Preparation And Applications Of Resinic Catalysts Of Halogenated Sulfonic Polystyrenes And Aminosulfonic Polystyrenes

Macroporous sulfonic resins are extensively used as catalysts in various chemical reactions. In general, they are sulfonated from the macroporous poly(styrene-co-divinylbenzene) using concentrated sulfuric acid as the sulfonating agent, which means that the structure of them is mainly composed of two parts, namely the polystyrene carrier and acid active sites-SO3 H.Therefore, functional modification of sulfonic resinsshould be revolved mainly around the polystyrene carrier and active sites.In this study, the precursor sulfonic resin was halogenated, and a series of halogenated macroporous sulfonic resinswas synthesized.These modified resins possessed a larger contact angle of water droplet than the precursor and a significantly improved thermal stability. Furthermore,the base sites were introduced into benzene rings of the resin, and a series of aminosulfonicresins containing N-SO3 H, N-Alkyl-SO3 H, and-NH2-SO3 Htype structure were synthesized, respectively.The effect of amines and sulfonic acids distribution onthe catalytic activity of aminosulfonicresins had been analyzed experimentally, and the proton transfer in catalytic process was also studied.1. A series of halogenated macroporous sulfonic resins A-15-Cl, A-15-Br and A-15-I were synthesized from the precursor Amberlyst 15 by a typical halogenation reaction. Halogenation reaction not only has almost no effect on pore structure but also has contributed to a larger contact angle of water droplet than the precursor and a significantly improved thermal stability.2. The catalytic activity of the halogenated macroporous sulfonic resins was evaluated by the Biginelli reactionand follows the order: A-15-Br > A-15-Cl ≈ A-15-I > Amberlyst 15.Their catalytic activity was much improved because of the positive inductive effect and hydrophobicity of the halogenated groups,among which the resin A-15-Br-4 containing 31.27% bromine exhibited the best catalytic activity and excellent recyclability.3. The preparation ofmethylgallate, ethylgallate and propyl gallate using the halogenated macroporous sulfonic resins as efficient catalysts with methanol, ethanol, n-propanol and gallic acid as materials was studied. Based on this, octyl gallate and dodecyl gallate were synthesized from these gallate low carbon esters by transesterification reaction. In addition, the resin A-15-Br-4 containing 31.27% bromine also exhibited the best catalytic activity and excellent recyclability.4. A series of novelmacroporous aminosulfonic resins PS-NHSO3 H, PS-CH2NHSO3 H, PS-NH-(CH2)3-SO3 H, PS-CH2NH-(CH2)3-SO3 H, PS-NH2-SO3 H and PS-CH2NH2-SO3 H were synthesized, andthey were evaluated for the catalytic activity of macroporous aminosulfonic resins via the Knoevenagel and deacetalizationKnoevenagel reaction in detail.The distribution of amines and sulfonic acids has an effect on catalytic activity,among which the resin PS-CH2NH2-SO3 H exhibited the best cooperative catalysis and excellent recyclability.5. The synthesis ofxanthene derivatives using the macroporous aminosulfonic resins of-NH2 and-NHSO3 H functionalization as efficient catalysts was studied. The results showed that the resin PS-NH2 exhibited excellent catalytic activity and recyclabilitywhen it catalyzed synthesis of 2,2’-arylmethylene bis(3-hydroxy-2-cyclohexene-1-one) and tetrahydroxanthene derivatives, and aseries ofoctahydroxanthene derivativescatalyzed by the resinPS-NHSO3 H were alsoefficiently synthesized. In addition, aconjugated delocalization system was formed between amino and benzene in the resin PS-NH2 or PS-NHSO3 H, which led to the basicity of amino decreasing evidently, and the amino groupplayed a role of proton transfer.