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通过固相合成的方法将聚酰胺-胺树状大分子PAMAM担载于大孔硅胶上,并对其外围分别用对羟基苯甲醛、2,4-二羟基苯甲醛和邻羟基苯甲醛进行修饰,再与SnCl2.2H2O反应形成三类共计9种不同代数树状高分子锡配合物。将该类配合物用作质量分数30%双氧水氧化酮的Baeyer-Villiger(B-V)反应的催化剂,考察其催化活性,结果表明,在该类配合物作用下,2-金刚烷酮、环戊酮、环己酮、4-甲基环己酮、4-叔丁基环己酮、3-甲基-2-戊酮和4-甲基-2-戊酮都可以发生B-V氧化反应而转化为相应的酯和内酯,底物的转化率(75%～99%)和产物选择性(95%～100%)都较高。比较了不同载体(氯球、纤维素、壳聚糖、硅胶)、不同配体的金属锡配合物对B-V催氧化反应的催化效果,研究发现,载体、配体和金属担载量对配合物的催化活性均有不同程度的影响。其中,硅胶为最好的载体,而邻羟基苯甲醛为最好的配体。
Polyamidoamine dendrimer PAMAM was supported on macroporous silica gel by solid-phase synthesis, and its periphery was modified with p-hydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde and o-hydroxybenzaldehyde respectively , And then reacted with SnCl2.2H2O to form three kinds of altogether 9 kinds of algebra dendrimer complexes. The complex was used as a catalyst for the Baeyer-Villiger (BV) reaction of 30% H2O2. The catalytic activity of Baeyer-Villiger reaction was investigated. The results showed that under the action of these complexes, , Cyclohexanone, 4-methylcyclohexanone, 4-tert-butylcyclohexanone, 3-methyl-2-pentanone and 4-methyl-2-pentanone can all undergo BV oxidation to convert to the corresponding Ester and lactone, the substrate conversion (75% ~ 99%) and product selectivity (95% ~ 100%) are higher. The catalytic effect of metal-tin complexes with different carriers (chlorine, cellulose, chitosan, silica gel) and different ligands on the catalytic oxidation of BV was studied. The results showed that the loading of support, ligand and metal The catalytic activity has varying degrees of impact. Among them, silica gel is the best carrier, while o-hydroxybenzaldehyde is the best ligand.