A TBADT-enabled photo-induced radical cyclization pathway: concise access to functionalized oxindoles

Abstract

Herein, this work describes a mild and general protocol for photo-induced cascade cyclisation of arylalkynamides resulting in diversely functionalized oxindoles. This strategy enables the construction of two C–C bonds through a radical cascade process via a hydrogen atom transfer pathway employing the decatungstate anion ([W₁₀O₃₂]⁴⁻) as an efficient HAT photocatalyst. Interestingly, pivaldehyde afforded unexpected Z-indolinones stereospecifically in our strategy.