School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 P. R. China.; Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen 518055 P. R. China ; School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059 P. R. China ; State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071 P. R. China
Abstract:
A cationic terminal iminoborane [Mes*N B ← IPr2Me2][AlBr4] (3+[AlBr4]−) (Mes* = 2,4,6-tri-tert-butylphenyl and IPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) has been synthesized and characterized. The employment of an aryl group and N-heterocyclic carbene (NHC) ligand enables 3+[AlBr4]− to exhibit both B-centered Lewis acidity and BN multiple bond reactivities, thus allowing for the construction of tri-coordinate boron cations 5+–12+. More importantly, initial reactions involving coordination, addition, and [2 + 3] cycloadditions have been observed for the cationic iminoborane, demonstrating the potential to build numerous organoboron species via several synthetic routes.An NHC-stabilized aryliminoboryl cation exhibits both boron-centered Lewis acidity and multiple bond reactivity and could be utilized as an effective synthon for unusual cationic boron species.
