The cycloaddition reaction of CO_(2)with epoxide not only effectively reduces the concentration of CO_(2)in the atmosphere,but also has excellent industrial application value and up to 100%atom utilization,but there are difficulties in separation and recovery of traditional homogeneous catalysts,harsh reaction conditions of traditional heterogeneous catalysts,and activation of CO_(2)molecules.In this paper,an easily synthesized heterogeneous catalyst CeNCl/C was used to catalyze the cycloaddition reaction of CO_(2)with styrene oxide,with a high yield of 92.7%,a high selectivity of 96.7%,a turnover numbers(TON)value of 349,and a good stability demonstrated in six cycle tests(equivalent to 216 h of testing).Through comprehensive studies,it was shown that CeNCl/C contains Lewis acid-base centers as active centers,which can effectively reduce the energy barrier required for ring opening of the reaction substrate,enhance the adsorption and activation of CO_(2),and promote the formation of intermediates,which led to the acquisition of excellent catalytic activity.
Li LiuLingling ZhangXiang ChuBaokang GengHuilin WangZongxiang LiXiao WangShuyan SongHongjie Zhang
Allenes are a class of unsaturated compounds containing a propadiene structural moiety,exhibiting essential physiological,pharmacological,and various reactivities.Their(4þ3)cycloaddition reaction has become an effective method for synthesizing seven-membered rings,especially for heterocycles.This method has been continuously improved and developed.Herein,we review the(4þ3)cycloaddition of allenes,focusing on the developed methodologies and the outlook in this field from 2013 to 2023.
Comprehensive Summary,Valbenazine(Ingrezza),a potent and highly selective inhibitor of vesicular monoamine transporter type 2(VMAT2)through the active metabolite hydrotetrabenazine(HTBZ),has been approved for the treatment of tardive dyskinesia and,very recently,for chorea,which is associated with Huntington's disease.Despite numerous synthetic efforts dedicated to the synthesis of HTBZ,the industrial preparation of valbenazine uses dihydroisoquinoline as a starting material and the chiral resolution of racemic HTBZ derived from ketone reduction.Herein,we present a practical synthesis of HTBZ and valbenazine featuring a highly stereoselective 1,3-dipolar cycloaddition and enzymatic kinetic resolution.The cascade process includes cycloaddition,N—O bond cleavage,and lactamization,which proved to be operationally simple.The allure of the enzymatic resolution developed in this work offers a rapid access toward affording tetrahydroisoquinoline(THIQ)-fused piperidine in the production of medically significant compounds,such as yohimbine and reserpine.
Yalan PengZuming LinLili ZhuShiqing HanSha-Hua HuangRan Hong
Carbon dioxide (CO_(2)) is a principal greenhouse gas with a substantial impact on global climate change. The photocatalytic reduction of CO_(2) represents an economically viable and environmentally benign approach. This technique involves the catalysis of the reaction between CO_(2) and epoxides under photocatalytic conditions to yield cyclic carbonates. Notably, this process has garnered significant attention due to its high atomic efficiency and alignment with green chemistry principles. Increasingly, photocatalysts are employed to facilitate the synthesis of cyclic carbonates, demonstrating outstanding performance even under natural light. This review evaluates the current state of research on the photocatalytic cycloaddition of CO_(2) with epoxides, analyzes the reaction mechanism and key influencing factors, and provides a comparative summary of the photocatalysts developed in this domain. Additionally, this paper underscores the significance of the reaction devices. The paper explores reaction devices with potential applications for photocatalytic CO_(2) and epoxides and envisions future integrations of CO_(2) photocatalytic cycloaddition reactions with advanced reaction devices for practical applications in this area.
The catalytic asymmetric(3+3)cycloaddition between different 2-indolylmethanols has been established,in which a series of chiral indole-fused six-membered heterocycles were constructed in high yields with excellent enantioselectivities.This work not only has established the first catalytic asymmetric cycloaddition between different 2-indolylmethanols but also provided a powerful strategy for constructing enantioenriched indole-fused six-membered rings.Additionally,biological evaluation discovered some products with promising antitumor activities.Notably,theoretical calculations performed on the reaction pathway and activation mode provide an in-depth understanding of this catalytic asymmetric(3+3)cycloaddition among different 2-indolylmethanols,which will advance the understanding of the chemistry of indolylmethanols.
