Synfacts 2007(6): 0589-0589  
DOI: 10.1055/s-2007-968573
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Rhodium-Catalyzed Intramolecular Hetero-Pauson-Khand Reaction

Contributor(s): Victor Snieckus, Heiko Scharl
T. Saito*, K. Sugizaki, T. Otani, T. Suyama
Tokyo University of Science, Japan
Further Information

Publication History

Publication Date:
22 May 2007 (online)

Significance

Alkyne carbodiimides, readily available through an aza-Wittig reaction of the corresponding iminophosphoranes and isocyanates (T. Saito, M. Shiotani, T. Otani, S. Hasaba Heterocycles 2003, 60, 1045-1048), are shown to undergo rhodium-catalyzed Pauson-Khand reactions to afford pyrrolo[2,3-b]indol-2-ones and pyrrolo[2,3-b]pyrrolin-2-ones derivatives in low to good yields. During the development of this chemistry, several catalytic systems and additives were investigated and the [RhCl(cod)]2 (5 mol%)-dppp (11 mol%) system was found to give the optimal results. The scope of this interesting reaction has been insufficiently tested.