Mn(III)-Catalyzed Synthesis of Pyrroles from Vinyl Azides and 1,3-Dicarbonyl Compounds Yi-Feng Wang, Kah Kah Toh, Shunsuke Chiba,* and Koichi Narasaka* DiVision of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological UniVersity, Singapore 637371, Singapore shunsuke@ntu.edu.sg; narasaka@ntu.edu.sg Received September 10, 2008 ABSTRACT Polysubstituted N-H pyrroles with a wide variety of substituents were prepared from vinyl azides and 1,3-dicarbonyl compounds by using Mn(III) complexes as catalysts. Pyrroles are one of the most prevalent heterocyclic com- pounds, being present as the basic cores in many natural products, 1 potent pharmaceutical compounds, 2 and various kinds of functional materials. 3 Despite numerous diverse approaches toward the synthesis of pyrroles developed so far, 4 it is still challenging to prepare polysubstituted pyrroles with various substituents from readily available building blocks. Recently, we have reported a synthetic method to prepare pyrroles by Cu(II)-catalyzed reactions of vinyl azides and ethyl acetoacetate. 5 In this reaction, however, introduc- tion of an alkoxycarbonyl group at the R-position of vinyl azides is indispensable to realize high yield. It is probably because this transformation proceeds by 1,4-anionic addition of ethyl acetoacetate to vinyl azides. 6 Furthermore, 1,3- diketones such as acetylacetone could not be utilized for this Cu(II)-catalyzed method. Based on these backgrounds, we (1) For recent reviews, see: (a) Walsh, C. T.; Garneau-Tsodikova, S.; Howard-Jones, A. R. Nat. Prod. Rep. 2006, 23, 517. (b) Fu¨ rstner, A. Angew. Chem., Int. Ed. 2003, 42, 3582. (c) Hoffmann, H.; Lindel, T. Synthesis 2003, 1753. (2) (a) Hall, A.; Atkinson, S.; Brown, S. H.; Chessell, I. P.; Chowdhury, A.; Giblin, G. M. P.; Goldsmith, P.; Healy, M. P.; Jandu, K. S.; Johnson, M. R.; Michel, A. D.; Naylor, A.; Sweeting, J. A. Bioorg. Med. Chem. Lett. 2007, 17, 1200. (b) Bellina, F.; Rossi, R. Tetrahedron 2006, 62, 7213. (c) Micheli, F.; Di Fabio, R.; Benedetti, R.; Capelli, A. M.; Cavallini, P.; Cavanni, P.; Davalli, S.; Donati, D.; Feriani, A.; Gehanne, S.; Hamdan, M.; Maffeis, M.; Sabbatini, F. M.; Tranquillini, M. E.; Viziano, M. V. A. Farmaco 2004, 59, 175. (d) Huffman, J. W. Curr. Med. Chem. 1999, 6, 705. (e) Roth, B. D.; Blankley, C. J.; Chucholowski, A. W.; Ferguson, E.; Hoefle, M. L.; Ortwine, D. F.; Newton, R. S.; Sekerke, C. S.; Sliskovic, D. R.; Stratton, C. D.; Wilson, M. W. J. Med. Chem. 1991, 34, 357. (3) (a) Plitt, P.; Gross, D. E.; Lynch, V. M.; Sessler, J. L. Chem. Eur. J. 2007, 13, 1374. (b) Zhao, W.; Carreira, E. M. Chem. Eur. J. 2006, 12, 7254. (c) Gale, P. A. Acc. Chem. Res. 2006, 39, 465. (d) Nadeau, J. M.; Swager, T. M. Tetrahedron 2004, 60, 7141. (e) Sessler, J. L.; Camiolo, S.; Gale, P. A. Coord. Chem. ReV. 2003, 240, 17. (f) Yoon, D. W.; Hwang, H.; Lee, C. H. Angew. Chem., Int. Ed. 2002, 41, 1757. (g) Seidel, D.; Lynch, V.; Sessler, J. L. Angew. Chem., Int. Ed. 2002, 41, 1422. (h) Miyaji, H.; Sato, W.; Sessler, J. L. Angew. Chem., Int. Ed. 2000, 39, 1777. (i) Depraetere, S.; Smet, M.; Dehaen, W. Angew. Chem., Int. Ed. 1999, 38, 3359. (4) For recent reports on the synthesis of polysubstituted pyrroles, see: (a) Cacchi, S.; Fabrizi, G.; Filisti, E. Org. Lett. 2008, 10, 2629. (b) St. Cyr, D. J.; Arndtsen, B. A. J. Am. Chem. Soc. 2007, 129, 12366. (c) Cadierno, V.; Gimeno, J.; Nebra, N. Chem. Eur. J. 2007, 13, 9973. (d) Su, S.; Porco, J. A., Jr. J. Am. Chem. Soc. 2007, 129, 7744. (e) Dong, H.; Shen, M.; Redford, J. E.; Stokes, B. J.; Pumphrey, A. L.; Driver, T. G. Org. Lett. 2007, 9, 5191. (f) Shindo, M.; Yoshimura, Y.; Hayashi, M.; Soejima, H.; Yoshikawa, T.; Matsumoto, K.; Shishido, K. Org. Lett. 2007, 9, 1963. (g) Rodrı´guez Rivero, M.; Buchwald, S. L. Org. Lett. 2007, 9, 973. (h) St. Cyr, D. J.; Martin, N.; Arndtsen, B. A. Org. Lett. 2007, 9, 449. (i) Martı´n, R.; Rodrı´guez Rivero, M.; Buchwald, S. L Angew. Chem., Int. Ed. 2006, 45, 7079. (j) Crawley, M. L.; Goljer, I.; Jenkins, D. J.; Mehlmann, J. F.; Nogle, L.; Dooley, R.; Mahaney, P. E. Org. Lett. 2006, 8, 5837. (k) Binder, J. T.; Kirsch, S. F. Org. Lett. 2006, 8, 2151. (l) Gorin, D. J.; Davis, N. R.; Toste, F. D. J. Am. Chem. Soc. 2005, 127, 11260. (m) Bharadwaj, A. R.; Scheidt, K. A. Org. Lett. 2004, 6, 2465. (n) Siriwardana, A. I.; Kathriar- achchi, K. K. A. D. S.; Nakamura, I.; Gridnev, I. D.; Yamamoto, Y. J. Am. Chem. Soc. 2004, 126, 13898. (o) Dhawan, R.; Arndtsen, B. A. J. Am. Chem. Soc. 2004, 126, 468. (p) Kel’in, A. V.; Sromek, A. W.; Gevorgyan, V. J. Am. Chem. Soc. 2001, 123, 2074. (q) Boger, D. L.; Boyce, C. W.; Labroli, M. A.; Sehon, C. A.; Jin, Q. J. Am. Chem. Soc. 1999, 121, 54. (5) Chiba, S.; Wang, Y.-F.; Lapointe, G.; Narasaka, K. Org. Lett. 2008, 10, 313. ORGANIC LETTERS 2008 Vol. 10, No. 21 5019-5022 10.1021/ol802120u CCC: $40.75  2008 American Chemical Society Published on Web 10/09/2008