Solvent-free organic syntheses . using supported reagents and microwave irradiation

Abstract

Recent developments in microwave-accelerated solventless organic syntheses are summarised. This expeditious and solvent-free approach involves the exposure of neat reactants to microwave (MW) irradiation in conjunction with the use of supported reagents or catalysts which are primarily of mineral origin. The salient features of these high yield protocols are the enhanced reaction rates, greater selectivity and the experimental ease of manipulation. Among other reagents recently described in the literature on this eco-friendly green approach, the use of recyclable mineral oxides or supported reagents from our laboratory such as Fe(NO₃)₃–clay (clayfen), Cu(NO₃)₂–clay (claycop), NH₄NO₃–clay (clayan), NH₂OH–clay, PhI(OAc)₂–alumina, NaIO₄–silica, CrO₃–alumina, MnO₂–silica, NaBH₄–clay, etc. are highlighted in MW-promoted deprotection, condensation, cyclization, rearrangement, oxidation and reduction reactions including the rapid one-pot assembly of heterocyclic compounds from in situ generated intermediates.

References

1. Using chemical reagents on porous carriers, Akt.-Ges. Fur Chemiewerte, Br. Pat., 1924, 231, 901; Chem. Abstr., 1925, 19, 3571.
2. (a) G. H. Posner, Angew. Chem., Int. Ed. Engl., 1978, 17, 487; (b) A. McKillop and K. W. Young, Synthesis, 1979, 401 and 481.
3. (a) A. Cornelis and P. Laszlo, Synthesis, 1985, 909; (b) P. Laszlo, Preparative Chemistry Using Supported Reagents, Academic Press, Inc., San Diego, 1987; (c) K. Smith, Solid Supports and Catalyst in Organic Synthesis, Ellis Horwood, Chichester, 1992; (d) M. Balogh and P. Laszlo, Organic Chemistry Using Clays, Springer-Verlag, Berlin, 1993; (e) J. H. Clark, Catalysis of Organic Reactions by Supported Inorganic Reagents, VCH Publishers, Inc., NY, 1994; (f) J. H. Clark and D. J. Macquarrie, Chem. Commun., 1998, 853; (g) G. W. Kabalka and R. M. Pagni, Tetrahedron, 1997, 53, 7999.
4. R. Gedye, F. Smith, K. Westaway, H. Ali, L. Baldisera, L. Laberge and J. Rousell, Tetrahedron Lett., 1986, 27, 279.
5. For recent reviews on microwave-assisted chemical reactions see: (a) R. A. Abramovich, Org. Prep. Proc. Int., 1991, 23, 683; (b) A. G. Whittaker and D. M. P. Mingos, J. Microwave Power Electromagnetic Energy, 1994, 29, 195; (c) S. Caddick, Tetrahedron, 1995, 51, 10403; (d) C. R. Strauss and R. W. Trainor, Aust. J. Chem., 1995, 48, 1665; (e) A. K. Bose, B. K. Banik, N. Lavlinskaia, M. Jayaraman and M. S. Manhas, CHEMTECH, 1997, 27, 18; (f) R. S. Varma, Clean Products and Processes, 1999, in press.
6. R. J. Giguere, A. M. Namen, B. O. Lopez, A. Arepally, D. E. Ramos, G. Majetich and J. Defrauw, Tetrahedron Lett., 1987, 28, 6553.
7. R. S. Varma, in, Microwaves: Theory and Application in Material Processing IV, ed. D. E. Clark, W. H. Sutton and D. A. Lewis, American Ceramic Society, Westerville, OH, 1997, pp. 357–365.
