Ligands Bound by a Single Atom

Insertions of Ligands Bound by a Single Atom. 2.1.1. Insertions of Carbon Monoxide 

The transformation of an alkylmetal carbonyl complex into a metal-acyl complex is one of the most common types of migratory insertion reactions (Equation 9.3). Examples of CO insertion into metal-alkyl complexes are known for all of the transition elements. This reaction class has been the subject of review articles. These reactions occur by a family of diverse, delicately balanced reaction pathways the dominant mechanism depends on the reaction conditions, especially the solvent. Although these pathways are now imderstood in considerable detail, the precise identities of the intermediates in some of these reaction pathways are unknown. 

Examples of CO Insertions into Metal-Hydrocarbyl Complexes 

As noted in the previous paragraph, insertions of CO into metal-alkyl complexes are known for all of the transition metals. Two examples of these reactions are shown in Equations 9.4 and 9.5. The insertion of CO into the alkylmanganese carbonyl complex in Equation 9.4 is one of earliest CO insertion processes to be identified. Insertion of CO involving the classic Fp alkyl complex in Equation 9.5, which also contains a metal center, is a second well-studied example of this class of reaction.  

The insertion of CO into metal-alkoxide, -amide, and -silyl bonds is much less common than the insertion of CO into metal-alkyl and metal-aryl bonds. Selected insertions 

---