Subscribe to RSS
DOI: 10.1055/s-2001-16052
2,3-Disubstituted and 2,3,5-Trisubstituted Benzofurans by Regioselective Pd-Catalyzed Cross-coupling Reactions; a Short Synthesis of Eupomatenoid-15
Publication History
Publication Date:
31 December 2001 (online)

2,3-Dibromobenzofuran (1) and 2,3,5-tribromobenzofuran (2) undergo regioselective Sonogashira- and Negishi-type cross-coupling reactions at the 2-position. Subsequent substitution reactions at C-3 are possible for the cross-coupling products obtained from compound 1. A regioselective functionalization of the 3,5-dibromobenzofurans derived from substrate 2 was achieved by an halogen-metal exchange which occurred selectively at the 3-position. In a conclusive reaction step cross-coupling reactions at C-5 were used to build up 2,3,5-trisubstituted benzofurans. As an example, the synthesis of eupomatenoid-15 (8) is described.
catalysis - cross-coupling - heterocycles - palladium - regioselectivity