Desulfurization and ortho-metalation reactions of dimanganese decacarbonyl

Thiobenzophenone, and 4,4′-disubstituted derivatives having moderately electron-donating (methyl, methoxy) or electron-withdrawing (fluoro) groups, react with dimanganese decacarbonyl in refluxing heptane to produce olefins (and a sulfur manganese carbonyl complex) in good yield. 4,4′-Bis(dialkylamino)thiobenzophenones reacted with the metal carbonyl to give sulfur-donor ligand ortho-metalated complexes as the major product and 4,4′-bis(dialkylamino)diphenylmethanes as by-products. A mechanistic scheme is proposed for these reactions.