Regioselectivity-Switchable Catalytic Annulations of Alkynyl α-Diketones and α-Cyanoketones

Org Lett. 2019 Dec 20;21(24):10075-10080. doi: 10.1021/acs.orglett.9b04040. Epub 2019 Dec 3.

Abstract

Regioselectivity-switchable reactions hold irreplaceable importance in the construction of diversified architectures. In this work, Brønsted base-catalyzed regioselectivity-switchable annulations between alkynyl α-diketones and α-cyanoketones have been achieved for the first time, delivering a series of skeletally thoroughly different dihydrofurofuran and furan derivatives. A range of novel transformations of the products can be realized. The work also demonstrates the unique features of alkynyl α-diketone chemistry, which are in sharp contrast to the current understanding of ynone-related chemistry.