8. R. S. Varma and H. M. Meshram, Tetrahedron Lett., 1997, 38, 5427.
9. R. S. Varma and R. K. Saini, Tetrahedron Lett., 1997, 38, 2623.
10. R. S. Varma, M. Varma and A. K. Chatterjee, J. Chem. Soc., Perkin Trans. 1, 1993, 999.
11. R. S. Varma, A. K. Chatterjee and M. Varma, Tetrahedron Lett., 1993, 34, 3207.
12. R. S. Varma, J. B. Lamture and M. Varma, Tetrahedron Lett., 1993, 34, 3029.
13. R. S. Varma, A. K. Chatterjee and M. Varma, Tetrahedron Lett., 1993, 34, 4603.
14. R. S. Varma, R. Dahiya and R. K. Saini, Tetrahedron Lett., 1997, 38, 8819.
15. R. S. Varma and H. M. Meshram, Tetrahedron Lett., 1997, 38, 7973.
16. R. S. Varma and D. Kumar, Synth. Commun., 1999, 29 in press.
17. R. S. Varma and R. Dahiya, Tetrahedron Lett., 1997, 38, 2043.
18. R. S. Varma, R. K. Saini and R. Dahiya, Tetrahedron Lett., 1997, 38, 7823.
19. R. S. Varma and R. Dahiya, Tetrahedron Lett., 1998, 39, 1307.
20. R. S. Varma and R. K. Saini, Tetrahedron Lett., 1998, 39, 1481.
21. R. S. Varma, R. Dahiya and R. K. Saini, Tetrahedron Lett., 1997, 38, 7029.
22. R. S. Varma, D. Kumar and R. Dahiya, J. Chem. Res. (S), 1998, 324.
23. R. S. Varma, R. Dahiya and D. Kumar, Molecules Online, 1998, 2, 82.
24. R. S. Varma, R. K. Saini and H. M. Meshram, Tetrahedron Lett., 1997, 38, 6525.
25. (a) R. S. Varma, R. K. Saini and R. Dahiya, J. Chem. Res. (S), 1998, 120; (b) R. S. Varma and R. Dahiya, Synth. Commun., 1998, 28, 4087.
26. R. S. Varma, R. Dahiya and S. Kumar, Tetrahedron Lett., 1997, 38, 2039.
27. R. S. Varma and R. Dahiya, Synlett, 1997, 1245.
28. R. S. Varma, R. Dahiya and S. Kumar, Tetrahedron Lett., 1997, 38, 5131.
29. R. S. Varma and R. Dahiya, J. Org. Chem., 1998, 63, 8038.
30. R. S. Varma, R. K. Saini and D. Kumar, J. Chem. Res. (S), 1998, 348.
31. R. S. Varma and R. K. Saini, Synlett, 1997, 857.
32. R. S. Varma and R. K. Saini, Tetrahedron Lett., 1997, 38, 4337.
33. R. S. Varma and R. Dahiya, Tetrahedron, 1998, 54, 6293.
34. (a) D. Villemin and B. Labiad, Synth. Commun., 1990, 20, 3333; (b) D. Villemin and A. B. Alloum, Synth. Commun., 1990, 20, 3325; (c) D. Villemin and A. B. Alloum, Synth. Commun., 1991, 21, 63; (d) J. M. Lerestif, J. P. Bazureau and J. Hamelin, Synlett, 1995, 647; (e) M. Csiba, J. Cleophax, A. Loupy, J. Malthete and S. D. Gero, Tetrahedran Lett., 1993, 34, 1787; (f) D. Villemin, A. B. Alloum and F. Thibault-Starzyk, Synth. Commun., 1992, 22, 1359; (g) H. Benhaliliba, A. Derdour, J.-P. Bazureau, F. Texier-Boullet and J. Hamelin, Tetrahedron Lett., 1998, 39, 541; (h) M. Rahmouni, A. Derdour, J.-P. Bazureau and J. Hamelin, Tetrahedron Lett., 1994, 35, 4563 (, ); Synth. Commun., 1996, 26, 453; (i) E. Gutierrez, A. Loupy, G. Bram and E. Ruiz-Hitzky, Tetrahedron Lett., 1989, 30, 945; (j) D. Villemin and B. Labiad, Synth. Commun., 1992, 22, 2043; (k) A. I. Bosch, P. de la Cruez, E. Diez-Barra, A. Loupy and F. Langa, Synlett, 1995, 1259; (l) D. Villemin and B. Martin, J. Chem. Res. (S), 1994, 146.
