Activation of σ-Bonds by Group 13/Ylide-Based Ambiphiles: Understanding and Design

The factors controlling the activation of σ-bonds promoted by hidden Frustrated Lewis Pairs have been computationally explored using quantum chemical tools. To this end, the influence of both the nature of the group 13 element acting as Lewis acid as well as the cooperative action of the Lewis antagonists on the bond activation was quantitatively analyzed by means of the activation strain model of reactivity in combination with the energy decomposition analysis method. It is found that while the activation of the polar E^X−H bonds (E¹⁵=group 15 element; E¹⁶=group 16 element) is feasible, the analogous processes involving non-polar E¹⁴−H bonds (CH₄, SiH₄ or H₂) proceed with much higher barriers. Nevertheless, these processes, and in particular the dihydrogen activation, can be realizable (i. e. proceeding with a feasible barrier) through rational design.