Indium (III) mediated Markovnikov addition of malonates and β-ketoesters to terminal alkynes and the formation of Knoevenagel condensation products

The indium(III) triflate mediated addition of active methylene compounds to terminal alkynes has been expanded to use malonates and low boiling terminal alkynes to form the Markovnikov addition products. Indium(III) chloride and indium(III) bromide were also found to be efficient catalysts. Knoevenagel condensation products were isolated when reactions involved a simple malonate or β-ketoester.