Syntheses, Structures, and Reactivities of N‑Heterocyclic Carbene-Coordinated Aminoborane Complexes

• Published in: Inorganic chemistry 2023-06, Vol.62 (22), p.8700-8709
• Main Authors: Ju, Ming-Yue, Fan, Zi-Heng, Ma, Yubin, Jing, Yi, Chen, Xi-Meng, Chen, Xuenian
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.3c00930

Recent research has attracted considerable attention toward N-heterocyclic carbene-coordinated boranes (NHC-borane) and their B-substituted derivatives because of their unique characteristics. In the present work, we focused on the syntheses, structures, and reactivities of such types of amine complexes, [NHC·BH2NH3]­X ((NHC = IPr (1,3-bis­(2,6-diisopropylphenyl)­imidazol-2-ylidene) and IMe (1,3-dimethylimidazol-2-ylidene); X = Cl, I, OTf). We have developed a synthetic method to access NHC·BH2NH2 through the reaction of NaH with [IPr·BH2NH3]­I, which was synthesized by the reaction of IPr·BH2I with NH3. As a Lewis base, NHC·BH2NH2 could further react with HCl or HOTf to produce the corresponding salts of [IPr·BH2NH3]+. IPr·BH2NH2BH2X (X = Cl, I) were synthesized by the reaction of HCl/I2 with IPr·BH2NH2BH3 and then converted to [IPr·BH2NH2BH2·IPr]­X (X = Cl, I) by reacting with IPr. The IMe-coordinated boranes reacted quite similarly. The preliminary results revealed that the introduction of the NHC molecule has a considerable impact on the solubility and reactivities of aminoboranes.