Stoichiometric reactions of isocyanides with metal alkyls

1 Stoichiometric reactions of isocyanides with metal alkyls 

The iminoacyl complexes arising from the insertion of isocyanides exhibit interesting chemical and structural properties. A number of binding structures of iminoacyl ligand including rj, ri, or modes have been recognized as 

In general, the iminoacyl complexes are thermodynamically more stable than the acyl complexes, so that deinsertion of isocyanides from iminoacyl complexes has not been observed in contrast to the facile a-elimination of CO from acyl complexes. The removal of a halide ligand from a neutral iminoacylpalladium complex by treatment with AgBp4 affords the corresponding cationic iminoacyl complex from which no deinsertion of the isocyanide proceeded (Eq. 7.12) [61b]. 

Relative susceptibility of isocyanide and carbonyl ligands to insertion depends on reaction systems. The greater thermodynamic stability of the iminoacyl complexes than the acyl complexes was demonstrated by thermal isomerization of acyl(isocyanide)molybdenum to iminoacyl(carbonyl)molybdenum complexes (Eq. 7.13) [94]. 

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