Condensed heteroaromatic ring systems. XVIII. Palladium-catalyzed cross-coupling reaction of aryl bromides with (Z)-1-ethoxy-2-tributylstannylethene and its utilization for construction of condensed heteroaromatics
The palladium-catalyzedcross-coupling reaction of bromobenzenes or bromoheteroarenes such as pyridine, thiophene, indole with (Z)-1-ethoxy-2-tributylstannylethene gives good yields of the corresponding (Z)-1-ethoxy-2-(aryl and heteroaryl)ethenes. This method is effective for introducing an ethoxyethenyl group into an aromatic and heteroaromatic ring and is proved to have versatile utility for the