Transition-Metal-Free Borylation of Aryltriazene Mediated by BF3•OEt2

A practical and simple method for deaminoborylation of aryltriazene with bis(pinacolato)diboron has been developed that is mediated by BF3 center dot OEt2. Various arylboronic esters are prepared in moderate to good yields with this facile transition-metal-free procedure.