Synthesis of Coumarins Through Zinc Chloride-Catalyzed Hydroarylation of Acetylenic Esters by Phenols

Synthesis of Coumarins Through Zinc Chloride-Catalyzed Hydroarylation of Acetylenic Esters by Phenols

Leão, Raquel A. C.; Moraes, Paula de F. de; Pedro, Marcella C. B. C.; Costa, Paulo R. R.

Abstract:

Coumarins comprise a class of natural products and many of them exhibit a broad range of biological activities. Several routes have been described to prepare coumarins. In 1965 Kaufman and colworkers reported the hydroarylation of the ethyl propiolate (2a) by fluoroglucinol (1a) in the presence of stoichiometric amount of ZnCl2 leading to the coumarin 3a in good yield. The protocol reported by Kaufman was very few explored in the literature and no attempts to perform the hydroarylation in the presence of catalytic amounts of ZnCl2 was described. Herein we wish to report the zinc chloride-catalyzed hydroarylation of acetylenic esters 2 by phenols 1 leading to coumarins 3.

Coumarins comprise a class of natural products and many of them exhibit a broad range of biological activities. Several routes have been described to prepare coumarins. In 1965 Kaufman and colworkers reported the hydroarylation of the ethyl propiolate (2a) by fluoroglucinol (1a) in the presence of stoichiometric amount of ZnCl2 leading to the coumarin 3a in good yield. The protocol reported by Kaufman was very few explored in the literature and no attempts to perform the hydroarylation in the presence of catalytic amounts of ZnCl2 was described. Herein we wish to report the zinc chloride-catalyzed hydroarylation of acetylenic esters 2 by phenols 1 leading to coumarins 3.

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DOI: 10.5151/chempro-14bmos-R0072-1

Referências bibliográficas

• [1] 1 a) Volz, N.; Toräng, J.; Hinz, S.; Bräseb, S.; Müllera, C. E. Bioorg. Med. Chem. 2009, 17, 2842. b) Borges, F.; Roleira, F.; Milhazes, N.; Santana, L.; Uriarte, E. Curr. Med. Chem. 2005, 12, 887.
• [2] 2 a) Kaufman, K. D.; Kelly, R. C. Heterocycl. Chem. 1965, 2, 91. b) Oyamada, J.; Kitamura, T. Tetrahedron 2006, 62, 6918. c) Trost, B. M.; Toste, F. D.; Greenman, .K. J. Am. Chem. Soc. 2003, 125, 4518.

Como citar:

Leão, Raquel A. C.; Moraes, Paula de F. de; Pedro, Marcella C. B. C.; Costa, Paulo R. R.; "Synthesis of Coumarins Through Zinc Chloride-Catalyzed Hydroarylation of Acetylenic Esters by Phenols", p-72-72. In: In Blucher Chemistry Proceedings, São Paulo, v. 1, n. 1, Setembro.2013. São Paulo: Blucher, 2013.
ISSN 23184043, DOI 10.5151/chempro-14bmos-R0072-1