N‐Heterocyclic Carbene Derived 3‐Azabutadiene as a π‐Base in Classic and Frustrated Lewis Pair Chemistry

N‐Heterocyclic carbene (NHC) derived 3‐azabutadienes 1 and 2 have been prepared by a single‐step reaction of the corresponding NHC with cyclohexyl isocyanide. Compound 1 features π‐basic, delocalized nucleophilic sites over the 3‐azabutadiene moiety, therefore allowing for coordinating with small Lewis acids, such as AlCl 3 , GaCl 3 , and Me 2 SAuCl, to form diverse classic Lewis adducts 3 – 5 . Combination of 1 with B(C 6 F 5 ) 3 or [Ph 3 C][B(C 6 F 5 ) 4 ] resulted in single‐electron transfer and the obtained radical cation was detected by EPR. In addition, a frustrated Lewis pair comprised of the π‐basic 1 and BPh 3 effects the splitting of the O−H bond of phenol and the N−H bond of imidazole to give 7 and 8 , respectively. An intrinsic bond orbital (IBO) analysis of the pathway leading to 8 showcases the transformation of the delocalized π‐electrons of 1 to a newly formed C−H localized σ‐bond.