Metallacyclobutene aus η²‐Cyclopropen‐Komplexen des Titanocens und Zirkonocens

Metallacyclobutenes via η 2 ‐Cyclopropene Complexes of Titanocene and Zirconocene (η 2 ‐Cyclopropene)(trimethylposphane) complexes of titanocene ( 4 , 5 ) and zirconocene ( 8 ) are obtained in good yields by the reaction of 1,2‐diphenylcyclopropene ( 2 ) or 4,8‐dioxaspiro[2.5]oct‐1‐ene ( 3 ) with bis(trimethylphosphane)titanocene ( 1 ) and (1‐butene)(trimethylphosphane)zirconocene ( 7 ), respectively. In solution the new complexes 4 and 8 rearrange smoothly above room temperature to give the metallacyclobutene derivatives 6 and 9 . All new compounds were characterized by spectroscopic methods ( 31 P, 1 H, 13 C NMR), and the crystal structure of 9 was determined by an X‐ray analysis.