M-E-CH groups

The chemistry of alkoxides, amides, and related groups has been reviewed [94,95], 

8-10 metals are similar to each other [97]. In other words, the higher instability of alkoxo derivatives for late transition metals, as compared to alkyls, is kinetic in nature. 

Thiolates. The thioaldehyde hydrido complexes [(C5Me5)2Ta(H)(j7 -S=CHR)] seem to be in rapid equilibrium with the corresponding 16-electron thiolate species [(C5Me5)2Ta(SCH2R)] through a yd-H migratory insertion/elimination process [100]. The low concentration of the latter precludes its direct observation. 

Amido complexes. yd-H elimination from the monomeric iridium amido complex [Ir(NPhBz)(CO)(PPh3)2] has been observed and the products are the hydrido complex [IrH(CO)(PPh3)2] and PhCH=NPh. Kinetic studies indicate that dissociation 

Enolates. The /f-H elimination from enolates involves formal elimination of ketene, and has been recognized in the decomposition of [Ru(Me) OC(CH2)H (PMe3)4] to [Ru(Me)(H)(PMe3)4], upon warming it in solution to 65°C. When this thermolysis was run in the presence of tert-butyl alcohol as a trap, tert-butyl acetate was formed in 10-15% yield, consistent with the formation of ketene during the course of the reaction [106]. 

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