One-step synthesis of tetrahydroindoles by ceric(IV) ammonium nitrate-promoted oxidative cycloaddition of enaminones and vinyl ethers

A new and general one-step procedure to synthesize a variety of biologically interesting tetrahydroindole derivatives was successfully devised by reacting various β-enaminones with vinyl ethers in the presence of ceric(IV) ammonium nitrate as promoter. This novel synthetic method provides a facile and promising strategy to various tetrahydroindole derivatives in moderate to good yields.