From stabilization to activation: Different applications of a methylene-bridged frustrated Lewis pair

Since the discovery in 2006 that frustrated Lewis pairs (FLPs) can heterolytically split dihydrogen[1], a new field of main-group chemistry and catalysis was born. Since then, FLPs have been reported to activate a large... [ view full abstract ]

Since the discovery in 2006 that frustrated Lewis pairs (FLPs) can heterolytically split dihydrogen^[1], a new field of main-group chemistry and catalysis was born. Since then, FLPs have been reported to activate a large variety of homo- and heteronuclear bonds, which can be applied as key step in a broad range of FLP catalyzed reactions.

Interestingly, FLPs can also be utilized as ambiphilic ligands^[2] that are able to form Z-type coordination modes, where the ligand coordinates to the Lewis acid, forming a dative metal-ligand bond. We found that our methylene-bridged FLP is capable of coordinating to different coinage metals with subsequent cleavage of a metal-halide bond.

Another remarkable application of frustrated Lewis pairs is their application as stabilizing ligands for highly reactive intermediates. In this respect, we became interested in phosphazides, which are intermediates in the Staudinger reaction that readily release dinitrogen resulting in the formation of iminophosphoranes.^[3]

In this presentation, we report the variety in applications of our methylene-bridged frustrated Lewis pair. This FLP is utilized in main group catalysis such as catalytic dehydrogenation, but also as stabilizing agent for reactive intermediates. These applications are fully supported with DFT calculations of the complete reaction profile, which generates new insight into these essential reactions in main-group chemistry.

[1] Welch, G.C., San Juan, R.R., Masuda, J.D., Stephan, D.W., Science, 314 (2006) 1124.

[2] Bouhadir, G., Bourissou, D., Chem. Soc. Rev., 45 (2016) 1065.

[3] (a) Bourissou, D., Angew. Chem. Int. Ed., 46 (2007) 3333. (b) Erker, G., Dalton Trans., 39 (2010) 7556. (c) Erker, G., Chem. Commun., 48 (2012) 11739. (d) Uhl, W., Eur. J. Inorg. Chem., 26 (2016) 4170.

E-mail: d.h.a.boom@uva.nl j.c.slootweg@uva.nl