Phosphorous Acid Promoted Hydration–Condensation of Aromatic Alkynes with Aldehydes Affording Chalcones in an Oil/Water Two-Phase System

A simple and environmentally benign method was developed for the synthesis of chalcones in high to excellent yields by a phosphorous acid promoted alkyne–aldehyde hydration–condensation in an oil/water two-phase system. The method is the first efficient protocol for the preparation of chalcones that is mediated by a simple Brønsted acid in a two-phase system.