Substrate-Controlled Generation of 3‑Sulfonylated 1‑Indenones and 3‑Arylated (Z)‑Indenes via Cu-Catalyzed Radical Cyclization Cascades of o‑Alkynylbenzonitriles

Substrate-controlled generation of 3-sulfonylated 1-indenones and 3-arylated (Z)-indenes through radical cyclization cascades of o-alkynylbenzonitriles with sulfonyl hydrazides was established by combining copper­(II) with tert-butyl hydroperoxide (TBHP) as a catalytic oxidative system. With the installation of the aryl group (R1) into the alkynyl unit, sulfonyl radicals triggered addition–cyclization cascades to access 3-sulfonylated 1-indenones with good yields by using a Cu/TBHP system, whereas a series of new functionalized 3-arylated (Z)-indenes were obtained in good yields when o-alkynylbenzonitriles bearing the alkyl group in the alkynyl unit were subjected with arylsulfonyl hydrazides with an electron-rich nature under the above conditions.