Gold(III) chloride (HAuCl4·3H2O) in PEG: A new and efficient catalytic system for the synthesis of functionalized spirochromenes

Gold(III) chloride (HAuCl4·3H2O) in PEG 400 was found to be an efficient catalytic system for the synthesis of biologically important functionalized spirochromene derivatives via one-pot three-component reaction of isatins/acenaphthoquinone, active methylene compounds and cyclic 1,3-diketones/4-hydroxycoumarin. A new catalytic system, recyclability of reaction medium, little reaction times and excellent yields with easy workup render this protocol more attractive and economically viable.

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► Eco-friendly method for the synthesis of functionalized spirochromenes.
► Gold(III) chloride (HAuCl4·3H2O) is used as soft carbophilic Lewis acid catalyst.
► Recyclability of polyethylene glycol (PEG).
► Multicomponent reaction.
► This protocol is green and advantageous with high yields and less reaction time.