ORGANIC
LETTERS
2009
Vol. 11, No. 6
1425-1428
Transition-Metal-Free Intermolecular
Amination of sp3 C-H Bonds with
Sulfonamides
Renhua Fan,* Weixun Li, Dongming Pu, and Li Zhang
Department of Chemistry, Fudan UniVersity, 220 Handan Road, Shanghai, 200433,
China
Received January 16, 2009
ABSTRACT
An efficient transition-metal-free intermolecular benzylic amidation with sulfonamides is described. Various valuable nitrogen-containing
compounds, including amines, ꢀ-chloro amine, amino alcohol, r-, ꢀ-amino ester, and N-sulfonyl imine, are generated from the preferential
N-functionalization of saturated benzylic C-H bonds. The potential of this reaction system also lies in the fact it can be developed into an
environmentally friendly intermolecular amidation process.
The selectively direct N-functionalization of saturated
hydrocarbons, which provides an appealing way for the
synthesis of valuable nitrogen-containing compounds,
represents one of the formidable challenges in chemis-
try.1,2 Since the seminal work by Breslow and co-workers,3
transition-metal-catalyzed nitrene insertion into C-H bonds
has been well-developed and widely used in organic syn-
thesis.1,2 In these elegant processes, ligand-bounded
transition-metal complexes of rhodium,4 ruthenium,5
manganese,5a,b,6 silver,7 copper,8 palladium,9 cobalt,10 and
iron11 as catalysts are essential to the C-H amination
reactions. The wide distribution of amines in natural products
along with their critical industrial application, however,
causes intermolecular amination to remain a challenge for
organic chemists. On the other hand, soaring environmental
awareness demands “green” chemical procedures since the
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10.1021/ol900090f CCC: $40.75
Published on Web 02/17/2009
2009 American Chemical Society