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.

本研究开发了一种高效的铜催化自由基级联环化策略。通过该策略，可在温和反应条件下，以2-炔基苯甲腈与磺酰肼为底物，在叔丁基过氧化氢(TBHP)与碘化亚铜(CuI)的存在下，经一锅反应制备多种3-磺酰基取代茚酮类化合物。尤为重要的是，通过本策略合成的3-磺酰基茚酮具有典型的聚集诱导发光(aggregation-induced emission, AIE)特性，可发射橙红色荧光，且斯托克斯位移大于135 nm。此外，这类新发现的AIE发光分子可成功应用于活细胞成像，展现出优异的生物相容性与应用潜力。