Regioselective double Suzuki couplings of 4,5-dibromothiophene-2-carboxaldehyde

Tetrahedron Letters

Volumn 48, Issue 46, 2007, Pages 8108-8110

  Handy, Scott T ^a   Mayi, Diyar ^a  

^a MIDDLE TENNESSEE STATE UNIVERSITY   (United States)

Author keywords

Dehalogenation; One pot; Regioselective; Suzuki coupling; Thiophenes

Indexed keywords

4,5 DIBROMOTHIOPHENE 2 CARBOXALDEHYDE; ALDEHYDE DERIVATIVE; HALOGEN; UNCLASSIFIED DRUG; WATER;

ARTICLE; CHEMICAL REACTION; CHEMICAL STRUCTURE; DEHALOGENATION; STATISTICAL SIGNIFICANCE; SUZUKI REACTION; SYNTHESIS;

EID: 35348855632     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2007.09.114     Document Type: Article

References (14)

1. In: Negishi E. (Ed). Handbook of Organopalladium Chemistry for Organic Chemistry Vol. 1 (2002), John Wiley & Sons, New York
2. Handy S.T., and Sabatini J.J. Org. Lett. 8 (2006) 1537-1539
3. Handy S.T., and Zhang Y. Synthesis (2007) 3883-3887
4. Handy, S. T.; Wilson, T.; Muth, A. J. Org. Chem. 72, in press.
5. For examples from other groups, see:. Kaswasaki I., Yamashita M., and Ohta S. Chem. Commun. (1994) 2085-2086
6. Beletskaya I.P., Tsvetkov A.V., Tsvetkov P.V., Latyshev G.V., and Lukashev N.V. Russ. Chem. Bull. 54 (2005) 215-219
7. Duan X.F., Li X.H., Li F.Y., and Huang C.H. Synthesis (2004) 2614-2616
8. Handy S.T., and Zhang Y. Chem. Commun. (2006) 299-301
9. No previous efforts have been reported on the regioselective coupling of thiophene aldehyde 3, although one report has investigated 3,5-dibromothiophene-2-carboxaldehyde. Kodani T., Matsude K., Yamada T., Kobatake S., and Irie M. J. Am. Chem. Soc. 122 (2000) 9631-9637
10. Interestingly, the formation of 4 does not appear to be the result of dehalogenation of 5, since resubjection of 5 to the reaction conditions, but in the absence of a boronic acid, does not result in the formation of 4 and resubjection of 5 to the reaction conditions in the presence of a boronic acid only affords the product of a second Suzuki coupling.
11. The identity of compound 4 was confirmed by comparison to the spectral data for this compound reported in the literature. Alson D.A., Najera C., and Pacheco M.C. J. Org. Chem. 67 (2002) 5588-5594 Hydrogenolysis of 5 also affords compound 4, thereby confirming the regioselectivity of the first coupling
12. Netherton M.R., and Fu G.C. Org. Lett. 3 (2001) 4295-4298
13. Representative procedure: To a solution of dibromothiophene aldehyde 3 (0.3 mmol) in 4 mL of dioxane/water (6:1 v/v) was added boronic acid (0.33 mmol), potassium carbonate (0.6 mmol), and tetrakis(triphenylphosphine) palladium(0) (0.015 mmol). The reaction mixture was heated to 90 °C overnight (12 h) and shaken on an orbital shaker. At this point, the second boronic acid (0.45 mmol) and more potassium carbonate (0.66 mmol) were added and the reaction was shaken and heated for an additional 12 h. The reaction was then cooled to room temperature and partitioned between ether and water. The organic layer was dried with magnesium sulfate, filtered, and concentrated in vacuo. The crude residue was purified by column chromatography using 20% ether/hexanes as the eluent to afford the double-coupled product.
14. 22OS 406.1391; found, 406.1390.