d or the pinacol ester of said boronic acids or an aryltrialkylstannane or a heteroaryltrialkylstannane, in a solvent, such as toluene or tetrahydrofuran or n-butanol or 1,4-dioxane or 1,2-dimethoxyethane or a mixture of solvents, such as tetrahydrofuran and methanol, at an elevated temperature, such as 200??? C. or 120??? C. or 80??? C., achieved by either conventional or microwave heating, optio