Enthalogenierung und regioselektive Phosphiniden‐Fragmentierung unsymmetrisch substituierter Methylenbisphosphane RXP–CH 2 –PXR′ mit Fe 2 (CO) 9

Dehalogenation and Regioselective Phosphinidene Fragmentation of Unsymmetrically Substituted Methylenebisphosphanes RXP-CH2-PXR′ with Fe2(CO)9 Reductive dehalogenation of the unsymmetrically substituted methylenebisphosphanes RXP–CH2-PR′X [X = Cl, Br; R = tBu, NEt2; R′ = 2,4,6-R”3C6H2 (R” = Me, tBu), NEt2, 2,6-iPr2C6-H3O, 2,6,4-tBu2MeC6H2O] with Fe2(CO)9 affords, depending on the reaction conditions employed, phosphido complexes [μ2-(RP-CH2-PR′)]Fe2(CO)6 (2) or phosphaalkene clusters (μ3-PR′)(η2,μ3-PRCH2)Fe3(CO)9(6) or [(μ-PR)(η2,μ3PR′CH2)]Fe3-(CO)9 (7), respectively, by regioselective phosphinidene fragmentation of the RP–CH2-PR′ skeletons. The unstable cluster compounds [μ3-PR′–CH2–PR)]Fe3(CO)9 (4) are formed as intermediate products. X-ray structural analysis of 6c (R = tBu; R′ = NEt2) reveals a flat butterfly (μ3-PR)Fe3 structure bridged by the phosphaalkene ligand tBuP = CH2 with a short P = C distance [177.2(4) pm].