金属卟啉仿生催化环烷烃选择氧化过程规律及机理研究

Contraposing the problems such as poor selectivity , low yield , undefined mechanism, serious environment pollution and high energy consumption existed in the various selective oxidation of cycloalkanes to cycloalkanols, cycloalkanones, dicarboxylic acid and other important fine chemical intermediates, and surrounding the key scientific issues such as the different ring strain of cycloalkanes, and the effect of the ring strain on C-H oxidation and/or C-C broken to open ring, the reaction mechanism and laws between different catalysts and substrates, the objectives of this project will aim to precisely quantitatively characterize the results between theory chemical calculations and experiments by using chemometrics methods, establish the overall research mode for simultaneous analysis of multi-factor and multivariate at various different level in the selective oxidation process of cycloalkanes, deeply excavate and interpret the truly relevant feature values and parameters (cycloalkane structure parameters, metalloporphyrin structure parameters, transfer process and reaction conditions, etc.),then effectively quantitatively characterize for characteristic relation between truly relevant feature values and parameters and catalytic activity or selectivity in selective oxidation process of cycloalkanes, hereby exactly construct the high-precision QSAR/QSSR models for quantitative describing the nature factors affecting the feedstock conversion and product selectivity in the oxidation of cycloalkanes.Based on the above research,the activity and selectiveity for the oxidation of cycloalkanes to different products with metalloporphyrins as the catalysts can be precisely adjusted by controlling a serious of influenced factors and condtions, and energy saving as well as emission reduction also will be achieved throughout the reaction process. Therefore, the theory of biomimetic catalysis will be further enriched and developed.

针对目前环烷烃选择氧化合成环烷醇、酮、二元酸等重要精细化学品或中间体的方法存在选择性差、收率低、机理不清、污染重、能耗高等诸多问题，围绕不同环烷烃环内张力及结构差异及其对环上C-H氧化和/或C-C断裂开环的影响，以及不同催化剂与不同底物间作用机理及规律等关键科学问题，采用化学计量学方法高精度定量表征理论化学计算与实验结果之间的特征相关性，建立环烷烃选择氧化反应的多因素、多层次、多水平、多变量整体研究模式，挖掘和阐释环烷烃选择氧化过程中多水平下多层次因素的各种变量和参数与其催化氧化活性或选择性真正相关的特征描述符和参数（环烷烃结构参数、金属卟啉结构参数、传递过程和反应条件参数等），构建高精度的QSAR/QSSR模型，定量描述和表征环烷烃氧化反应中影响原料转化率和产物选择性的系列本质因素，实现对金属卟啉催化选择氧化环烷烃反应活性及选择性的精确调控，实现整个过程节能减排，丰富和发展仿生催化理论。

针对目前环烷烃选择氧化合成环烷醇，酮，二元酸等重要精细化学品或中间体的方法存在选择性差，收率低，机理不清，污染重，能耗高等诸多问题，项目系统研究了O2作为氧化剂，环烷烃(C5~C8)的无选择性自氧化温度，明确了环戊烷，环己烷，环庚烷和环辛烷分别在120 ºC，130 ºC，120 ºC和105 ºC开始表现出明显的自氧化行为，确定了金属卟啉催化O2高选择性氧化环烷烃(C5~C8)的反应温度范围；系统研究了反应温度，O2压力，反应时间，金属卟啉结构和环烷烃结构对金属卟啉催化O2氧化环烷烃(C5~C8)C-H键及C-C键的影响及权重，确定了O2氧化环烷烃(C5~C8)的主要影响因素为反应温度，金属卟啉的中心金属和环烷烃自身结构；系统研究了金属卟啉对应的金属盐Co(AcO)2和氧化产物对O2氧化环烷烃(C5~C8) C- H键及C-C键的影响，确定了催化剂降解产物及氧化产物对反应体系的影响及程度；系统研究了金属卟啉催化O2氧化环烷烃(C5~C8)C-H键及C-C键产物的生成顺序及相互转化，借助量子化学计算确定了金属卟啉催化O2氧化环烷烃的一般性规律：首先金属卟啉活化O2分子拔取环烷烃的H原子，生成的环烷基捕获O2分子生成环烷基过氧基，环烷基过氧基进一步转化为环烷基醇和环烷基酮(环烷基醇为主)，环烷基醇深度氧化为环烷基酮，环烷基酮转化为脂肪族二酸，生成的脂肪族二酸可以脱羧生成碳原子减少的脂肪族二酸；根据所得金属卟啉催化O2氧化环烷烃(C5~C8)的一般性规律，分别以四(p-氯苯基)卟啉Zn (II)和四(p-氯苯基)卟啉Cu(II)促进四(p-氯苯基)卟啉Co(II)催化O2氧化环烷烃中间产物过氧化物的可控转化，环己烷转化率由3.43%分别提高到4.18%和4.41%，KA油选择性由90.7%分别提高到96.4%和97.2%，并且对其他环烷烃底物也表现出明显的促进作用。借助所得环烷烃催化氧化规律，实现了金属卟啉催化O2氧化环烷烃(C5~C8)C-H键及C-C键的调控。该研究对烃类C-H键的高选择性催化氧化及其氧化产物的精确合成具有一定的参考价值，对丰富和发展基于金属卟啉的仿生催化理论体系也具有重要的意义。