【摘要】：隨著全球"溫室效應(yīng)"和能源危機(jī)的加劇,近幾年二氧化碳作為一種豐富、無毒、廉價(jià)的碳一原料廣受關(guān)注.目前,在溫和條件下實(shí)現(xiàn)二氧化碳的化學(xué)轉(zhuǎn)化仍然是一個(gè)十分具有挑戰(zhàn)性的課題,其關(guān)鍵的科學(xué)問題是二氧化碳分子的有效活化.本文發(fā)現(xiàn),在不添加任何助催化劑的條件下,季膦鹽型雙功能金屬Salen配合物不僅能夠以有機(jī)胺、含氫硅烷和二氧化碳為原料,在溫和條件下通過甲�；磻�(yīng)實(shí)現(xiàn)系列甲酰胺類衍生物的高效合成,而且能夠催化二氧化碳和環(huán)氧化合物的環(huán)加成反應(yīng),從而實(shí)現(xiàn)環(huán)狀碳酸酯的宏量制備.催化實(shí)驗(yàn)及動(dòng)力學(xué)研究結(jié)果表明,該雙功能催化劑通過金屬活性中心和鹵素陰離子之間的分子內(nèi)協(xié)同催化作用,既可利用高活性鋅氫鍵調(diào)控含氫硅烷中的硅氫鍵,又能通過高活性鋁氧鍵激活環(huán)氧化物的三元環(huán),進(jìn)而導(dǎo)致二氧化碳的方便插入及高效活化.譬如:當(dāng)使用1.0 mol%鋅催化劑時(shí),僅加入1倍當(dāng)量的苯硅烷,在25℃和0.5 MPa的條件下,反應(yīng)6 h后N-甲酰苯胺收率高達(dá)99%;而當(dāng)使用0.5 mol%鋁催化劑時(shí),在100℃和2.0 MPa的條件下反應(yīng)2 h,環(huán)加成反應(yīng)轉(zhuǎn)化率接近100%,環(huán)狀碳酸酯選擇性可達(dá)99%.另外,上述兩個(gè)反應(yīng)都表現(xiàn)出優(yōu)異的底物擴(kuò)展性,具有良好的官能團(tuán)相容性.在此基礎(chǔ)上通過構(gòu)建反應(yīng)動(dòng)力學(xué)模型,采用在線紅外跟蹤技術(shù),闡明了協(xié)同活化機(jī)制在二氧化碳催化轉(zhuǎn)化過程中的作用原理及共性/個(gè)性規(guī)律,豐富并發(fā)展了二氧化碳活化的基本理論.最后,單組分催化劑可通過溶劑調(diào)變的方式很容易實(shí)現(xiàn)回收及再利用,表現(xiàn)出"均相催化,兩相分離"的特點(diǎn).循環(huán)使用五次后催化活性和選擇性未見明顯下降.
[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，

本文編號：2290692