantane, cyclohexene, ethylbenzene,
cumene, indan, tetralin, and diphenylmethane to afford N-substituted sulfo
namides in 80-93% yields with high selectivity. Competitive amidations of p
arasubstituted ethylbenzenes and kinetic isotope effect for the amidation o
f cyclohexene/cyclohexene-d(10) suggest that the amidation processes probab
ly proceed via the hydrogen abstraction by a reactive Ru=NTs species to for
m a carboradical intermediate. The amidation with PhI(OAc)(2)/TsNH2 gave re
sults comparable to those obtained with PhI=NTs. Extension of the "PhI(OAc)
(2)/TsNH2 + catalyst 2b or 3" protocol to MeSO2NH2 and PhCONH2 with ethylbe
nzene as substrate produced the corresponding N-substituted amides in up to
89% yield.