Recently, organic reactions in water without use of harmful organic solvents have attracted much attention, because water is a cheap, safe, and environmentally benign solvent. 5 In the course of our investigations to develop new synthetic methods in water, we have recently found that a combination of a water-stable Lewis acid (eg scandium triflate) and an anionic surfactant (eg sodium dodecyl sulfate (SDS)) provides an efficient system for some Lewis acid-catalyzed ...