Regioselective Cycloaddition and Substitution Reaction of Tertiary Propargylic Alcohols and Heteroareneboronic Acids via Acid Catalysis

Org Lett. 2022 Jul 1;24(25):4507-4512. doi: 10.1021/acs.orglett.2c01403. Epub 2022 Jun 15.

Abstract

We report an acid-catalyzed formal cycloaddition and dehydrative substitution reaction of tertiary propargylic alcohols and heteroareneboronic acids. The properties of the substituents on the alkynyl moiety determines the regioselectivity of the reaction, which could selectively construct fused heterocycles, tetrasubstituted allenes, or 1,3-dienes. This reaction proceeds efficiently with a wide array of substrate scope in up to 89% yield. A significant advantage of this protocol is the transition-metal-free and mild conditions needed.