Insertion Reactions of Ligands

Carbonylation reactions take place via coordination of the carbon monoxide molecule to the complex, formation of the cr-allyl compounds, and subsequent allyl migration to the CO group [scheme (7.106)]. 

Metal complexes in low oxidation states are often used as catalysts for reactions of allyl halides with CO, acetylenes, and olefins as well as their derivatives. In the first step of the reaction, there is an oxidative addition of CH2CHCH2X and the formation of the allyl complex  

Acetylene becomes coordinated in the vacated site because of the tt to 7 rearrangement of the complex. 

Organometallic Compounds, The Transition Elements, Vol. 2, Methuen, London (1968). 

Vrieze, in Dynamic Nuclear Magnetic Resonance Spectroscopy (L. M. Jackman and F. A. Cotton, eds.), p. 441, Academic Press, New York (1975). 

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