N-alkyl-4-boronopyridinium salts as thermally stable and reusable amide condensation catalysts

Organic Letters

Volumn 7, Issue 22, 2005, Pages 5043-5046

  Maki, Toshikatsu ^a   Ishihara, Kazuaki ^a   Yamamoto, Hisashi ^b  

^a NAGOYA UNIVERSITY   (Japan)

^b UNIVERSITY OF CHICAGO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 27644465867     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol052060l     Document Type: Article

References (14)

1. (a) Ishihara, K.; Ohara, S.; Yamamoto, H. J. Org. Chem. 1996, 61, 4196-4197.
2. (b) Ishihara, K.; Ohara, S.; Yamamoto, H. Macromolecules 2000, 33, 3511-3513.
3. (c) Ishihara, K.; Ohara, S.; Yamamoto, H. Org. Synth. 2002, 79, 176-185.
4. (d) Maki, T.; Ishihara, K.; Yamamoto, H. Synlett 2004, 1355-1358.
5. (e) Ishihara, K. Boronic Acids; Hall, D. G., Ed.; Wiley-VCH: Weinheim, Germany, 2005; pp 377-409.
6. Ishihara, K.; Kondo, S.; Yamamoto, H. Synlett 2001, 1371-1374.
7. (a) Ohara, S.; Ishihara, K.; Yamamoto, H. The 78th Spring Meeting of Chemistry Society of Japan, 2000, 3-B5-10.
8. (b) Ishihara, K.; Yamamoto, H. Jpn. Kokai Tokkyo Koho JP 2001-270939 (2001-10-02), Application: JP 2000-87495 (2000-03-27).
9. Latta, R.; Springsteen, G.; Wang, B. Synthesis 2001, 1611-1613.
10. (a) Ishiyama, T.; Ishida, K.; Miyaura, N. Tetrahedron 2001, 57, 9813-9816.
11. (b) Bouillon, A.; Lancelot, J.-C; de Oliveria Santos, J. S.; Collot, V.; Bovy, P. R.; Rault, S. Tetrahedon 2003, 59, 10043-10049.
12. (c) Gros, P.; Doudouth, A.; Fort, Y. Tetrahedron Lett. 2004, 45, 6239-6241.
13. 1H NMR spectral analysis.
14. 4 the amide condensation of less-reactive benzoic acid (1 equiv) with benzylamine (1.2 equiv) gave the product in 92% isolated yield in the presence of 1 mol % of 3-pyridineboronic acid or 3 in toluene. However, we could not duplicate Wang's results and obtained the amide in less than 10% yield under the same conditions.