The reaction of 1,3-dienes with phenylmanganese carbonyl

Abstract

Reaction of C₆H₅Mn(CO)₅ with [1,1,4,4-²H₄]buta-1,3-diene and trans-penta-1,3-diene gives 3-benzoyl-1-trideuteriomethyl-π-[3-²H₁] allyltetracarbonylmanganese and 3-benzoyl-1-ethyl-π-allyltetracarbonylmanganese, respectively. These complexes readily undergo a thermal decarbonylation to give 5-ethyl-2-phenyl-π-1-oxa-pentadienyltricarbonylmanganese and 5-trideuteriomethyl-2-phenyl-π-1-oxa[3-²H₁] pentadienyltricarbonyl-manganese, respectively. The mechanism of the reaction of 1,3-dienes with C₆H₅Mn(CO)₅ is discussed in the light of these observations. Bromination of 3-benzoyl-1-ethyl-π-allyltetracarbonylmanganese affords 1-benzoyl-1,2,3-tribromobutane.