Nothing frustrating about “Frustrated Lewis pairs”
In the six short years following our initial report, the areas impacted by the chemistry of “frustrated Lewis pairs” (FLPs) continue to grow most dramatically. The collection of papers presented in this issue of Dalton Transactions reflect the broadening impact and excitement of the new field of FLP chemistry.
Hydrogen activation by 2-boryl-N,N-dialkylanilines: a revision of Piers’ ansa-aminoborane
Two 2-[bis(pentafluorophenyl)boryl]-N,N-dialkylanilines, exemplifying a new class of intramolecular frustrated B/N Lewis pairs, can activate hydrogen at near ambient conditions; besides, one of them can hydrogenate imines and enamines in a catalytic fashion.
Asymmetric hydrogenation of imines with a recyclable chiral frustrated Lewis pair catalyst
A camphor based chiral phosphonium hydrido borate zwitterion was synthesised and successfully applied in the enantioselective hydrogenation of imines with selectivities up to 76% ee. The high stability of the novel chiral FLP-system enables effective recycling of the metal-free catalyst.
activation by a tris[3,5-bis(trifluoromethyl)phenyl]borane frustrated Lewis pair
Tris[3,5-bis(trifluoromethyl)phenyl]borane (BArF18) forms a Frustrated Lewis pair with 2,2,6,6-tetramethylpiperidine, which cleaves H2 to provide the novel bridging borohydride [μ-H(BArF18)2]−.
Association of frustrated phosphine–borane pairs in toluene: molecular dynamics simulations
Explicit solvent molecular dynamics simulations of the (tBu)3P/B(C6F5)3 pair in toluene allowed the estimation of the degree of intermolecular association and the population of encounter complex states in solution phase.
Exchange chemistry of tBu3P(CO2)B(C6F5)2Cl
Exchange reactions of tBu3P(CO2)B(C6F5)2Cl afford tBu3P(CO2)B(C6F5)2(OSO2CF3), tBu3P(CO2)Al(C6F5)3 and [tBu3P(CO2)TiCp2Cl][B(C6F5)4].
polymerization by classical and frustrated Lewis pairs: acid, base and monomer scope and polymerization mechanism
Al(C6F5)3-based classical and frustrated Lewis pairs exhibit exceptional activity in Lewis pair polymerization of conjugated polar alkenes and renewable methylene butyrolactones.
Intramolecular Lewis acid–base pairs based on 4-ethynyl-2,6-lutidine
The reaction of 4-ethynyl-2,6-lutidine, (2,6-Me2)(4-HCC)C5H2N, with the Lewis acid B(C6F5)3 leads to the zwitterion [(2,6-Me2)(4-(C6F5)3BCC)-C5H2NH], whereas its reactions with MR3 (M = Al, Ga, In; R = Me, Et) lead exclusively to metallation of the ethynyl group and the products [(2,6-Me2)(R2MCC)C5H2N].
Heterolytic addition of E–H bonds across Pt–P bonds in Pt N-heterocyclic phosphenium/phosphido complexes
The reactivity of E–H bonds (E = S, O, Cl) with Pt(II) complexes ligated by an N-heterocyclic phosphido-containing diphosphine ligand have been investigated.
Theoretical analysis of cooperative effects of small molecule
activation by frustrated Lewis pairs
The cooperative nature of small molecule activation with FLPs is analysed in terms of many-body contributions to energy and deformation density.
Synthesis and reactivity of electron poor allenes: formation of completely organic frustrated Lewis pairs
The synthesis of several electron poor allenes is described and their application as Lewis acids for the formation of organic frustrated Lewis pairs evaluated.
Frustrated Lewis pair addition to conjugated diynes: Formation of zwitterionic 1,2,3-butatriene derivatives
The frustrated Lewis pair B(C6F5)3/PtBu3 reacts with 2,4-hexadiyne to give mixture of the 1,2- and 1,4-addition products.
Catalytic metal-free intramolecular hydroaminations of non-activated aminoalkenes: A computational exploration
Computations show the promise of using the previously designed catalysts to promote intramolecular hydroaminations of non-activated aminoalkenes affording nitrogen heterocycles.
Fixation of carbon dioxide and related small molecules by a bifunctional frustrated pyrazolylborane Lewis pair
The fixation of carbon dioxide and related small molecules is efficiently accomplished by a bifunctional frustrated pyrazolylborane Lewis pair; CO2 fixation presumably proceeds via a van der Waals complex with a low energy barrier of approximately 7.2 kcal mol−1.
Computational studies of complexation of nitrous oxide by borane–phosphine frustrated Lewis pairs
Several interesting facets of FLP–N2O complexes were investigated computationally, including the preference for the BONNP core and the trans–trans structure, borane exchange reactions, and possibilities for N2O derivatization.
Heterolytic activation of hydrogen using frustrated Lewis pairs containing tris(2,2′,2′′-perfluorobiphenyl)borane
The bulky borane tris(2,2,2-perfluorobiphenyl)borane is crystallographically characterised, and is used with nitrogen based Lewis bases to synthesize novel ‘frustrated Lewis pairs’ that activate dihydrogen.
[2.2]Paracyclophane derived bisphosphines for the activation of hydrogen by FLPs: application in domino hydrosilylation/hydrogenation of enones
The heterolytic splitting of hydrogen by two types of [2.2]paracyclophane derived bisphosphines (1, 2a and 2b) in combination with tris(pentafluorophenyl)borane (3) at room temperature is described.
Cationic Ti(IV) and neutral Ti(III) titanocene–phosphinoaryloxide frustrated Lewis pairs: hydrogen activation and catalytic amine-borane dehydrogenation
Titanium–phosphorus frustrated Lewis pairs (FLPs) based on titanocene–phosphinoaryloxide complexes have been studied..
Dimeric aluminum–phosphorus compounds as masked frustrated Lewis pairs for small molecule activation
Al–P-based dimers with coordinatively saturated Al and P atoms act as masked frustrated Lewis pairs by dipolar activation of CO2 and phenyl isocyanate.
About this collection
This themed issue reflects the broadening impact and excitement of the new field of FLP chemistry.