The Improved para-Selective C(sp(2))-H Borylation of Anisole Derivatives Enabled by Bulky Lewis Acid

An improved para-selective C(sp(2))-H borylation of anisole derivatives is described. The selective borylation is probably dominated by the change in electron density on the aromatic ring when a Lewis acid is coordinated with an anisole substrate. In addition, a sterically hindered bipyridyl ligand used in the reaction also favors para-selectivity. With this strategy, it has been demonstrated that the ratio of para-borylated products could be dramatically improved. The reaction proceeds at a milder temperature, and most substrates display moderate to good site-selectivity.

Automated summary

This article describes an improved para-selective C(sp(2))-H borylation of anisole derivatives. The selective borylation is likely to be influenced by the change in electron density on the aromatic ring when a Lewis acid coordinates with an anisole substrate. In addition, the use of a sterically hindered bipyridyl ligand in the reaction also promotes para-selectivity. This strategy has demonstrated a significant improvement in the ratio of para-borylated products, with the reaction taking place at milder temperatures and most substrates displaying moderate to good site-selectivity.