3-Aryl-2,4-pentanediones from 3,5-Dimethyl-4-iodoisoxazoles: An Application of a Palladium-Catalyzed Cross-Coupling Reaction

References

• Contribution No. 854 from the Institute of Organic Chemistry.
   Google Scholar
• Grünanger , P. and Vita-Finzi , P. 1991 . “The Chemistry of Heterocyclic Compounds,” , 391 – 493 . New York : John Wiley and Sons, Inc. .
   Google Scholar
• Stille , J. K. 1986 . Angew. Chem., Int. Ed. Engl. , 25 : 508 For coupling of organostannanes see and references therein.
   Web of Science ®Google Scholar
• Stille , J. K. 1985 . Pure Appl. Chem. , 57 : 1771
   Web of Science ®Google Scholar
• Sharp , M. J. and Snieckus , V. 1985 . Tetrahedron Lett. , 26 : 5997 For coupling of organoboronic acids see
   Google Scholar
• Thompson , W. J. and Gaudino , J. 1984 . J. Org. Chem. , 49 : 5237 – 5243 .
   Web of Science ®Google Scholar
• Miyaura , N. , Yanagi , T. and Suzuki , A. 1981 . Synthetic Comm. , 11 : 513
   Web of Science ®Google Scholar
• Negishi , E. , King , A. O. and Okukado , N. 1977 . J. Org. Chem. , 42 : 1821 For organozinc and Grignard coupling reactions see
   Web of Science ®Google Scholar
• Kochitkov , N. K. , Sokolov , S. D. and Vagurtova , N. M. 1961 . Zhur. Obshch. Khim. , 31 : 2326
   Google Scholar
• Chem. Abs. , 56 3467 a
   Google Scholar
• Yamanaka , H. , Shiraiwa , M. , Yamamoto , E. and Sokamoto , T. 1981 . Chem. Pharm. Bull. Jpn. , 29 : 3543 – 3547 . The coupling of 3,5-dimethyl-4-iodoisoxazole with alkynes in the presence of a palladium catalyst has been reported.
   Google Scholar
• Nakamura , N. , Tajima , Y. and Sakai , K. 1982 . Heterocycles , 17 : 235 Direct phenylation of 4-unsubstituted isoxazoles with either benzene or iodobenzene in the presence of palladium acetate or palladium-charcoal has been reported.
   Google Scholar
• Stagno , d' and Alcontres , G. 1950 . Gazz. Chim. Ital. , 80 : 441
   Google Scholar
• Auricchio , S. , Vajna de Pava , O. and Vera , E. 1979 . Synthesis , 116
   Google Scholar
• The coupling between arylboronic acid and 3,5-dimethyl-4-iodoisoxazole was carried out in a 1:1 mixture of 1,2-dimethoxyethane and water in the presence of three equivalents of sodium bicarbonate at 80°C for 18 h under nitrogen atmosphere. The products were purified by flash chromatography.
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• The coupling with organostannanes was carried out in toluene at 90°C for 18 h under nitrogen atmosphere. The reaction mixture was then diluted with ethyl acetate and stirred over 10% aqueous potassium fluoride solution to facilitate the separation of tributyltin iodide. The products were purified by flash chromatography.
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• The zinc species were prepared as described in ref. 5 and then 3,5-dimethyl-4-iodoisoxazole and the palladium catalyst were added and the reaction mixture was heated at the reflux temperature.
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• The reductive-cleavage of the 3,5-dimethyl-4-arylisoxazoles was performed in the presence of wet Raney nickel, equal amount in weight to the substrate. The subsequent acid hydrolysis was done in a 1:1 mixture of ethanol/water in the presence of three equivalents of the oxalic acid or 1:1 mixture of ethanol/2N hydrochloric acid.
   Google Scholar
• Bruggink , A. and McKillop , A. 1975 . Tetrahedron , 31 : 2607
   Web of Science ®Google Scholar
• D'Erba , C. , Novi , M. , Petrillo , G. , Tavani , C. and Bellandi , P. 1991 . Tetrahedron , 47 : 333 and references therein.
   Google Scholar