Hydrophobic polymer-supported scandium catalyst for carbon–carbon bond-forming reactions in water

It has been revealed that a hydrophobic polymer-supported scandium(III) catalyst prepared from sulfonated polystyrene resin is an effective catalyst for carbon–carbon bond-forming reactions such as Mukaiyama aldol reactions in water. According to studies on loading levels of scandium, hydrophobicity of the catalyst is a key for the efficient catalysis. The scandium catalyst was successfully recovered and reused. Several ketones instead of aldehydes were also used as substrates in the aldol reactions. Some 1,4-addition reactions also occurred using the scandium catalyst in water.