Synthesis of spiroindolone scaffolds by Pictet-Spengler spirocyclisation using β-cyclodextrin-SO3H as a recyclable catalyst

A recyclable catalyst, β-cyclodextrin-SO3H in aqueous medium was used effectively for the synthesis of spiroindolones (tetrahydrospiro-β-carbolines as well as tetrahydrospiro-γ-carbolines) in a Pictet-Spengler spirocyclisation. The products were obtained in good yield in an environmental friendly procedure.

Using a recyclable catalyst, β-cyclodextrin-SO3H in aqueous medium in a Pictet-Spengler spirocyclisation, the synthesis of spiroindolones (tetrahydrospiro-β-carbolines as well as tetrahydrospiro-γ-carbolines) was demonstrated. The products were obtained in good yield in an environmental friendly procedure.136