Strain-release difunctionalization of CC σ- And π-bonds of an Organoboron Ate-complex through 1,2-Metallate Rearrangement

This highlight review describes the recent development of an electrophile-triggered 1,2-metallate rearrangement of organoboronic ester ate-complex, which proceeds through 1,2-difunctionalization of carboncarbon σ- and π-bonds, using strain energy as a driving force. Coupling reactions of small ring carbocyclic boronic esters, such as cyclopropyl-, bicyclo[1.1.0]- butyl-, and cyclopropenyl-boronic ester, are summarized along with the proposed reaction mechanisms and representative examples.