Regioselective Synthesis of Phenols and Halophenols from Arylboronic Acids Using Solid Poly(N-vinylpyrrolidone)/Hydrogen Peroxide and Poly(4-vinylpyridine)/Hydrogen Peroxide Complexes

摘要

Solid hydrogen peroxide complexes based on poly(N-vmyipyrrolidone) and poly(4-vinylpyri-dine) were prepared and used as solid hydroxylating reagents. These solid hydrogen peroxide equivalents are found to be much safer, convenient and efficient reagent systems for the ipso-hydroxylation of arylboronic acids to the corresponding phenols in high yields at a faster rate. The versatility of the reagents has been further expanded for the one-pot synthesis of halophenols. Density functional theory calcula- tions were carried out on hydrogen peroxide complexes of N-ethylpyrrolidone and 4-ethylpyridine as models to get a better understanding of structure and behavior of hydrogen peroxide complexes of the polymers poly(N-vinylpyrrolidone) and poly(4-vinyl-pyridine) compared to aqueous hydrogen peroxide.