1,3-Dioxole derivatives were synthesized from copper(II)-catalyzed cyclization reactions of carbonyl ylides derived from 3-methylenebicyclo[2.2.1]heptan-2-one and dimethyl diazomalonate. The reaction mechanisms leading to all possible products have been extensively investigated by density functional theory. The generally accepted mechanism proposed by Doyle12 for the carbene transformation reactions were applied to this system for the first time to shed light on the reaction mechanism and to understand the catalytic activity of Cu(acac)2. Calculations have shown that the reaction mechanisms leading to different products greatly depend on the conformations of copper-stabilized carbonyl ylides, which are treated as reactants in our calculations. The conformational effects and donor−acceptor type stabilizations between the catalyst and the carbonyl ylide observed in the reactants and the transition state geometries seem to be the main reasons for the observed product selectivity. Our theoretical results are in good agreement with the experimental results, and the calculations successfully predict the experimental 75:25 product distribution.

After biological treatment, pulp and paper mill effluent still may contain large amounts of recalcitrant organic pollutants that need to be further treated. In this study, Fe supported on activated carbon (Fe@AC) was prepared and used as a catalyst in the catalytic ozonation of pulp and paper mill effluent. The activity of this catalyst was studied in terms of color and chemical oxygen demand (COD) removal efficiencies. Results showed that the COD removal rate was increased by 21% in the presence of the Fe@AC catalyst. After 60 min of ozonation (3g/h ozone flow rate) of the pulp and paper mill effluent (initial COD 360 mg/L), COD removal rates reached 56% in the presence of Fe@AC, 43% using AC as catalyst, and only 35% with ozonation alone. Ozone alone can achieve satisfactory color removal results. Owing to the scavenging effect of carbonate and bicarbonate ions towards hydroxyl radicals, the COD removal rate in Fe/AC catalytic ozonation of the effluent was strongly inhibited in the presence of these two ions. The COD removal rate followed the pseudo-second-order kinetics model well. The COD removal rate constant in the Fe@AC/O3 process was about 1.6 times higher than that of the AC/O3 process, and approximately 2.1 times higher than that of ozone alone.