Syntheses of diphenylmethane derivatives on solid acid catalysts with controlled hydrophobicity, acidity, and reaction space

从绿色化学的角度看，均相催化合成化学品中的催化剂多相化是一个重要的问题。本研究的目的是为以下三个反应寻找合适的固体酸催化剂，并在实际过程中使用均相催化剂：(1)甲醛和苯酚合成双酚F，(2)甲醛和2,6 -二甲基苯酚合成双（4-羟基- 3,5 -二甲基苯基）甲烷，(3)甲醛和苯胺合成双（4-氨基苯基）甲烷。所测试的催化剂是各种类型的沸石分子筛和介孔铝硅酸盐分子筛（Al-MCM-41）。所有的反应都在常压下的液相中进行。以商品苯酚、2,6 -二甲基苯酚、苯胺和福尔马林为反应物，未经纯化。本研究表明，由于甲醛的高反应活性，弱酸位点负责三个反应，并且每个反应的催化剂和反应条件都是合适的。即，反应(1)的适宜催化剂为高硅h - β沸石和Al-MCM-41，且需要高酚甲醛比才能获得高选择性；反应(2)的适宜催化剂为Al-MCM-41，在任何配比下选择性都接近100%；反应(3)的活性催化剂为Al-MCM-41、h - β和USY沸石，选择性受反应空间影响，USY表现出最高的选择性。

Catalyst heterogenization in syntheses of chemicals by homogeneous catalyses is important from the viewpoint of green chemistry. The purpose of this study is to find suitable solid acid catalysts for the following three reactions in which homogeneous catalysts are used in practical processes:(1) Synthesis of bisphenol F from formaldehyde and phenol, (2) Synthesis of bis(4-hydroxy-3, 5-dimethylphenyl)methane from formaldehyde and 2, 6-dimethylphenol, (3) Synthesis of bis(4-aminophenyl)methane from formaldehyde and aniline. The catalysts examined were various types of zeolite and mesoporous aluminosilicate molecular sieves(Al-MCM-41). All the reactions were carried out in liquid phase at atmospheric pressure. Commercial phenol, 2, 6-dimethylphenol, aniline, and formalin were used as reactants without purification. It is clarified in this study that weak acid sites are responsible for three reactions because of a high reactivity of formaldehyde and the following catalysts and reaction conditions for each reaction are suitable. That is, for reaction (1) the suitable catalysts are high silica H-beta zeolite and Al-MCM-41 and a high phenol/formaldehyde ratio is required to attain a high selectivity, for reaction (2) the suitable catalyst is Al-MCM-41 and the selectivity is almost 100% at any reactant ratios, and for reaction (3) the active catalysts are Al-MCM-41 and H-beta and USY zeolites, the selectivity is affected by reaction spaces, and USY exhibits the highest selectivity.