Oxazole Synthesis from Isocyanides

Abstract

A new synthetic path toward oxazoles starting from isocyanides is presented. This two-step oxazole preparation involves a bromination–cyclization followed by a Suzuki cross-coupling.

Key words

oxazoles - Suzuki - palladium - isocyanides - dihalogenoisocyanides

• References

• For recent reviews, see:

• 1a Dömling A, Ugi I. Angew. Chem. Int. Ed. 2000; 39: 3168
• 1b Bienaymé H, Hulme C, Oddon G, Schmitt P. Chem.–Eur. J. 2000; 6: 3321
• 1c Ugi I, Werner B, Dömling A. Molecules 2003; 8: 53
• 1d Dömling A. Curr. Opin. Chem. Biol. 2002; 6: 306
• 1e Multicomponent Reactions. Zhu J, Bienaymé H. Wiley-VCH; Weinheim: 2005
• 1f Dömling A. Chem. Rev. 2006; 106: 17
• 2a Kamijo S, Yamamoto Y. J. Am. Chem. Soc. 2002; 124: 11940
• 2b Kamijo S, Jin T, Yamamoto Y. Angew. Chem. Int. Ed. 2002; 41: 1780
• 2c Sanchez RS, Zhuravlev FA. J. Am. Chem. Soc. 2007; 129: 5824
• 3a Ito Y, Bando T, Matsuura T, lshikawa M. J. Chem. Soc., Chem. Commun. 1986; 980
• 3b Tobisu M, Imoto S, Ito S, Chatani N. J. Org. Chem. 2010; 75: 4835
• 3c Saluste CG, Whitby RJ, Furber M. Angew. Chem. Int. Ed. 2000; 39: 4156
• 3d Saluste CG, Whitby RJ, Furber M. Tetrahedron Lett. 2001; 42: 6191
• 3e Kishore K, Tetala R, Whitby RJ, Light ME, Hurtshouse MB. Tetrahedron Lett. 2004; 45: 6991
• 3f Saluste CG, Crumpler S, Furberb M, Whitby RJ. Tetrahedron Lett. 2004; 45: 6995
• 3g Jiang H, Liu B, Li Y, Wang A, Huang H. Org. Lett. 2011; 13: 1028
• 3h Vlaar T, Ruijter E, Znabet A, Janssen E, de Kanter FJ. J, Maes BU. W, Orru RV. A. Org. Lett. 2011; 13: 6496
• 4a Ito Y, Inouye M, Yokota H, Murakami M. J. Org. Chem. 1990; 55: 2567
• 4b Ito Y, Inouye M, Murakami M. Tetrahedron Lett. 1988; 29: 5379
• 5 Baeza A, Burgos C, Alvarez-Builla J, Vaquero JJ. Tetrahedron Lett. 2007; 48: 2597
• 6 El Kaïm L, Grimaud L, Pravin P. Org. Lett. 2011; 13: 1261

• The conversion of isocyano esters and amide into imidoyl chlorides followed by cyclization into oxazoles has already been observed during the Nef reaction between isocyanides and acyl chlorides:

• 7a Mossetti R, Pirali T, Tron GC, Zhu J. Org. Lett. 2010; 12: 820
• 7b Huang W.-S, Zhang Y.-X, Yuan C.-Y. Synth. Commun. 1996; 26: 1149
• 8a Gonzalez-Zamora E, Fayol A, Bois-Choussy M, Chiaroni A, Zhu J. Chem. Commun. 2001; 1684
• 8b Sun X, Janvier P, Zhao G, Bienaymé H, Zhu J. Org. Lett. 2001; 3: 877
• 8c Gamez-Montano R, Zhu J. Chem. Commun. 2002; 2448
• 8d Janvier P, Sun X, Bienaymé H, Zhu J. J. Am. Chem. Soc. 2002; 124: 2560
• 8e Lalli C, Bouma MJ, Bonne D, Masson G, Zhu J. Chem. Eur. J. 2011; 17: 880
• 9a Webb MR, Addie MS, Crawforth CM, Dale JW, Franci X, Pizzonero M, Donald C, Taylor RJ. K. Tetrahedron 2008; 64: 4778
• 9b Dakin LA, Langille NF, Panek JS. J. Org. Chem. 2002; 67: 6812
• 9c You S.-L, Kelly JW. J. Org. Chem. 2003; 68: 9506
• 9d For a review on the synthesis of natural occurring oxazoles, see: Yeh VS. C. Tetrahedron 2004; 60: 11995
• 10a Turchi IJ, Dewar MJ. S. Chem. Rev. 1975; 75: 389
• 10b Palmer DC, Taylor EC. Oxazoles: Synthesis, Reactions and Spectroscopy, In Chemistry of Heterocyclic Compounds . Part A and B, Vol. 60. John Wiley and Sons; New York: 2004