Conversion of pinacol arylboronic esters 3 to aryl triolborates 5 via transesterification with 1, 1, 1-tris (hydroxymethyl) ethane (4) was established with the advantages of tolerance to various functional groups. Transesterification was carried out at 30–60° C in dioxane in the presence of MOH (M= Na and K) and H 2 O. High yields were achieved for stable aryl triolborates 5.
