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Synfacts 2007(1): 0019-0019  
DOI: 10.1055/s-2006-955745
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Pyrroles and Pyrazoles by a C-N Coupling-Hydroamination Sequence

Contributor(s): Victor Snieckus, Todd Macklin
R. Martín, M. R. Rivero, S. L. Buchwald*
Massachusetts Institute of Technology, Cambridge, USA
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Publication History

Publication Date:
15 December 2006 (online)

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Significance

Reported is an elegant Cu-catalyzed amidation/hydroamidation of haloenynes with tert-butyl carbamate or bis(Boc)hydrazine affording, after TFA-induced deprotection/tauto­merization, highly substituted pyrroles and pyrazoles in good to excellent yields. N,N′-Dimethylethylenediamine (20 mol%) was found to be the most effective ligand for the conversion. Intermediary amidation products were isolated, thus validating the proposed sequence of C-N coupling followed by hydroamidation.