绿色催化二氧化碳、炔丙醇和亲核试剂的三组分反应（英文）

近些年来,将CO_2转化为高附加值化学品受到广泛关注。其中,CO_2、炔丙醇和亲核试剂的三组分反应可用于制备用途广泛的羰基化合物,该方法具有步骤经济性、原子经济性等优点。由于CO_2分子具有热力学稳定性和动力学惰性,多数CO_2参与的化学反应在热力学上不支持。然而,CO_2、炔丙醇和双亲核试剂三组分反应是热力学有利的CO_2转化反应,实现了邻二醇或氨基醇和CO_2到环状碳酸酯以及2-噁唑啉酮的高效转化。本综述旨在于总结并讨论近年来CO_2、炔丙醇和亲核试剂三组分反应制备多种羰基化学物的主要进展。     

铜(Ⅰ)催化的常压二氧化碳、炔丙醇和仲胺三组分反应

氨基甲酸酯类化合物是一类重要的有机化合物,在医药、农药以及有机合成中有着广泛应用,也可以作为氨基的保护基团.炔丙醇、仲胺和CO_2在铜(Ⅰ)催化下能够发生三组分"一锅"反应,高收率、高选择性地生成β-羰基氨基甲酸酯.该反应能够在常压CO_2的条件下进行,具有反应条件温和、原子经济性高和底物适应范围宽等优点.通过控制氧气含量,可以高选择性地形成β-羰基氨基甲酸酯.多种炔丙醇和仲胺均能高效反应,生成相应的β-羰基氨基甲酸酯.该方法避免了利用高压CO_2提高反应效率的问题,是二氧化碳低压温和条件下制备β-羰基氨基甲酸酯类化合物的简便途径.     

芳炔参与的三组分芳基化反应进展

三组分反应具有操作简单、反应效率高等优势,契合“原子经济、绿色环保”等原则.目前,芳炔参与的无过渡金属催化的芳基化反应主要分为以下三种类型:(1)直接芳基化反应;(2)基于σ-键或π-键的芳炔插入反应;(3)芳炔参与的三组分反应.相比于发展较为成熟的直接芳基化反应和基于σ-键或π-键的芳炔插入反应,芳炔参与的三组分反应机理尚不清楚,相关的综述也较为少见.为了科研工作者方便查阅、了解芳炔参与的三组分反应,对近年来芳炔参与的芳基化三组分反应研究进展进行综述.     

高氯酸银催化炔丙醇与酸酐反应制备烯二酮

烯二酮类化合物是一类重要的工业原料和多功能的有机合成中间体,在制药工程、香料加工和化学合成中有着广泛的应用。利用高氯酸银（AgClO4）催化炔丙醇与酸酐的反应,首次合成了几种此前从未报道过的新型烯二酮类化合物。该反应过程无需溶剂,且具有操作简单、条件温和、绿色环保、底物普适性广等优点,这表明了该方法在烯二酮合成领域巨大的应用潜力。     

手性炔丙醇的不对称催化合成研究进展

手性炔丙醇是一种重要中间体化合物,作为合成多种光学活性化合物的重要合成前体受到学者们广泛关注。目前通过酮的不对称催化反应合成手性炔丙醇的研究开发具有极大发展前景,因此本文围绕酮类化合物的不对称催化反应来进行综述,结合相关反应最新研究进展,全面总结并分类了不对称催化还原、催化不对称加成等反应类型,介绍了合成不同结构手性炔丙醇的新思路,并对酮的不对称催化反应在未来能成为工业化重要生产途径作出展望。     

铜催化的多组分反应合成二芳基炔丙胺类衍生物

以醛、苯乙炔和二芳胺为原料, 三组分一锅法合成了一系列二芳基炔丙胺类化合物. 产物的结构通过1H NMR, 13C NMR和HRMS证实.     

有机相中利用脂肪酶催化的醇解反应拆分炔丙醇酮乙酸酯

 研究了有机相中脂肪酶催化的炔丙醇酮乙酸酯的立体选择性醇解反应, 考察了碱的种类、酰基受体和溶剂等对反应的影响. 结果表明, 以四氢呋喃为溶剂, CH3OH 为酰基受体, Lipase PLG 脂肪酶为催化剂, Na2CO3 为碱性添加剂, 高底物浓度下 40 oC 反应 96 h 后, 底物转化率和产物 ee 值分别达到 49.5% 和 99.5%. 碱的添加极大地提高了反应速度.     

