The First Boron-Tellurium Double Bond: Direct Insertion of Heavy Chalcogens into a Mn=B Double Bond.

The base-stabilized borylene [Cp(OC)2 Mn=BtBu(IMe)] readily reacts with elemental chalcogens in an insertion reaction that yields borachalcone complexes [Cp(OC)2 Mn-E=BtBu(IMe)] (E=S, Se, Te). The tellurium example features the first double bond between boron and tellurium, making Te the heaviest main-group element to make multiple bonds with boron. This unprecedented interaction has been fully investigated both experimentally and computationally.