Frustrated Lewis Pair Chemistry and Catalysis

Frustrated Lewis Pairs (FLPs) comprise sterically hindered Lewis acids and Lewis bases that cannot form a stable adduct, instead cooperating to activate small molecules under mild, metal-free conditions. Since their discovery, FLPs have been proven capable of cleaving H–H, Si–H and other bonds via heterolytic pathways, enabling catalytic hydrogenation, hydrosilylation, reductive amination and CO₂ utilisation without transition metals. Key reagents include bulky boranes such as B(C₆F₅)₃ paired with phosphines or amines, and more recently novel main-group acids. Mechanistically, FLP systems proceed via two-electron concerted pathways or, as now appreciated, single-electron-transfer processes that generate radical ion pairs. Advances in catalyst design, mechanistic understanding and substrate scope have driven applications in fine-chemical synthesis, polymer functionalisation and sustainable transformations, emphasising global relevance in green chemistry and energy storage.

Research from Nature Portfolio

Recent studies have harnessed machine learning to accelerate the discovery of tailored FLP catalysts. A large virtual library of triarylboranes was computationally screened to predict parameters governing Lewis acidity and steric profile. Experimentally validated, the optimised borane enabled the catalytic reductive alkylation of aniline-derived amino acids and protected peptides with H₂, generating only water as by-product. This work demonstrates that a combined theoretical–experimental workflow can rapidly identify highly active, functional-group-tolerant main-group catalysts for hydrogen-mediated transformations.

Frustrated Lewis Pair Chemistry and Catalysis publication trend

The graph below shows the total number of articles in frustrated lewis pair chemistry and catalysis across all publications each year (not limited to Nature Index journals).

Technical terms

Frustrated Lewis Pair (FLP): A combination of a Lewis acid and a Lewis base prevented from forming a classical adduct by steric hindrance, enabling cooperative activation of small molecules.

Lewis acid: An electron-pair acceptor species that coordinates to electron-rich centres in substrates or bases.

Lewis base: An electron-pair donor species that coordinates to electron-deficient centres in acids or substrates.

Single-electron transfer (SET): A mechanism involving the transfer of one electron between species, leading to radical ion intermediates.

Heterolytic bond activation: Cleavage of a covalent bond in which both electrons are transferred to one fragment, generating ionic products.

References

1. Insights into Single-Electron-Transfer Processes in Frustrated Lewis Pair Chemistry and Related Donor–Acceptor Systems in Main Group Chemistry. Chemical Reviews (2023).
2. In-silico-assisted derivatization of triarylboranes for the catalytic reductive functionalization of aniline-derived amino acids and peptides with H2. Nature Communications (2024).
3. A unified survey of Si–H and H–H bond activation catalysed by electron-deficient boranes. Chemical Society Reviews (2015).