Regioselective allenylation and propargylation of various para-quinone methides using alkynyl azaarenes as pronucleophiles

Abstract

We have developed Brønsted base-mediated regioselective allenylation and propargylation of various para-quinone methides using unfunctionalized 2-alkynyl azaarenes as pronucleophiles. The appropriate choice of a base provides an opportunity to achieve either an allenylated product or the propargylated product. The use of KO^tBu as a Brønsted base promotes the formation of allenylated products, whereas NaN(SiMe₃)₂ furnishes the propargylated products. Besides, the current strategy is scalable and can be performed on a gram scale.