35. D. A. Nelson, C. Devin, S. Hoffmann and A. Lau, Division of Chemical Education, ACS National Meeting, San Francisco, April 13–17, 1997, Abstract no. 101.
36. M. Balogh and P. Laszlo, Organic chemistry using clays, Springer, Berlin, 1993.
37. B. Perio, M. J. Dozias, P. Jacquault and J. Hamelin, Tetrahedron Lett., 1997, 38, 7867.
38. D. Bogdal, J. Pielichowski and A. Boron, Synlett, 1996, 873.
39. A. Vass, J. Toth and E. Pallai-Varsanyi, Effect of inorganic solid support for microwave assisted organic reactions, OR 19, presented at the International Conference on Microwave Chemistry, Prague, Czech Republic, Sept. 6–11, 1998.
40. D. Bogdal, J. Pielichowski and K. Jaskot, Synth. Commun., 1997, 27, 1553.
41. D. Bogdal, J. Pielichowski and K. Jaskot, Heterocycles, 1997, 45, 715.
42. P. de la Cruz, A. de la Hoz, L. M. Font, F. Langa and M. C. Perez-Rodriguez, Tetrahedron Lett., 1998, 39, 6053.
43. (a) R. Ballini, M. Bordoni, G. Bosica, R. Maggi and G. Sartori, Tetrahedron Lett., 1998, 39, 7587; (b) R. Ballini, G. Bosica and M. Parrini, Tetrahedron Lett., 1998, 39, 7963.
44. D. Subhas Bose and V. Lakshminarayana, Tetrahedron Lett., 1998, 39, 5631.
45. (a) Comprehensive Organic Synthesis (Oxidation), ed. B. M. Trost, Pergamon, New York, 1991, vol 7; (b) A. Oussaid and A. Loupy, J. Chem. Res. (S), 1997, 342.
46. (a) R. S. Varma and G. W. Kabalka, Heterocycles, 1986, 24, 2645; (b) G. W. Kabalka and R. S. Varma, Org. Prep. Proc. Int., 1987, 19, 283; (c) G. W. Kabalka, L. H. M. Guindi and R. S. Varma, Tetrahedron, 1990, 46, 7443.
47. D. Villemin and B. Martin, Synth. Commun., 1995, 25, 3135.
48. (a) V. Singh, J. Singh, P. Kaur and G. L. Kad, J. Chem. Res. (S), 1997, 58; (b) D. Bogdal, J. Chem. Res. (S), 1998, 468.
49. (a) G. H. Posner, A. W. Runquist and M. J. Chapdelaine, J. Org. Chem., 1977, 42, 1202 and references cited therein; (b) D. Barbry and S. Torchy, Tetrahedron Lett., 1997, 38, 2959.
