NHC-stabilized gold(I) complexes: Suitable catalysts for 6-exo-dig heterocyclization of 1-(o-Ethynylaryl)ureas

Organic Letters

Volumn 12, Issue 9, 2010, Pages 1900-1903

  Gimeno, Ana ^a   Medio Simón, Mercedes ^a   De Arellano, Carmen Ramírez ^a   Asensio, Gregorio ^a   Cuenca, Ana B ^a  

^a UNIVERSITY OF VALENCIA   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 77951820937     PISSN: 15237060     EISSN: 15237052     Source Type: Journal    
DOI: 10.1021/ol100595s     Document Type: Article

References (52)

1. For some selected reviews in gold catalysis, see
2. Li, Z.; Brouwer, C.; He, C. Chem. Rev. 2008, 108, 3239
3. Gorin, D. J.; Sherry, B. D.; Toste, F. D. Chem. Rev. 2008, 108, 3351
4. Arcadi, A. Chem. Rev. 2008, 108, 3266
5. Hashmi, A. S. K. Chem. Rev. 2007, 107, 3180
6. Hashmi, A. S. K.; Rudolph, M. Chem. Soc. Rev. 2008, 37, 1776
7. For selected examples about gold-catalyzed hydroamination reactions, see
8. Widenhoefer, R. A.; Han, X. Eur. J. Org. Chem. 2006, 4555
9. Bender, C. F.; Widenhoefer, R. A. Org. Lett. 2006, 8, 5303
10. Zhang, Y.; Donahue, J. P.; Li, C. J. Org. Lett. 2007, 9, 627
11. Lalonde, R. L.; Sherry, B. D.; Kang, E. J.; Toste, F. D. J. Am. Chem. Soc. 2007, 129, 2452
12. Liu, X. Y.; Ding, P.; Huang, J. S.; Che, C. M. Org. Lett. 2007, 9, 2645
13. Nishina, N.; Yamamoto, Y. Synlett 2007, 11, 1767
14. Zhang, Z.; Bender, C. F.; Widenhoefer, R. A. Org. Lett. 2007, 9, 2887
15. Zhang, Z.; Bender, C. F.; Widenhoefer, R. A. J. Am. Chem. Soc. 2007, 129, 14148
16. Giner, X.; Nájera, C. Org. Lett. 2008, 10, 2919
17. Kinder, R. E.; Zhang, Z.; Widenhoefer, R. A. Org. Lett. 2008, 10, 3157
18. Zhang, Z.; Lee, S.; Widenhoefer, R. A. J. Am. Chem. Soc. 2009, 131, 5372
19. Zeng, X.; Soleilhavoup, M.; Bertrand, G. Org. Lett. 2009, 11, 3166
20. Zeng, X.; Frey, G. D.; Kinjo, R.; Donnadieu, B.; Bertrand, G. J. Am. Chem. Soc. 2009, 131, 8690
21. Zeng, X.; Frey, G. D.; Kousar, S.; Bertrand, G. Chem.- Eur. J. 2009, 15, 3056
22. Han, Z.-Y.; Xiao, H.; Chen, X.-H.; Gong, L.-Z. J. Am. Chem. Soc. 2009, 131, 9182
23. For general recent reviews about hydroamination reactions, see
24. Muller, T. E.; Hultzsch, K. C.; Yus, M.; Foubelo, F. M.; Tada, M. Chem. Rev. 2008, 108, 3795
25. Severin, R.; Doye, S. Chem. Soc. Rev. 2007, 36, 1407
26. Arcadi, A.; Bianchi, G.; Marinelli, F. Synthesis 2004, 4, 610
27. Alfonsi, M.; Arcadi, A.; Aschi, M.; Bianchi, G.; Marinelli, F. J. Org. Chem. 2005, 70, 2265
28. Arcadi, A.; Alfonsi, M.; Bianchi, G.; DAnniballe, G.; Marinelli, F. Adv. Synth. Catal. 2006, 348, 331
29. Ambrogio, I.; Arcadi, A.; Cacchi, S.; Fabrizi, G.; Marinelli, F. Synlett 2007, 11, 1775
30. Nakamura, I.; Yamagishi, U.; Song, D.; Konta, S.; Yamamoto, Y. Angew. Chem., Int. Ed. 2007, 46, 2284
31. Zhang, Y.; Donahue, J.; Li, C. Org. Lett. 2007, 9, 627
32. Nakamura, I.; Sato, Y.; Konta, S.; Terada, M. Tetrahedron Lett. 2009, 50, 2075
33. Ye, D.; Wang, J.; Zhang, X.; Zhou, Y.; Ding, X.; Feng, E.; Sun, H.; Liu, G.; Jiang, H.; Liu, H. Green Chem. 2009, 11, 1201
34. For gold-catalyzed reactions where a plausible competition between two nitrogen nucleophiles is present, see
35. Kadzimirsz, D.; Hildebrandt, D.; Merz, K.; Dyker, G. Chem. Commun. 2006, 661
36. Bender, C. F.; Widenhoefer, R. A. Org. Lett. 2006, 8, 5303
37. See ref 4.
38. Iglesias, A.; Muñiz, K. Chem.- Eur. J. 2009, 15, 10563
39. To the best of our knowledge, only two examples for the synthesis of the quinazolin-2-one core from 1-(o -alkynylaryl)ureas have been reported.
40. II-catalyzed: Costa, M.; Della Ca, N.; Gabriele, B.; Massera, C.; Salerno, G.; Soliani, M. J. Org. Chem. 2004, 69, 2469
41. TfOH-mediated: Wang, H.; Liu, L.; Wang, Y.; Peng, C.; Zhang, J.; Zhu, Q. Tetrahedron Lett. 2009, 50, 6841
42. Molina, P.; Conesa, C.; Alías, A.; Arques, A.; Velasco, M.; Llamas-Saiz, A. L.; Foces-Foces, C. Tetrahedron 1993, 49, 7599
43. Brack, A. Lieb. Ann. Chem. 1969, 730, 166
44. Benzooxazepin-2-amines arising from the nucleophilic attack of ureas 1 through their tautomeric carbamimidic forms could be also envisioned.
45. -3.
46. Given the well-documented tendency of diarylureas to behave as polymorphic structures because of their hydrogen-bonding patterns, we carried out the reaction under different concentrations (0.05 and 0.2 M in DMF). We found, no appreciable change in the conversion as a function of the concentration.
47. Dannecker, W.; Kopf, J.; Rust, H. Cryst. Struct. Commun. 1979, 8, 429
48. Etter, M.; Panuto, T. J. Am. Chem. Soc. 1988, 110, 5896
49. 6 and 5% copper(II) salts, but in every case, the starting material remained unaltered.
50. Frémont, P.; Scott, N. M.; Stevens, E. D.; Nolan, S. P. Organometallics 2001, 24, 2411-2418
51. The structure of indole 3b was established by single-crystal X-ray diffraction; see Supporting Information.
52. Ureas 1a-1c, 1e, 1h-1j, 1l, 1m, 1o, and 1q were prepared by the reaction of o -alkynylanilines and isocyanates and used without further purification. The syntheses of 1f, 1g, 1n, 1p, and 1r were run over 12 h, and 1.5 equiv of the corresponding isocyanate was needed to achieve complete conversion of the 2-ethynylaniline derivative. To avoid secondary reactions, these ureas were purified by column chromatography.