Construction of σ-aromatic AlB₂ ring via borane coupling with a dicoordinate cyclic (alkyl)(amino)aluminyl anion

• Main Authors: Koshino, Kota, Kinjo, Rei
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2021
• Subjects: Science::Chemistry; Anions; Reaction Products
• Online Access: https://hdl.handle.net/10356/151894
• Institution: Nanyang Technological University

Since the groundbreaking discovery in 2018 that the synthesis of a bottleable nucleophilic aluminyl anion is feasible, a handful of derivatives have been developed to date, which are, however, limited to diamino- and dialkyl-substituted species. Herein, we report the synthesis of a cyclic (alkyl)(amino)aluminyl anion based on a five-membered framework. The dicoordinate aluminum center features both a lone pair of electrons and an unoccupied 3p orbital, thus genuinely making it isoelectronic with carbenes. We show the bond formation and bond activation at the Al sphere: thus, not only does it undergo electron redistribution with borane to furnish a heteroatomic group 13 ring exhibiting a σ-aromatic nature concomitant with a three-center two-electron AlB₂ bond but also the ambiphilic nature allows for oxidative addition of Si-H, N-H, and even C-C bonds at the aluminum center.