Frustrated Lewis Pairs: Discovery and Overviews in Catalysis

Abstract

Frustrated Lewis Pairs (FLPs) are derived from simple combinations of Lewis acids (electron acceptors) and Lewis bases (electron donors), in which steric demands prevent from forming classical Lewis acid-base adducts. Since 2006, FLP chemistry has emerged as a novel strategy for the design and application of main-group chemistry and development of new metal-free catalytic processes. This strategy has been applied to stoichiometric reactivity and then extended to catalysis. In this review, we briefly summarize the representative discoveries and developments of FLP chemistry in the field of catalysis, including hydrogenation, hydrosilylation, reduction of CO2, transformations of alkynes to organic derivatives, C-H bond borylation and polymerization. Nan Li (left) was born in Henan, China, in 1988. She received her BS degree from Xinyang University in 2012. She obtained her PhD degree in 2017, supervised by Professor Bing-Tao Guan at Nankai University. Following her graduate research, she moved to the college of chemistry at Peking University as a Postdoctoral Fellow in the laboratory of Professor Zhenfeng Xi and Professor Wen-Xiong Zhang (2017-2019). Wen-Xiong Zhang (right) received his B.Sc. from Hunan Normal University in 1996, his MSc from Guangxi Normal University in 1999, and his PhD from Nankai University with professor Li-Cheng Song in 2003. He carried out postdoctoral research at Peking University with Prof. Zhenfeng Xi and at Riken in Japan with Prof. Zhaomin Hou. In 2007, he joined College of Chemistry at Peking University as an Associate Professor, where he is now a Professor. His research interests include design, synthesis and small molecule activation of rare-earth-metal heterocycles, metal-catalyzed C-N bond activation, and carbodiimide-based organic synthesis to construct N-containing heterocycles.

Phosphorus-Based Catalysis

“…Today, phosphorus-based Brønsted acid catalysis remains an active area of inquiry. Finally, FLPs, formed from combinations of Lewis acids and Lewis bases, have been used in the development of main group element catalysis processes for the activation of small molecules (e.g., H 2 , CO 2 , CO, SO 2 ) . In this context, various phosphines have played important roles in combination with Lewis acids [e.g., B­(C 6 F 5 ) 3 and Al­(C 6 F 5 ) 3 ] to form active FLPs .…”

“…For example, chiral phosphoric acid catalysis and phosphine oxide Lewis base catalysis play important roles in asymmetric organocatalysis. Frustrated Lewis pairs (FLPs), combinations of Lewis acids and Lewis bases, are important species for the activation of small molecules . As a green sustainable tool in organic synthesis, phosphonium salt-based phase transfer catalysis is garnering increasing attention .…”

Proton-phosphorous connectivities revealed by high-resolution proton-detected solid-state NMR

“…The discovery of Frustrated Lewis Pairs (FLPs) and their investigation in a variety of reaction pathways was a milestone of main group chemistry in the past years and is still of high interest. [18][19][20][21][22][23][24][25][26][27] This is particularly associated with their capabilities in activating and binding small molecules, with dihydrogen being probably the most important example. 22,[28][29][30][31][32] Structural characterization is typically performed by X-ray diffraction and solution-state NMR, although also the benefit of solid-state NMR has been reported, 15,[33][34][35][36][37] in particular for oligomeric systems.…”

Nickel-Catalyzed Diversification of Phosphine Ligands by Formal Substitution at Phosphorus

“…Taking advantage of a versatile toolbox of synthetic methods to access phosphines, [4] many powerful phosphine ligand architectures have been developed. [5][6][7][8][9][10][11] Phosphines have also been employed in numerous other applications such as organocatalysis, [12,13] frustrated Lewis pair catalysis, [14,15] or material sciences. [16,17] It can be expected that the continued design of phosphines will lead to even more active ligands, opening further avenues for the application of this intriguing class of compounds.…”