Expanding the substrate scope for C-H amination reactions: oxidative cyclization of urea and guanidine derivatives.
[reaction: see text] Oxidative C-H amination of N-trichloroethoxysulfonyl-protected ureas and guanidines is demonstrated to proceed in high yield for tertiary and benzylic-derived substrates. The success of these reactions is predicated on the choice of the electron-withdrawn 2,2,2-trichloroethoxysulfonyl (Tces) protecting group, the commercial catalyst Rh(2)(esp)(2) (1-2 mol %), and toluene as solvent. The frequency with which the heterocyclic imidazolidin-2-ones and 2-aminoimidazolines appear as structural elements in both natural products and therapeutically designed molecules confers these methods with a large number of potential applications.
Kim
Mihyong
M
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Mulcahy
John V
JV
Espino
Christine G
CG
Du Bois
J
J
D000586:Amination; D002384:Catalysis; D003500:Cyclization; D006146:Guanidines / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry*
D006146:Guanidines; D014508:Urea