Metallinduzierte und basenkatalysierte 2‐Propinyl‐Allenyl‐Umlagerung in [(HCCCH 2 )(2,4,6‐ t Bu 3 C 6 H 2 O)]PMoCP(CO) 2

Metal‐Induced and Base‐Catalyzed 2‐Propynyl‐Allenyl Rearrangement in [(HCCCH 2 )(2,4,6‐ t Bu 3 C 6 H 2 O)]PMoCP(CO) 2 The synthesis and reactivity of [(HCCCH 2 )(2,4,6‐ t Bu 3 1‐C 6 H 2 O)]PMoCp(CO) 2 ( 3 ) is described. [(HCCCH 2 )(R)]PCl ( 1 ) reacts with NaMoCp(CO) 3 ( 2 ) to afford the s̀ 3 ,λ 4 1‐phosphanediyl compounds 3 . With NEt 3 a prototropic rearrangement of the 2‐propynyl ligand of 3 to an allenyl group in [(H 2 CCCH)(R)]PMoCp(CO) 2 ( 5 ) is observed. However, with Cr(CO) 5 · THF a metal‐induced rearrangement of the 2‐propynyl unit in 3 yields η 3 ‐{(2,4,6‐ t Bu 3 C 6 H 2 O)[(CO) 5 Cr]PCHCCH 2 }MoCp(CO) 2 ( 7 ). Complex 7 contains a 1‐phosphaallyl system, which is functionalized by an exocyclic CC double bond X‐ray structure analyses of 3 and 7 are performed.