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大学英语Asymmetric C(sp)-C(sp2) bond formation to give enantiomerically enriched 1,3-butadienyl-2-carbinols occurred through a homoallenylboration reaction between a 2,3-dienylboronic ester and aldehydes under the catalysis of a chiral phosphoric acid (CPA). A diverse range of enantiomerically enriched butadiene-substituted secondary alcohols with aryl,heterocyclic, and aliphatic substituents were synthesized in very high yield with high enantioselectivity. Preliminary density functional theory (DFT) calculations suggest that the reaction proceeds via a cyclic six-membered chairlike transition state with essential hydrogen-bond activation in the allene reagent.The catalytic reaction was amenable to the gram-scale synthesis of a chiral alkyl butadienyl adduct, which was converted into an interesting optically pure compound bearing a benzo-fused spirocyclic cyclopentenone framework.在手性磷酸(CPA)催化剂条件下,2,3-硼酸酯和醛通过反应生成了富对映体的1,3-丁二烯-2-甲醇,这里面含有不对称的碳(sp杂化)碳(sp2杂化)键。不同丁二烯取代的二级醇的富对映体和芳香烃、杂环以及脂肪烃的合成可以有高产率和很好的对映体选择性。初步的密度泛函理论(DFT)的计算表明,这个反应是在丙二醇试剂中通过对氢键必要的活化而经过了一个六元环椅型结构的过渡态实现的。这个反应对于手性的烷基二烯的克级别反应而言是容易控制的,而手性的烷基二烯可以转化为一种有趣的耐苯并环戊酮的光学纯化合物。Yiyong Huang,Xing Yang, Zongchao Lv,Chen Cai,Cheng Kai, Yong Pei,and Yu Feng. Asymmetric Synthesis of 1,3-Butadienyl-2-carbinols by the Homoallenylboration of Aldehydes with a Chiral Phosphoric Acid CatalystJ.Angewandte Chemie,2015,127:7407-7410C-H bonds are ubiquitous in organic compounds. It would, therefore, appear that direct functionalization of substrates by activation of C-H bonds would eliminate the multiple steps and limitations associated with the preparation of functionalized starting materials. Regioselectivity is an important issue because organic molecules can contain a wide variety of C-H bonds. The use of a directing group can largely overcome the issue of regiocontrol by allowing the catalyst to come into proximity with the targeted C-H bonds. A wide variety of functional groups have been evaluated for use as directing groups in the transformation of C-H bonds. In 2005, Daugulis reported the arylation of unactivated C(sp(3)-H bonds by using 8-aminoquinoline and picolinamide as bidentate directing groups, with Pd(OAc)2 as the catalyst. Encouraged by these promising results, a number of transformations of C-H bonds have since been developed by using systems based on bidentate directing groups. In this Review, recent advances in this area are discussed.C-H键有机化合物中无处不在。这样看来,通过使用已活化C-H键的直接功能性底物可以消除与合成功能性原料有关的反应的多步数以及限制条件。区域选择性是一个重要的问题,因为有机分子含有多种多样的C-H键。而一种定向取代基可以使催化剂进入到目标C-H键的附近,这种定向取代基的使用可以很大程度上克服区域选择性的问题。在C-H键的转化中,作为定向基团的各种官能团已经被评估。在2005年,Daugulis报道通过利用8-氨基喹啉和吡啶酰胺作为双齿配位定向官能团,Pd(OAc)2作为催化剂,使未活化的C(sp3杂化)-H键发生芳基化反应。受这些好的实验结果的鼓舞,通过使用基于双齿定向基团的系统,许多C-H键的转换已经被开发出来。在这篇评论中,对这方面的最新进展进行了讨论。G Rouquet,N Chatani.Catalytic functionalization of C(sp2)-H and C(sp3)-H bonds by using bidentate directing groupsJ. Angewandte Chemie ,2013,52(45):11726-11743.The development of new microporous materials for adsorption separation processes is a rapidly growing field because of potential applications such as carbon capture and sequestration (CCS) and purification of clean-burning natural gas. In particular, new metal-organic frameworks (MOFs) and other porous coordination polymers are being generated at a rapid and growing pace. Herein, we address the question of how this large number of materials can be quickly evaluated for their practical application in carbon dioxide separation processes. Five adsorbent evaluation criteria from the chemical engineering literature are described and used to assess over 40 MOFs for their potential in CO(2) separation processes for natural gas purification, landfill gas separation, and capture of CO(2) from power-plant flue gas. Comparisons with other materials such as zeolites are made, and the relationships between MOF properties and CO(2) separation potential are investigated from the large data set. In addition, strategies for tailoring and designing MOFs to enhance CO(2) adsorption are briefly reviewed.