Abstract The radical reaction of benzenethiol with alkynes 1a-o carried out at 154 °C affords a mixture of thiol/alkyne adduct 3 and benzothiophene 5, deriving from vinyl radical intermediates 2 through hydrogen abstraction and 5-(π-endo)orthocyclization onto the adjacent thiophenyl ring, respectively. This latter reaction occurs through the reversible formation of cyclohexadienyl radical intermediates
Substrate-Controlled Generation of 3-Sulfonylated 1-Indenones and 3-Arylated (<i>Z</i>)-Indenes via Cu-Catalyzed Radical Cyclization Cascades of <i>o</i>-Alkynylbenzonitriles
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
The α-/β-C−H functionalization of E styrenes with simple alkenes and alkynes is presented. The process involves α C−H functionalization via a six-membered exo-palladacycle to afford tri- and tetrasubstituted 1,3-dienes and β C−H functionalization via a seven-membered endo-palladacycle to produce tetra- and pentasubstituted 1,3,5-trienes, both enabled by the chelation assistance of pyrazinamide.