Reactivity of metal-bound dihydrogen

Activation of Substrates with Non-Polar Single Bonds 

Bianchini and his co-workers [41] have demonstrated H2 transfer to an alkene such as dimethyl maleate with [Rh(P(CH2CH2PPh2)3H2]. Jackson et al. [42] have reported that /ac-(nbd)M(CO)3(H2) (M = Cr, Mo, or W, nbd = norbor-nadiene), which is generated by photolysis of (nbd)M(CO)4 in liquid Xe in the presence of H2/D2, undergoes hydrogenation of NBD to yield endo deuterated nortricyclene upon warming (Eq. 2.16). On the other hand, H2/D2 transfer to the diene in mer-(nbd)M(CO)3(H2) leads to formation of the endo deuterated nor-bornene (Eq. 2.17). This observed stereospecificity of the catalytic hydrogenation is consistent with the intramolecular transfer of H2 to the bound NBD. 

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