吸附分离过程中新型微孔材料的发展是一个快速发展的领域,因为它在碳捕获与封存(CCS)和清洁燃烧天然气的进化方面有着潜在的应用。尤其是在新型金属有机框架(MOFs)和其它多孔配位聚合物领域以快速增长的趋势发展。于是,我们致力于解决在二氧化碳分离过程中,如何迅速评价这么多材料的实际应用。对于天然气净化、垃圾填埋气分离和电厂烟气中二氧化碳的捕捉这种情形而言,化学工程文献中的五种吸附评价标准被用于评估在二氧化碳分离过程中可能超过40 MOFs的情况。与其他材料进行对比,如分子筛、MOF特性与二氧化碳分离势的关系,都通过大数据而被分析。此外,也对通过设计MOF的策略来提高二氧化碳的吸附进行了简要的回顾。B Youn-Sang,Q Snurr.Development and evaluation of porous materials for carbon dioxide separation and captureJ.Angewandte Chemie,2011, 50(12):11586-11596.Using bottom-up chemistry techniques, the composition, size, and shape in particular can now be controlled uniformly for each and every nanocrystal (NC). Research into shape-controlled NCs have shown that the catalytic properties of a material are sensitive not only to the size but also to the shape of the NCs as a consequence of well-defined facets. These findings are of great importance for modern heterogeneous catalysis research. First, a rational synthesis of catalysts might be achieved, since desired activity and selectivity would be acquired by simply tuning the shape, that is, the exposed crystal facets,of a NC catalyst. Second, shape-controlled NCs are relatively simple systems, in contrast to traditional complex solids, suggesting that they may serve as novel model catalysts to bridge the gap between model surfaces and real catalysts.采用自下而上的化学技术,可以使每一个纳米晶体(NC)在组成、大小、尤其是形状上得到统一的控制。通过对纳米晶体形状控制的研究表明,一种材料的催化性能是敏感的,这不经体现在纳米晶体的大小上,而且体现在它的形状上,这是十分明确的事实。这些发现对于现代多相催化研究具有重要意义。首先,这是一种合成催化剂的合理的合成方法,因为合成所需要的活性和选择性可以通过简单的调整形状来实现,也就是说,调整纳米晶体催化剂被暴露的晶面即可。第二,与传统的复合固体相比,形状被控制的纳米晶体是相对简单的晶体,这表明它们可能作为新型的催化剂模型可以缩小模型表面与真实催化剂之间的差距K Zhou,Y Li.Catalysis based on nanocrystals with well-defined facetsJ.Angewandte Chemie,2012,51(3):602-613.Metal-organic frameworks (MOFs) are an important class of hybrid inorganic-organic materials. In this tutorial review, a progress report on the postsynthetic modification (PSM) of MOFs is provided. PSM refers to the chemical modification of the MOF lattice in a heterogeneous fashion. This powerful synthetic approach has grown in popularity and resulted in a number of advances in the functionalization and application of MOFs. The use of PSM to develop MOFs with improved gas sorption, catalytic activity, bioactivity, and more robust physical properties is discussed. The results reported to date clearly show that PSM is an important approach for the development and advancement of these hybrid solids.金属有机骨架(MOFs)是一类重要的有机-无机杂化材料。在本篇评论中,提供了一篇关于金属有机框架的后改进(PSM)的进度报告。PSM指的是在一种非均匀的条件下发生的金属有机框架晶格的化学改性。这种强有力的合成方法已经变得越来越流行并且引发了在金属有机框架合成及应用方面的许多突破。在发展金属有机框架下的对于PSM的应用,同时在改进气体吸附、催化剂活性、生物活性以及更多强大物性方面的应用也在被探讨。许多研究报告结果清除的表明,PSM对于混合固体的发展和突破而言是一种重要的方法。KK Tanabe,SM Cohen.Postsynthetic modification of metal-organic frameworks-a progress reportJ.Chemical Society Reviews,2011,40(2):498-519Transition metal-catalysed higher-order carbocyclisation reactions represent an important class of reactions due to their ability to construct complex polycyclic systems in a highly selective and atom-economical fashion. A key and striking feature with these

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