Base-Stabilized Neutral Oxoborane and Thioxoborane Supported by a Bis(oxazolinyl)(phenyl)methanide Ligand.

Base-stabilized neutral oxoborane and thioxoborane supported by a bis(oxazolinyl)(phenyl)methanide ligand have been synthesized and structurally characterized. While previous synthetic attempts of oxoborane ligated by β-diketiminate (NacNac) did not allow for its isolation in acid-free form, oxoborane supported by a bis(oxazolinyl)(phenyl)methanide ligand is isolable, due to the absence of imine ɑ-protons and steric protection of enamine carbon. Crystallographic analysis revealed the presence of a B-O double bond close to the shortest end of the reported lengths. Its reactivity has also been examined, and it was majorly governed by the nucleophilicity and basicity of the oxygen atom. The chemical inertness and synthetic convenience of the bis(oxazolinyl)(phenyl)methanide scaffold presented in this work suggest its utility as an innocent alternative to the NacNac scaffold.