Development of Practical Catalysts by an Efficient Integration of A Dynamic Bifunctional Catalyst and Supercritical Fluid Chemistry

高效的催化反应过程是将新型双功能催化剂和独特的反应介质——超临界流体相结合而发展起来的。不对称C-C键形成手性双功能分子催化剂的研究进展：研究了一种概念上新的促进对映选择性C-C键形成的过渡金属类手性双功能分子催化剂。与手性酰胺配合物的不对称Nicahel反应顺利进行，得到相应的高原子经济性和高ee的手性加合物。目前的双功能分子催化剂为立体选择性转化（包括对映选择性碳氢键和碳碳键）以及碳氮键和碳零键的形成开辟了新的基础。由2-甲基氮吡啶和超临界二氧化碳制备的脂肪族聚脲胺共聚物的双刺激响应行为：在超临界条件下，氮吡啶和二氧化碳发生反应，得到含有氨基和氨基的无规共聚物。2-甲基吡啶与二氧化碳的共聚产物对温度和ph值的响应均表现出剧烈而快速的相变，反应性能可由超临界状态下的反应条件控制。超临界甲醇在多功能化固体催化剂上的连续化学选择性甲基化：利用连续流固定床反应器，成功地研究了在金属氧化物催化剂上，超临界甲醇对苯酚和乙醇胺的化学选择性甲基化。苯酚在双功能催化剂Cs-P-Si上的甲基化反应选择性地产生0-甲基化产物，而在弱酸碱双功能催化剂ZrO_2上的甲基化反应主要产生c -甲基化产物。同时，氨基醇在Cs-P-Si混合氧化物上的甲基化产生优先的n甲基化产物。超临界条件下固体催化剂的酸碱性质和超临界流体的性质对反应的化学选择结果有很大影响。少

Highly efficient catalytic reaction processes have been developed by a combination of the conceptually new bifunctional catalysts and unique reaction media, supercritical fluids.1. Development of Chiral Bifunctional Molecular Catalysts for Asymmetric C-C Bond Formation : A conceptually new chiral bifunctional transition metal-based molecular catalyst promoted the enantioselective C-C bond formation has been developed. Asymmetric Nicahel reactions with chiral amide complexes proceeds smoothly to give the corresponding chiral adducts with high atom economy and high ee. The present bifunctional molecular catalyst offers a great opportunity to open up new fundamentals for stereoselective transformation including enantioselective C-H and C-C as well as C-N and C-0 bond formation.2. Double Stimuli-Responsive Behavior of Aliphatic Poly(urethane-amine) Copolymers Prepared from 2-Methylaziridine and Supercritical Carbon Dioxide : A reaction of aziridines and carbon dioxide proceeds under superc … More ritical conditions to give random copolymers containing urethane and amine moieties. The resulting copolymeric products obtained from 2-methylaziridine and carbon dioxide exhibit sharp and rapid phase transitions in response to both temperature and pH. The responsive property can be controlled by the reaction conditions under supercritical state.3. Continuous Chemoselective Methylation of Functionalized compounds with Supercritical Methanol over Mulitifunctionalized Solid Catalysts : The chemoselective methylation of phenols and ethanol amine with supercritical methanol over the metal oxide catalysts has been successfully developed using a continuous flow fixed bed reactor. Methylation of phenols over the bifunctional catalyst, Cs-P-Si, having both very weak acidic and basic sites, gives selectively the 0-methylation products, while the weaker acid-base bifunctional catalyst ZrO_2 provids mainly C-methylation products. Whilst, the methylation of aminoalcohols over the Cs-P-Si mixed oxide produces preferentially N-methylated products. The chemoselective outcome of the reaction is highly influenced by the acid-base character on the solid catalysts under supercritical conditions and the nature of the supercritical fluids. Less