Metal carbonyl-promoted reactions of ferrocenylacetylene with sulfur to form thiophene, dithiine, thioketone and vinylthioketone derivatives

Photolysis of a hexane solution of ferrocenylacetylene and sulfur powder in presence of Cr(CO)6 resulted in the formation of 2,6-diferrocenyldithiine and 2,5-diferrocenylthiophene. Similar reactions with Mo(CO)6 or W(CO)6 gave only the thiophene derivative. Formation of ferrocenyl-substituted thioketone complexes was observed in the reaction of ferrocenylacetylene with water and sulfur, in presence of W(CO)6. Use of D2O confirmed water as source of protons for the conversion of acetylenic CH to CH3.