铜催化β-酮酸炔丙醇酯的不对称脱羧炔丙基烷基化反应

正Angew.Chem.Int.Ed.2014,53,1410~1414通过过渡金属催化的炔丙基取代反应,可以非常便利地在反应产物上引入富电子的碳碳叁键官能团,进而可以实现多种复杂化合物的合成.因此这一反应近来受到越来越多的关注并取得了很大的进展.多种过渡金属如Ru、Cu、Ni等及氮、氧、碳等亲核试剂已被成功应用于该反应中.但利用简单的酮及其烯醇衍生物作为亲核试剂的炔丙基取代化反应目前仍鲜有成功的报导.中国科学院大连化学物理研究所胡向平研究员和徐杰研究员等利用手性铜催     

炔丙醇与烯醇硅醚的直接亲核取代反应

报道了一种在对甲苯磺酸催化下炔丙醇和烯醇硅醚的直接亲核取代反应,并有效合成γ-炔基酮类化合物的新方法.该反应在敞口环境下使用未经干燥处理的溶剂即可获得良好的产率.     

Palladium‐Catalyzed Coupling of Propargylic Alcohols with Boronic Acids under Ambient Conditions

A highly efficient palladium‐catalyzed direct coupling of propargylic alcohols with organoboronic acids to synthesize tri‐ and tetra‐substituted allenes has been developed under mild reaction conditions. Many useful functional groups are tolerated in this process with high to excellent yields. Preliminary biological studies showed that several tri‐ and tetra‐substituted allenes exhibited potent anti‐diabetic activities.     

Rh‐Catalyzed Reaction of Propargylic Alcohols with Aryl Boronic Acids–Switch from β‐OH Elimination to Protodemetalation

It is known that Rh‐catalyzed reaction of propargylic alcohols with aryl metallic reagents undergoes S_N2’‐type reaction affording allenes via a sequential arylmetalation and β‐OH elimination process. Here we report a Rh/Ag‐cocatalyzed reaction of propargylic alcohols with organoboronic acids affording stereo‐defined (E)‐3‐arylallylic alcohols via arylmetalation and protodemetalation with a high regio‐ and stereoselectivity under very mild conditions. The reaction exhibits a good substrate scope and the compatibility with synthetically useful functional groups with no racemization for optically active propargylic alcohols. Such a reaction may also be extended to homopropargylic alcohols with a remarkable regioselectivity and exclusive E‐stereoselectivity.     

二氧化碳电还原反应的理论研究

Converting CO₂ into value-added products via sustainable energy, such as electrical energy, has several advantages. First, it is one of the most promising routes to close the carbon loop and plays a crucial role in significantly reducing the CO₂ concentration in the atmosphere. Second, it can utilize CO₂ as a valuable industry reactant that can store energy by converting electrical energy to chemical energy. Although the CO₂ reduction reaction has been studied for more than three decades, the sluggish kinetics remain a bottleneck, which requires a highly efficient catalyst. However, none of the reported catalysts meets the requirements for any practical application due to low activity and poor selectivity. To rationally design a more efficient CO₂ reduction catalyst, understanding the reaction mechanism is crucial. Although it is challenging to experimentally capture and characterize the reactive intermediates, atomic modeling serves as an alternative for providing an understanding of the elementary reactions on a microscale. Significant progress has been made in understanding the reaction mechanism using multiscale simulations. In this study, important progress in revealing the reaction mechanism of CO₂ reduction using computational simulation in recent years is summarized. First, the advances in simulation methods for electrochemical reactions are introduced, and the advantages and disadvantages of various methods are compared. Second, the detailed reaction mechanism of CO₂ reduction to various major products, such as CO, CH₄, and C₂H₄, and minor products, such as ethanol and acetate, are disused. Different results obtained from different approximations are compared, while a mechanism that can better explain the existing experimental results is recommended. Third, the operando technique, such as ambient pressure X-ray photoelectron spectroscopy, is disused. The operando analysis results are direct evidence to validate the theoretically proposed reaction pathway. In turn, the theoretical predictions can help resolve the experimental spectrum, which is usually too complex to refer to a reference system. The combination of theory and operando experiments should be one of the most promising directions in determining the reaction mechanism. Fourth, novel synthesis strategies are discussed. These new ideas are beneficial for simplifying the synthesis process or increasing the diversity of products. Finally, the recent progress in the application of machine learning to big data for CO₂ reduction is discussed. These new powerful tools may play a crucial role in reaction mechanism studies. Overall, in the study of electrochemical reaction mechanism, theoretical simulation can provide the reaction details and energy information of elementary reactions at the atomic level. Therefore, in the study of electrochemical reaction mechanism of carbon dioxide, the microscopic mechanism that the experiment cannot provide is supplemented. On the one hand, it explains the existing experimental phenomena; however, on the other hand, it provides new insights for the study of reaction mechanism. On this basis, the use of new research paradigms, such as high-throughput computing and machine learning, provides new ideas for a rational design for accelerating material development.     

