Nucleophilic Diboration Strategy Targeting Diversified 1‐Boraphenarene Architectures

Abstract

Abstract1‐Boraphenalenes, a class of boron‐doped polyaromatic hydrocarbons, were synthesized by nucleophilic diboration reaction of alkynes. Activation of diboron reagents with a highly basic sp2‐carbanion results in very fast successive C−B bond formations to construct the boracycle. This methodology is characterized by high chemoselectivity, affording a wide variety of 1‐boraphenarenes with diverse polar substituents. The endocyclic boron can be arylated conveniently in one pot, and the peripheral boron is available for various chemical transformations. Highly diastereoselective diboration gives pseudo‐enantio‐enriched boraphenarene, which emits circularly polarized fluorescence (CPL).