A frustrated Lewis pair (FLP) is a compound or mixture containing a Lewis acid and a Lewis base that, because of steric hindrance, cannot combine to form a classical adduct.[1] Many kinds of FLPs have been devised, and many simple substrates exhibit activation.[2][3]
The discovery that some FLPs split H2[4] triggered a rapid growth of research into FLPs. Because of their "unquenched" reactivity, such systems are reactive toward substrates that can undergo heterolysis. For example, many FLPs split hydrogen molecules. Thus, a mixture of tricyclohexylphosphine (PCy3) and tris(pentafluorophenyl)borane reacts with hydrogen to give the respective phosphonium and borate ions:
- PCy3 + B(C6F5)3 + H2 → [HPCy3]+ [HB(C6F5)3]−
This reactivity has been exploited to produce FLPs which catalyse hydrogenation reactions.[5]
- ^ Stephan, Douglas W (2008). "Frustrated Lewis pairs: a concept for new reactivity and catalysis". Org. Biomol. Chem. 6 (9): 1535–1539. doi:10.1039/b802575b. PMID 18421382.
- ^ Stephan, Douglas W.; Erker, Gerhard (2010). "Frustrated Lewis Pairs: Metal-free Hydrogen Activation and More". Angewandte Chemie International Edition. 49 (1): 46–76. doi:10.1002/anie.200903708. ISSN 1433-7851. PMID 20025001.
- ^ Stephan, Douglas W.; Erker, Gerhard (2017). "Frustrated Lewis pair chemistry". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 375 (2101): 20170239. Bibcode:2017RSPTA.37570239S. doi:10.1098/rsta.2017.0239. ISSN 1364-503X. PMC 5540845. PMID 28739971.
- ^ Welch, Gregory C.; Juan, Ronan R. San; Masuda, Jason D.; Stephan, Douglas W. (2006). "Reversible, Metal-Free Hydrogen Activation". Science. 314 (5802): 1124–1126. Bibcode:2006Sci...314.1124W. doi:10.1126/science.1134230. ISSN 0036-8075. PMID 17110572. S2CID 20333088.
- ^ Lam, Jolie; Szkop, Kevin M.; Mosaferi, Eliar; Stephan, Douglas W. (2018). "FLP catalysis: main group hydrogenations of organic unsaturated substrates". Chemical Society Reviews. 41 (13): 3592–3612. doi:10.1039/C8CS00277K. PMID 30178796. S2CID 206130644.
