Recent Advances of Biphenylene: Synthesis, Reactions and Uses

Biphenylene is an antiaromatic compound that has a strained butadiene skeleton that joins two benzene rings. Various methods for synthesizing the biphenylene core have been developed. In addition, the reactivity of biphenylene has attracted much attention because C-C bonds of biphenylene can be cleaved by various organometallic species. Furthermore, the biphenylene motif not only acts as a spacer in a variety of functional molecules, but also serves as a backbone for catalysts and ligands. This minireview summarizes how to construct the biphenylene structure, how to react biphenylene, and how to use the biphenylene skeleton in functional materials.