Tianzhen LiSijia LiuShufang WuQi ChengQun ChenYinchun JiaoYuchen ZhangFeng Shi
Developing an energy supply-chain based on renewable biomass holds great potential to build a low carbon society.High-energy-density(HED)jet fuel,featuring unique fused/strained cycloalkanes,is of great significance for volume-limited military aircrafts,as their high density and combustion heat can extend flight duration and increase the payload.Therefore,the exploration of biomass-based routes towards HED fuel has drawn much attention over the past decade.Cycloaddition reaction features rapid construction of various carbocycles in an atom-and step-economical fashion.This elegant strategy has been widely applied in the manufacture of sustainable HED fuel.Here we carefully summarize the progress achieved in this fascinating area and the review is categorized by the cycloaddition patterns including[4+2],[2+2],[4+4],and[2+1]cycloadditions.Besides,the energy densities of the as-prepared biofuels and petroleumbased fuels(conventional Jet-A and advanced JP-10)are also compared.This review will provide important insights into rational design of new HED fuel with different ring-types/sizes and inspire the chemists to turn those literature studies into practical applications in military field.
With regard to green chemistry and sustainable development,the fixation of CO_(2) into epoxides to form cyclic carbonates is an attractive and promising pathway for CO_(2) utilization.Metal oxides,renowned as promising eco-friendly catalysts for industrial production,are often undervalued in terms of their impact on the CO_(2)addition reaction.In this work,we successfully developed ZnO nanoplates with(002)surfaces and ZnO nanorods with(100)surfaces via morphology-oriented regulation to explore the effect of crystal faces on CO_(2) cycloaddition.The quantitative data obtained from electron paramagnetic resonance spectroscopy indicated that the concentration of oxygen vacancies on the ZnO nanoplate surfaces was more than twice that on the ZnO nanorod surfaces.Density functional theory calculations suggested that the(002)surfaces have lower adsorption energies for CO_(2) and epichlorohydrin than the(100)surfaces.As a result,the yield of cyclochloropropene carbonate on the ZnO nanoplates(64.7%)was much greater than that on the ZnO nanorods(42.3%).Further evaluation of the reused catalysts revealed that the decrease in the oxygen vacancy concentration was the primary factor contributing to the decrease in catalytic performance.Based on these findings,a possible catalytic mechanism for CO_(2) cycloaddition with epichlorohydrin was proposed.This work provides a new idea for the controllable preparation of high-performance ZnO catalysts for the synthesis of cyclic carbonates from CO_(2) and epoxides.
Yongjian WeiYing LiYunfei XuYinghui SunTong XuHaiou LiangJie Bai
A new family of dibenzoullazine derivatives was synthesized through 1,3-dipolar cycloaddition of polycyclic aromatic azomethine ylides with alkynylbenziodoxoles followed by oxidation.The benziodoxole moiety in the resulting products was used as a versatile linchpin for the synthesis of structurally diverse functional dibenzoullazines that are difficult to access by other synthetic methods.
Hui HanGlen Wee Zhuan GohYongxin LiNaohiko YoshikaiShingo Ito
With the advantages of low raw material cost and 100%atom utilization,the synthesis of high value-added chemical product cyclic carbonates by the cycloaddition of CO_(2)to epoxides has become one of the most prospective approaches to achieve the industrial utilization of CO_(2).In the reported catalytic systems,the complexity of the catalyst synthesis process,high cost,separation difficulties,and low CO_(2)capture limit the catalytic efficiency and its large-scale application.In this paper,Ag nanoparticles loaded on polyethyleneimine(PEI)-modified UiO-66-NH_(2)(Ag/PEI@UiO-66-NH_(2))are successfully synthesized by in situ immersion reduction.The Ag nanoparticles and the amino groups on the surfaces of PEI@UiO-66-NH_(2)contribute to the adsorption of CO_(2)and polarization of C–O bonds in epoxides,thereby boosting the conversion capability for the CO_(2)cycloaddition reaction.At the amount of propylene oxide of 0.25 mol and the catalyst dosage of 1%of the substrate,the yield and selectivity of propylene carbonate are up to 99%.In addition,the stability and recyclability of Ag/PEI@UiO-66-NH_(2)catalyst are attained.The Ag/PEI@UiO-66-NH_(2)catalyst also demonstrates a wide range of activity and distinctive selectivity toward cyclo-carbonates in the cycloaddition of CO_(2)to epoxides.This work provides a guide to designing a highly efficient catalyst for in situ capture and high-value utilization of CO_(2)in industrial applications.
