Copper(I)-catalyzed electrophilic thiocyanation/dearomatization/spirocyclization of benzofurans to synthesize benzannulated spiroketals

Org Biomol Chem. 2023 May 24;21(20):4216-4219. doi: 10.1039/d3ob00438d.

Abstract

A Lewis acid-catalyzed electrophilic dearomatizative thiocyanation and cyclization of benzofurans with N-thiocyanatosuccinimide has been accomplished by Lewis acid catalysis with CuOTf under mild conditions. It was suggested that the electrophilic thiocyanating reagent was activated by CuOTf, and difunctionalization was achieved through a thiocyanation/spirocyclization pathway. Thus, a series of thiocyanato-containing spiroketals were obtained in moderate to high yields. It provides an alternative approach for the synthesis of functionalized [6,5]/[5,5]-spiroketals.