Reactions between methyl-, acetyl-, and phenyl-pentacarbonylmanganese and acetylenes

Abstract

Methyl-, acetyl-, and phenyl-pentacarbonylmanganese undergo cis-addition reactions with the acetylenes PhC⋮CH, RO₂C·C⋮C·CO₂R (R = Me or H), MeO₂C·C⋮CH, or CH⋮C·CHO to afford stable (vinyl ketone) tetracarbonylmanganese derivatives, in which the keto-group is co-ordinated to a manganese atom. The reactions with phenylacetylene give, in addition, low yields of 2,4,6-trisubstituted-π-pyranyltricarbonylmanganese complexes. The ¹H n.m.r. and i.r. spectra of these new complexes are described.