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.