Transition metal-free oxidative and deoxygenative C–H/C–Li cross-couplings of 2H-imidazole 1-oxides with carboranyl lithium as an efficient synthetic approach to azaheterocyclic carboranes

• Lidia A. Smyshliaeva,
• Mikhail V. Varaksin,
• Pavel A. Slepukhin,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2018, 14, 2618–2626, doi:10.3762/bjoc.14.240

• 1-oxide; nucleophilic substitution of hydrogen (SNH); Introduction Dicarbadodecaboranes (carboranes) are known to be 3D polyhedral clusters with a special type of structural organization, relative thermal and chemical stabilities, as well as unique physicochemical properties [1][2][3]. The

• considered as nucleophilic substitution of hydrogen (SNH) in non-aromatic N-oxides of 2H-imidazoles 1a–d. It has also been shown that the SNH reactions can be realized via either an "addition–elimination" SNH(AE) mechanism, or through an "addition–oxidation" SNH(AO) scheme to form imidazolyl carbonanes 4a–d

• functionalization methodology has first been applied to design the synthesis of polyhedral boron closo-clusters. Novel heterocyclic carboranes have been obtained through a one pot-, atom- and stage-economical approach, based on nucleophilic substitution of hydrogen (SNH) in 2H-imidazole 1-oxides by action of