Design and Catalytic Applications of Photoactivated Frustrated Lewis Pairs

ended

In 2006 Douglas Stephan described the first reversible metal-free hydrogen activation via frustrated Lewis pairs (FLPs). In these pairs, the presence of bulky substituents in both the Lewis acid and base precludes the formation of the Lewis pair, creating a highly polarised pocket that can activate small and organic molecules. Although mostly of the FLPs seem to react via two electron processes, a few FLPs have shown radical reactivity, namely frustrated radical pair (FRP). This radical reactivity has been already used in synthetic applications of interest like C-C bond formation. However, there are very limited of examples of main group FRPs, which formation depend entirely of the nature of the substituents of the Lewis acid and Base. Another interesting type of FLPs are those in which either the LA or the LB is constituted by a transition metal (TM), which eases the possibility of catalytic applications, due to the high versatility and reactivity of TMs. Regarding transition metal only FLP (TMOFLPs), the first example was described recently by the group of Jesus Campos. Constituted by Au/Pt as LB and LA and LB respectively, this pairs have shown activity in the activation of small molecules like hydrogen or acetylene. In this project, the family of known MG FRPs will be extended with the rational design of a family of photoactivated FRPs. This novel FRPs will be then tested in the activation of small molecules and C-O bond activation reactions. Following this approach, a family of hybrid transition metal/main group photoactivated FRPs will be prepared, and their reactivity will be tested both in small molecules activation and potential catalytic applications of interest such as ethereal C-O bond activation. Finally, a family of photoactivated TMOFLPs will be prepared. The family of known TMOFLPs will be extended to 1st row TMs, and the photoexcitation of these pairs will be explored for unprecedented catalytic applications.