Umlagerungsreaktionen von Metallodiphosphapropenen des Typs (η 5 ‐C 5 Me 5 )(CO) 2 FeP(SiMe 3 ) — P = C(R)(SiMe 3 ) (R = SiMe 3 , Ph)

Rearrangements of the Metallodiphosphapropenes (η 5 ‐C 5 Me 5 )(CO) 2 FeP(SiMe 3 — P = C(R)(SiMe 3 ) (R = SiMe 3 , Ph) Heating of a methylcyclohexane solution of (η 5 ‐C 5 Me 5 )‐(CO) 2 FeP(SiMe 3 ) — P = C(SiMe 3 ) 2 ( 1a ) gives rise to the insertion of the P = C moiety into the CH bond of a ring methyl group with formation of the chelate complex η 5 ‐ηC 5 Me 4 CH 2 P‐[CH(SiMe 3 ) 2 ]P(SiMe 3 )Fe(CO) 2 ( 2 ) which is converted into the pentacarbonylchromium derivative [ 5 ‐C 5 Me 4 CH 2 P[CH‐(SiMe 3 ) 2 ]P(SiMe 3 )[Cr(CO) 5 ]Fe(CO) 2 ] ( 3 ). In contrast, a similar treatment of ( 5 ‐C 5 Me 5 )(CO) 2 FeP(SiMe 3 ) — P = C(Ph)(SiMe 3 ) ( 1 b ) furnishes the diphosphirane ( 5 ‐C 5 Me 5 )(CO) 2 FeP — C(Ph)‐SiMe 3 ) — P (SiMe 3 ) ( 5 ). By chromatography of its (CO) 5 Cr adduct 6 , the P — Si bond is hydrolyzed to give the (diphosphirane)‐chromium complex [( 5 ‐C 5 Me 5 )(CO) 2 FeP‐C(Ph)(SiMe 3 )P(H)]‐Cr(CO) 5 ( 8 ). The molecular structures of 3 and 8 are determined by single‐crystal X‐ray analysis.