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Reactivity of a Frustrated Lewis Pair and Small‐Molecule Activation by an Isolable Arduengo CarbeneB{3,5‐(CF 3 ) 2 C 6 H 3 } 3 Complex
Author(s) -
Kolychev Eugene L.,
Bannenberg Thomas,
Freytag Matthias,
Daniliuc Constantin G.,
Jones Peter G.,
Tamm Matthias
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201202840
Subject(s) - carbene , reactivity (psychology) , frustrated lewis pair , molecule , physics , chemistry , crystallography , stereochemistry , lewis acids and bases , catalysis , organic chemistry , medicine , alternative medicine , pathology
Tris[3,5‐bis(trifluoromethyl)phenyl]borane reacts with the sterically demanding Arduengo carbenes 1,3‐di‐ tert ‐butylimidazolin‐2‐ylidene and 1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene to form isolable normal adducts. In the case of 1,3‐di‐ tert ‐butylimidazolin‐2‐ylidene, the adduct exhibits dynamic behaviour in solution and frustrated‐Lewis‐pair (FLP) reactivity. Fast cleavage of dihydrogen and THF, the CH activation of phenylacetylene, and carbon dioxide fixation were achieved by using solutions of this adduct in benzene. This adduct is stable at room temperature in the absence of suitable substrates; however, thermal rearrangement into an abnormal carbene–borane adduct can be observed. In contrast, the 1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene adduct exhibits no evidence of FLP reactivity or of dissociation in solution. DFT calculations confirmed the experimental behaviour and stability of these carbene–borane adducts.