Initially, the effects of catalyst amount and solvent were examined. The results are summarised in Table 1. Acetophe- none was selected as a model reactant for this study. We found that treating acetophenone (10 mmol) and SeO2 (20 mmol) in a solution of dioxane/H2O (3/1, 4 mL) with A-26 (1g) as catalyst at 90 °C for 24 h gave the product in 95% yield (Table 1, entry 1). Under similar conditions, lower product yields of 88% and 73% were obtained when decreasing ...
