Synthesis of 1-ferrocenyl-2-aryl(heteroaryl)acetylenes and 2-ferrocenylindole derivatives via the Sonogashira–Heck–Cassar reaction

The Sonogashira–Heck–Cassar reaction of ferrocenylacetylene with aryl- and heteroaryl halides was shown to be a facile and convenient route for the synthesis of 1-ferrocenyl-2-aryl- and 1-ferrocenyl-2-heteroarylacetylenes in high yields. Additionally, annulation reactions of some of the 1-ferrocenylacetylene compounds gave 2-ferrocenyl-2-benzo[b]furan and 2-ferrocenylindoles in good yields.