Mesoporous nickel hydroxyapatite nanocomposite for microwave-assisted Henry reaction

A new cyclic binuclear Ni(II) complex as a catalyst towards nitroaldol (Henry) reaction

“…A maximum of 71% conversion was obtained in the case of propionaldehyde (entry 7) with a syn : anti ratio of 71:29. In comparison with other heterogeneous nickel catalysts (Table 3), our system, with the advantage of using water, leads to yields that are similar to those reported for heterogeneous Ni-Al (Ni:Al=3:1) hydrotalcites when using ionic liquids [24] or for Nihydroxyapatite under microwave irradiation to promote the reaction [16]. Since recycling of a catalyst is one of the most significant advantages of heterogeneous catalysis, we checked the reusability of 1 up to three cycles ( Table 4).…”

“…The stereoselectivity of the reaction was first time reported by Shibasaki in 1992 [11] and a number of works have appeared in recent years [3][4][5][6], showing the current interest of the Henry reaction and its application. The reaction has been studied in homogeneous [3][4][5][6], heterogeneous [12][13][14], ionic liquids or supercritical fluids [15], mesoporous nanocomposite conditions [16], etc. However, the achievement of a good selectivity is still a challenge, and it is also important the search for new catalysts which can be prepared easily and are commercially cheap.…”

“…Some nickel compounds can also act as catalysts towards the Henry reaction under different conditions, namely in homogeneous systems [23], under solvent free microwave conditions [16] or in ionic liquids [24], and high activities (more than 90% yields) are found in a few cases [16,24].…”

Can Ultrasound or pH Influence Pd Distribution on the Surface of HAP to Improve Its Catalytic Properties in the Dry Reforming of Methane?

“…It has a hexagonal crystal structure with the P6 3 /m space group and well-known 1.67 Ca:P ratio [26]. The introduction of metal to HAP is crucial towards its catalytic activity, as described widely in the literature [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Boukha et al recently reported Pd doped HAP for CO elimination processes and 1 3 investigated the influence of Pd particle size, with different metal loadings on the activity and selectivity towards CO oxidation.…”

Henry reaction catalyzed by Lipase A fromAspergillus niger

“…Since Henry reaction was reported in 1895 (18), various catalysts have been employed to perform the Henry reaction, including rare earth metal complexes, chiral metal catalysts, organocatalysts, and so on (5, 19Á23). For example, some Henry reactions catalyzed by strong bases have been successful reported in good yields, but a great many of useless side products were produced in such processes (6,24). Therefore, it is necessary to develop green and efficient catalysts for Henry reaction.…”