功能化有序介孔有机硅的设计、合成、形貌调控和用作烯丙位氧化催化剂的研究

Enones are the meterials and intermediates of organic chemistry industry, building blocks of natural products, and prochiral compounds.The direct transformation from available alkenes to enones is considered a most convenient route. However, the existing methods remaines limits, such as the preparation of complex ligand, use of noble metal, separation difficulty between catalysts and products as well as recovery of catalysts. On the basis of published works, our team found that the Cu catalysts, made from the mesoporous materials immobilizated pyridine and carboxyl group functionalized ionic liquids onto sillica, displayed better the activity and selsctivity for enones and the recovery of catalyst in the allylic oxidation of α/β-iononedienes, compared with existing homogeneous method in organic solvents and ionic liquids. The results showed that the further research on this direction may be valuable. Therefore, in this project, ionic ligand functionalized periodic mesoporous organosilica materials containing N, O bidentate ligands or O, N, O tridentate ligands, made from pyridine carboxylic compounds will be designed, synthesized, and used to prepare the heterogeneous catalyst for allylic oxidation by chelating Rh, Pd, Cu, and Fe compunds. The affect of composition and structure of organosilica precursor, different templates, and hydrolysis and condensation conditions on surface properties and catalytic performances will be studied. The study aims at providing a new idea and experimental data to develop the heterogeneous catalytic system for the allylic oxidation into enones.

烯酮是精细化工的原料和中间体、天然产物的基本单元和手性前体。从烯烃直接选择性烯丙位氧化获得烯酮是最简便的路线。但目前烯丙位氧化方法多是均相系统，存在使用复杂配体和贵金属催化剂，催化剂不能回收再利用以及易对产物和环境造成污染等问题。离子液体功能化有序介孔有机硅，为非均相催化剂的研发提供了新材料和解决方案。课题组探索发现，吡啶-羧基离子配体功能化的介孔有机硅材料制备的铜催化剂，在紫罗兰二烯的烯丙位氧化中，显示出较现有单相体系更好的活性和选择性，催化剂易于分离和回收再利用；有进一步研究的价值。因此，本项目拟设计合成吡啶羧基系列N、O二齿或O、N、O三齿离子配体功能化有序介孔有机硅材料；制备负载铑、钯、铜、铁的烯并位氧化非均相催化剂；研究离子配体有机硅氧烷前体的组成和结构，模板剂种类和水解缩合条件，对材料形貌、表面性质及催化性能的影响，旨在为开发烯丙位氧化合成烯酮的非均相催化剂提供新思路和实验数据

本项目希望开发功能化离子液体结合有序介孔有机硅载体材料，负载金属催化剂，用于合成烯酮的烯丙位氧化，筛选催化性能好的非均相催化剂。本项目进行了以下几方面的研究工作。.1..以甲基咪唑、咪唑、-氯丙基-三乙氧基硅、2-吡啶甲酸、2，6-二甲酸吡啶、2-氨基-4-吡啶甲酸和2-氨基-6-吡啶甲酸为原料，合成了甲基咪唑阳离子/咪唑阳离子吡啶羧酸阴离子功能化的有序介孔有机硅单体。.2..单体与TEOS，在模板剂下，共聚制备了材料(OMS-单-IL-Pca)和挂载铜催化剂(Cu@OMS-单-IL-Pca)，材料（PMO-双-IL-Pca/or APca）和挂载铜催化剂(Cu@PMO-双-IL-Pca/or aPca)，材料均为有序介孔结构，表面积186.5 ~921.08 m2/g，配体修饰量分别是0.579~1.111mmol/g和0.31~0.66 mmol/g，铜的载量0.634~1.1532mmol/g和0.12~0.675mmol/g，分解温度240和270℃。.3..催化β-紫罗兰酮烯丙位氧化反应，总共28个催化剂，除5个催化结果与均相CuCl2.2H2O催化剂相当外，23个优于均相系统，β-紫罗兰酮的转化率73.44~99 %，4-氧代-β-紫罗兰酮收率52.25~70.2%。Cu@PMO-2,4apc-IL-30表现突出，重复使用7次，β-ionone的转化率均>95%，4-氧代-β-紫罗兰酮选择性能保持>60%。.4.. Cu/Fe/Co/Pd @PMO-双-IL-Pca-15催化活性顺序，Co催化剂> Cu催化剂>Fe催化剂，Co催化剂底物转化率98.17%，目标物产率74.78%。.5..Cu@PMO-2,4apc-IL-30对a-蒎烯等9个环烯烯丙位氧化，7个底物获得了90·100%转化率，60.16~79.2%产率。.6..发现了新的非均相催化剂，可用于药物、香料和农业化学品的烯丙位氧化。