Palladium-Catalyzed Alkenylation of Aromatic Heterocycles with Olefins. Synthesis of Functionalized Aromatic Heterocycles

Article abstract of DOI:10.1021/jo00318a005

Aromatic heterocycles such as furan, thiophene, benzofuran, benzothiophene, and N-acetylindole undergo facile palladium-assisted alkenylation with various olefins to produce mono- and/or dialkenylated heterocycles in high yield.With furan and thiophene, the reaction is regioselective, giving products substituted at the 2-position of the heterocycles, and is also stereoselective, giving E products when the substituent on the olefin is bulky.The reactions of benzofuran and N-acetylindole with olefins give cyclization products such as dibenzofuran and carbazole derivatives together with alkenylated products.The mechanistic implications with respect to these alkenylations are discussed.