Hydroamination by Attack on -ir-Olefin and Alkyne Complexes

Hydroamination by Attack of Amines on Tt-Ailyl and rr-Benzyi Complexes 

Hydroaminations of 1,3-dienes and of vinylarenes occur by a different mode of nucleophilic attack. In this case, the attack occurs on a formally anionic ir-allyl or ir-benzyl 

Hydroamination by Insertions of Olefins into Meta/ Amides 

As discussed in Chapter 9, the insertion of olefins and alk)nes into metal-amido complexes is limited to a few examples. Such insertion reactions are proposed to occur as part of the mechanism of the hydroamination of norbomene catalyzed by an iridium(I) complex and as part of the hydroamination of alkenes and alkynes catalyzed by lanthanide and actinide metal complexes. This reaction was clearly shown to occur with the iridium(I) amido complex formed by oxidative addition of aniline, and this insertion process is presented in Chapter 9. The mechanism of the most active Ir(I) catalyst system for this process involving added fluoride is imknown. 

Detailed studies of the stereochemistry of the cyclization process indicate that a second amine is likely coordinated to the metal center during the insertion process and primary KIE values for N-H and N-D suggest that protonolysis occurs in concert with insertion. A possible mechanism that was proposed to account for this role of a second amine is showm in Equation 16.94. Hydrogen bonding between this coordinated amine and the amido complex is proposed to accelerate the insertion step. 

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