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‐CH 2 ‐PXR′ with Fe 2 (CO) 9 Reductive dehalogenation of the unsymmetrically substituted methylenebisphosphanes RXP–CH 2 ‐PR′X [X = Cl, Br; R = t Bu, NEt 2 ; R′ = 2,4,6‐R” 3 C 6 H 2 (R” = Me, t Bu), NEt 2 , 2,6‐ i Pr 2 C 6 ‐H 3 O, 2,6,4‐ t Bu 2 MeC 6 H 2 O] with Fe 2 (CO) 9 affords, depending on the reaction conditions employed, phosphido complexes [μ 2 ‐(RP‐CH 2 ‐PR′)]Fe 2 (CO) 6 ( 2 ) or phosphaalkene clusters (μ3‐PR′)(η 2 ,μ 3 ‐PRCH 2 )Fe 3 (CO) 9 ( 6 ) or [(μ‐PR)(η 2 ,μ 3 PR′CH 2 )]Fe 3 ‐(CO) 9 ( 7 ), respectively, by regioselective phosphinidene fragmentation of the RP–CH 2 ‐PR′ skeletons. The unstable cluster compounds [μ 3 ‐PR′–CH 2 –PR)]Fe 3 (CO) 9 ( 4 ) are formed as intermediate products. X‐ray structural analysis of 6c (R = t Bu; R′ = NEt 2 ) reveals a flat butterfly (μ 3 ‐PR)Fe 3 structure bridged by the phosphaalkene ligand t BuP = CH 2 with a short P = C distance [177.2(4) pm].