光电催化二氧化碳还原研究进展

CO_2是最常见的化合物,作为潜在的碳一资源,可用于制备多种高附加值的化学品,如一氧化碳、甲烷、甲醇、甲酸等。传统的热催化转化CO_2方法能耗高,反应条件苛刻。因此,如何在温和条件下高效地将CO_2转化成高附加值的化学品,一直以来是催化领域的研究热点和难点之一。光催化技术反应条件温和、绿色环保。然而,纯光催化反应普遍存在太阳能利用效率有限,光生载流子分离效率低等问题。针对上述问题,在光催化的基础上引入电催化,可以提高载流子的分离效率,在较低的过电位下,实现多电子、质子向CO_2转移,从而提高催化反应效率。总之,光电催化技术可以结合光催化和电催化的优势,提高CO_2催化还原反应效率,为清洁、绿色利用CO_2提供了一种新方法。本文依据光电催化CO_2还原反应基本过程,从光吸收、载流子分离和界面反应等三个角度综述了光电催化反应的基本强化策略,并对未来可能的研究方向进行了展望。     

Catalysis of Carbon Dioxide Photoreduction on Nanosheets: Fundamentals and Challenges

The transformation of CO₂ into fuels and chemicals by photocatalysis is a promising strategy to provide a long‐term solution to mitigating global warming and energy‐supply problems. Achievements in photocatalysis during the last decade have sparked increased interest in using sunlight to reduce CO₂. Traditional semiconductors used in photocatalysis (e.g. TiO₂) are not suitable for use in natural sunlight and their performance is not sufficient even under UV irradiation. Some two‐dimensional (2D) materials have recently been designed for the catalytic reduction of CO₂. These materials still require significant modification, which is a challenge when designing a photocatalytic process. An overarching aim of this Review is to summarize the literature on the photocatalytic conversion of CO₂ by various 2D materials in the liquid phase, with special attention given to the development of novel 2D photocatalyst materials to provide a basis for improved materials.     

Development of a syn‐Selective Mannich Reaction of Aldehydes with Propargylic Imines by Dual Catalysis: Asymmetric Synthesis of Functionalized Propargylic Amines

Direct coupling of enolizable aldehydes with C‐alkynyl imines is realized affording the corresponding propargylic Mannich adducts of syn configuration, thus complementing previous methods that gave access to the anti‐isomers. The combination of proline and a urea Brønsted base cocatalyst is key for the reactions to proceed under very mild conditions (3–10 mol % catalyst loading, dichloromethane as solvent, ?20 °C, 1.2 molar equivalents of aldehyde) and with virtually total stereocontrol (syn/anti ratio up to 99:1; ee up to 99 %). Some possibilities of further chemical elaboration of adducts are also briefly illustrated.     

CS2与大气颗粒物的多相催化反应研究

利用原位FTIR,XRD,XPS,BET,质谱和连续微量反应等手段研究了大气颗粒物及部分氧化物样品上CS₂多相催化反应,确认了反应产物,并对催化剂的晶化状况和比表面积等进行了考察.结果表明,CS₂在氧化物和大气颗粒物样品上发生氧化反应,生成COS及单质硫,部分样品上生成CO₂,活化状态下的[S]在大气颗粒物表面上能被进一步氧化为六价态硫.收集所得到的大气颗粒物样品成分主要是Ca(Al₂Si₂O₈)·4H₂O;CS₂在氧化物或大气颗粒物样品上催化生成COS是催化剂表面吸附氧的作用之故.     

酶法催化二氧化碳制备高附加值化学品研究进展

现代工业的发展不断消耗煤、石油、天然气等碳化石燃料,并产生了大量的温室气体CO₂,使人类面临能源和环境的双重挑战,开发绿色能源、控制CO₂对环境的影响迫在眉睫.CO₂是一种廉价的碳源,可通过化学法、光化学法、电化学法或酶法等转化为高附加值含碳化学品,实现CO₂的资源化循环利用,是解决全球碳排放所带来的能源和环境危机的双赢策略.受CO₂胞内天然生物转化的启发,酶法为CO₂的循环利用带来了新的机遇,相比于传统的化学及光、电化学法,可表现出绿色、高效、温和、高选择性等优点,有望为CO₂高值化利用带来新的契机.有鉴于此,本文从胞内CO₂生物转化机理出发,综述了国内外近年来多种单酶及多酶级联催化CO₂高值化利用的最新研究进展,并交叉论述了固定化酶催化体系的构建、酶定向进化和改造、酶催化过程调控等内容,总结了酶法转化目前存在的缺陷和不足,并提出了展望,以期为酶法催化CO₂高值化利用提供一定的参考和借鉴.     

超临界CO_2络合萃取绿茶中Cu、Pb和Cd的研究

本文采用超临界CO2络合萃取法萃取绿茶中的Cu、Pb和Cd。分别考察了不同改性剂和络合剂、萃取压力、萃取温度以及静态和动态萃取时间对三种重金属的萃取率影响。研究结果表明:以磷酸三丁酯(TBP)/HNO3为络合剂,乙醇为改性剂,在20MPa、333K、静态和动态萃取时间分别为30min的最佳条件下,Cu、Pb和Cd的萃取率分别为78.3%、73.2%和69.5%。