Copper-Catalyzed Radical Cascade Cyclization To Access 3‑Sulfonated Indenones with the AIE Phenomenon

An
efficient copper-catalyzed radical cascade cyclization strategy
was developed, by which a wide variety of 3-sulfonyl substituted indenones
were prepared in one pot via reaction of 2-alkynylbenzonitriles with
sulfonyl hydrazides in the presence of TBHP and CuI under mild reaction
conditions. Much more importantly, the 3-sulfonyl indenones, synthesized
through our newly developed copper-catalyzed radical cascade cyclization
strategy, were found to own typical aggregation-induced emission (AIE)
properties, showing orange to red emission with large Stokes shift
(more than 135 nm). In addition, such newly found AIEgens could be
successfully used in live cell imaging, exhibiting excellent biocompatibility
and application potential.