Photoredox catalyzed multi component synthesis of indolyl-4H-chromenes via HAT

Visible light-induced photoredox catalyzed, metal-free multicomponent reaction among salicylaldehydes, dimedone and indoles for synthesis of Indolyl-4H-chromenes has been reported. This new approach involving the use of visible light to form Indolyl-4H-chromenes through simultaneous reaction which involves C–O and C–C bonds formation with significant yield of the desired product in remarkably moderate reaction conditions. This one-pot synthetic method has many advantages, including a wide range of substrates, readily available starting materials and high efficiency.