季膦盐型双功能金属Salen配合物催化二氧化碳转化为高附加值化学品（英文）
发布时间：2018-10-24 07:14
【摘要】：随着全球"温室效应"和能源危机的加剧,近几年二氧化碳作为一种丰富、无毒、廉价的碳一原料广受关注.目前,在温和条件下实现二氧化碳的化学转化仍然是一个十分具有挑战性的课题,其关键的科学问题是二氧化碳分子的有效活化.本文发现,在不添加任何助催化剂的条件下,季膦盐型双功能金属Salen配合物不仅能够以有机胺、含氢硅烷和二氧化碳为原料,在温和条件下通过甲酰化反应实现系列甲酰胺类衍生物的高效合成,而且能够催化二氧化碳和环氧化合物的环加成反应,从而实现环状碳酸酯的宏量制备.催化实验及动力学研究结果表明,该双功能催化剂通过金属活性中心和卤素阴离子之间的分子内协同催化作用,既可利用高活性锌氢键调控含氢硅烷中的硅氢键,又能通过高活性铝氧键激活环氧化物的三元环,进而导致二氧化碳的方便插入及高效活化.譬如:当使用1.0 mol%锌催化剂时,仅加入1倍当量的苯硅烷,在25℃和0.5 MPa的条件下,反应6 h后N-甲酰苯胺收率高达99%;而当使用0.5 mol%铝催化剂时,在100℃和2.0 MPa的条件下反应2 h,环加成反应转化率接近100%,环状碳酸酯选择性可达99%.另外,上述两个反应都表现出优异的底物扩展性,具有良好的官能团相容性.在此基础上通过构建反应动力学模型,采用在线红外跟踪技术,阐明了协同活化机制在二氧化碳催化转化过程中的作用原理及共性/个性规律,丰富并发展了二氧化碳活化的基本理论.最后,单组分催化剂可通过溶剂调变的方式很容易实现回收及再利用,表现出"均相催化,两相分离"的特点.循环使用五次后催化活性和选择性未见明显下降.
[Abstract]:As the global "Greenhouse Effect" and energy crisis intensifies, carbon dioxide as a rich, non-toxic, cheap carbon-material has received widespread attention in recent years. At present, the chemical conversion of carbon dioxide under mild conditions is still a very challenging subject, the key scientific problem is the effective activation of carbon dioxide molecules. In this paper, it is found that, without adding any cocatalyst, the Salen complex with quaternary phosphine salt can not only use organic amine, hydrosilane and carbon dioxide as raw materials. A series of formamide derivatives were synthesized by formylation under mild conditions, and the cycloaddition reaction of carbon dioxide and epoxide could be catalyzed, thus the macrosynthesis of cyclic carbonate could be realized. The results of catalytic experiment and kinetic study show that the bifunctional catalyst can regulate the hydrosilyl bond in hydrosilane by using highly active zinc hydrogen bond through intramolecular synergistic catalysis between metal active center and halogen anion. The ternary ring of epoxide can be activated by high active aluminum oxygen bond, which leads to the convenient insertion and efficient activation of carbon dioxide. For example, when 1. 0 mol% zinc catalyst was used, only 1 times equivalent phenylsilane was added, the yield of N- formylaniline was up to 99% after 6 h reaction at 25 鈩，
本文编号：2290692
[Abstract]:As the global "Greenhouse Effect" and energy crisis intensifies, carbon dioxide as a rich, non-toxic, cheap carbon-material has received widespread attention in recent years. At present, the chemical conversion of carbon dioxide under mild conditions is still a very challenging subject, the key scientific problem is the effective activation of carbon dioxide molecules. In this paper, it is found that, without adding any cocatalyst, the Salen complex with quaternary phosphine salt can not only use organic amine, hydrosilane and carbon dioxide as raw materials. A series of formamide derivatives were synthesized by formylation under mild conditions, and the cycloaddition reaction of carbon dioxide and epoxide could be catalyzed, thus the macrosynthesis of cyclic carbonate could be realized. The results of catalytic experiment and kinetic study show that the bifunctional catalyst can regulate the hydrosilyl bond in hydrosilane by using highly active zinc hydrogen bond through intramolecular synergistic catalysis between metal active center and halogen anion. The ternary ring of epoxide can be activated by high active aluminum oxygen bond, which leads to the convenient insertion and efficient activation of carbon dioxide. For example, when 1. 0 mol% zinc catalyst was used, only 1 times equivalent phenylsilane was added, the yield of N- formylaniline was up to 99% after 6 h reaction at 25 鈩，
本文编号：2290692
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