Reactivity divergence in the cyclization of terminal epoxides all-carbon-tethered to indoles

Abstract

We report that indole-all-carbon-tethered, geminal disubstituted terminal epoxides exhibit tether-position-dependent divergent reactivity with overstoichiometric amount of BF3·OEt2. Specifically, indole C4-, C3-, and C2-tethered epoxides undergo different cascade reactions to deliver cyclohepta[cd]indoles, cyclopenta[b]indoles, and carbazoles, respectively, highlighting a unified yet divergent strategy for the construction of indole-fused carbocycles.