Synthesis, Characterization and Catalytic Application of Iron Complexes Modified by Monodentate Phosphane Ligands

In the present study, the properties of new monodentate phosphane ligands with a N,N-diphenyl-1H-pyrrol-1-amine moiety have been investigated. The ligands are easily accessible by lithiation of N,N-diphenyl-1H-pyrrol-1-amine in the 2-position and by quenching with phosphane chlorides (2: R = tBu, 3: R = Ph). After characterization of the ligands, their coordination to iron carbonyls has been studied. The ligands coordinate through the phosphorus in a monodentate fashion to the iron to realize complexes with the (L)Fe(CO)(4) motif. Initial catalytic experiments have been performed; the iron-catalyzed reduction of alkynes to alkenes with excellent selectivities to the corresponding alkenes has been achieved.