Sequential C–H and C–C Bond Cleavage: Divergent Constructions of Fused <i>N</i>-Heterocycles via Tunable Cascade

Abstract

Streamlining the generation of diverse highly functionalized molecules from abundant feedstocks holds great synthetic promises and challenges in pharmaceutical and material discovery. Herein, we report a tunable selectivity in multiple cascade reactions for the divergent assembly of fused N-heterocycles, comprising sequential activation of C–H and C–C bonds. Isolatable indene-type intermediates might be responsible for the generation of densely substituted fused pyridines, azepines, and azafluorenones products. The tolerance of strongly coordinating N-heterocycles, and those readily applicable for the late-stage modifications of pharmaceuticals and material molecules precursors, further demonstrated the synthetic robustness of this transformation.