Relative Cycloaddition Rates of Alkyne-Equivalent Dienophiles

Alkyne-equivalent dienophiles are strategically important coupling partners in Diels-Alder reactions. They are particularly useful in cascade bond-forming processes that begin with cycloadditions. A systematic rate study for the cycloaddition of several alkyne and alkyne-equivalent dienophiles is presented, showing that the relative reaction rates of these dienophiles vary over multiple orders of magnitude.