50. A. Saoudi, J. Hamelin and H. Benhaoua, J. Chem. Res. (S), 1996, 492.
51. D. Villemin, M. Hammadi and B. Martin, Synth. Commun., 1996, 26, 2895.
52. A. L. Marrero-Terrero and A. Loupy, Synlett, 1996, 245.
53. R. S. Varma, D. Kumar and P. J. Liesen, J. Chem. Soc., Perkin Trans. 1, 1998, 4093.
54. M. Miller and G. Loudon, J. Org. Chem., 1975, 40, 126.
55. (a) J. H. Pomeroy and C. A. Craig, J. Am. Chem. Soc., 1959, 81, 6340; (b) D. T. Mowry, Chem. Rev., 1948, 42, 250; (c) H. M. Sampath Kumar, P. K. Mohanty, M. Suresh Kumar and J. S. Yadav, Synth. Commun., 1997, 27, 1327; (d) D. L. Clive, Chem. Commun., 1970, 1014; (e) P. J. Foley, J. Org. Chem., 1969, 34, 2805; (f) W. Lehnert, Tetrahedron Lett., 1971, 6, 559; (g) G. Rosini, G. Baccolini and S. Cacchi, J. Org. Chem., 1973, 38, 1060; (h) H. G. Foley and D. R. Dalton, J. Chem. Soc., Chem. Commun., 1973, 628; (i) D. Villemin, M. Lalaoui and A. B. Alloum, Chem. Ind. (London), 1991, 176; (j) R. S. Varma and K. P. Naicker, Molecules Online, 1998, 2, 94; (k) R. S. Varma, K. P. Naicker, D. Kumar, R. Dahiya and P. J. Liesen, J. Microwave Power Electromagnetic Energy, 1999, in press.
56. (a) S. Cannizzaro, Ann., 1853, 88, 129; (b) T. A. Geissman, Org. React., (NY), 1944, II, 94.
57. (a) C. G. Swain, A. L. Powell, W. A. Sheppard and C. R. Morgan, J. Am. Chem. Soc., 1979, 101, 3576; (b) S. K. Chung, J. Chem. Soc., Chem. Commun., 1982, 480; (c) E. C. Ashby, D. T. Coleman III and M. P. Gamasa, Tetrahedron Lett., 1983, 24, 851.
58. (a) R. S. Varma, K. P. Naicker and P. J. Liesen, Tetrahedron Lett., 1998, 39, 8437; (b) R. S. Varma, G. W. Kabalka, L. T. Evans and R. M. Pagni, Synth. Commun., 1985, 15, 279.
59. (a) J. Barrios, R. Rojas, A. R. Alcanrara and J. V. Sinisterra, J. Catal., 1988, 112, 528; (b) J. V. Sinisterra, J. M. Marinas, F. Riquelme and M. S. Arias, Tetrahedron, 1988, 44, 1431.
60. J. V. Sinisterra, A. Fuentes and J. M. Marinas, J. Org. Chem., 1987, 52, 3875.
61. J. V. Sinisterra and J. M. Marinas, Bull. Soc. Chim. Belg., 1987, 96, 293.
62. J. V. Sinisterra, React. Kinet. Catal. Lett., 1986, 30, 93.
63. R. S. Varma, K. P. Naicker and P. J. Liesen, Tetrahedron Lett., 1998, 39, 3977.
64. D. Villemin and F. Sauvaget, Synlett, 1994, 435.
65. A. Loupy and LeNgoc Thach, Synth. Commun., 1993, 23, 2571.
66. (a) K. E. Wilzbach, J. Am. Chem. Soc., 1957, 79, 1013; (b) J. R. Jones, Development of new microwave enhanced tritiation procedures, OR 9, presented at the International Conference on Microwave Chemistry, Prague, Czech Republic, Sept. 6–11, 1998; (c) N. H. Werstiuk, in Isotopes in the physical and biological sciences, ed. E. Buncel and J. R. Jones, Elsevier, Amsterdam, 1987, vol. 1A, pp. 124–155; (d) S. Anto, J. R. Jones and S. Y. Lu, Microwave enhanced acidcatalysed hydrogen/deuterium exchange reactions, P 34, presented at the International Conference on Microwave Chemistry, Prague, Czech Republic, Sept. 6–11, 1998.
67. S. Stone-Elander, N. Elander, J.-O. Thorell, P. Johnstrom, H. Ehrsson, A. Andersson and S. Kalhori, Monomodal microwave techniques in microscale organic chemistry, OR 2, presented at the International Conference on Microwave Chemistry, Prague, Czech Republic, Sept. 6–11, 1998 and references cited therein.
68. M. Liagre, A. Loupy, A. Oussaid, A. Petit and J. Cleophax, Scalingup of some typical organic reactions under focused microwaves, presented at the International Conference on Microwave Chemistry, Prague, Czech Republic, Sept. 6–11, 1998.
69. M. Mehdizadeh, Engineering and scale-up considerations for microwave induced reactions, in Proceedings: Microwave-Induced Reactions Workshop, Electric Power Research Institute, Palo Alto, CA, 1993, p. A-7.