Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene(TCPD) that is a potential high-density fuel precursor. GC and MS analysis shows that the...Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene(TCPD) that is a potential high-density fuel precursor. GC and MS analysis shows that the adducts contain two isomers, namely exo- and endo-TCPD. Theoretical simulation shows that although the transition state of endo-TCPD has a lower activation energy, exo-TCPD is thermodynamically preferred. Polar solvents can accelerate the reaction rate and improve the exo/endo ratio of TCPD because the transition state of exo-TCPD has a higher polarity than that of endo-TCPD. The solvent effect follows the order of polarity: benzyl methanol〉cyclohexanone〉toluene. The conversion rises when the temperature ranges from 120 to 150 ℃, but the selectivity of TCPD slightly decreases. Increasing the pressure can improve the conversion but the exo/endo ratio of TCPD is unchanged. The apparent kinetics in different solvents was determined via nonlinear regression. The activation energies are 99.47, 101.15, and 107.32 kJ/mol for benzyl methanol, cyclohexanone, and toluene, respectively. The optimal reaction conditions are as follows: benzyl methanol as solvent, temperature 150 ℃, and pressure 900 kPa. After an 11-hour reaction, a conversion of 58.0%, a TCPD selectivity of 95.7%, and an exo/endo ratio of 1/5.3 has been obtained.展开更多
Double asymmetric Diels-Alder reaction of 1(SR)-p-Tolylsulfinyl-3-penten-2-one with cyclopentadiene using a chiral titanium reagent was performed. The diastereoselectivity dependent on the size of aryl substituent i...Double asymmetric Diels-Alder reaction of 1(SR)-p-Tolylsulfinyl-3-penten-2-one with cyclopentadiene using a chiral titanium reagent was performed. The diastereoselectivity dependent on the size of aryl substituent involved in the chiral ligands was discussed Absolute configuration of the cycloadducts was conformed. Dramatic reversal of selectivity is observed.展开更多
The cycloaddition reactions between ketene or substituted ketenes and cyelopentadiene have been studied theoretically by means of the semiempirical AMI method.Three different substituted ketenes have been selected and...The cycloaddition reactions between ketene or substituted ketenes and cyelopentadiene have been studied theoretically by means of the semiempirical AMI method.Three different substituted ketenes have been selected and ten transition states,corresponding to different approach geometries have been located and characterized,The regioselectivity and stereoselectivity of the reactions are correctly predicted by the calculations and the reaction mechanisms are analyzed in terms of electronic and steric effects of the substitutents on the reacting ketene and cyc-lopentadiene.展开更多
The development of a facile and efficient polymerization to prepare cyclopentadiene-containing polymers is of vital importance and highly desired. In this work, a metal-free multicomponent polymerization of activated ...The development of a facile and efficient polymerization to prepare cyclopentadiene-containing polymers is of vital importance and highly desired. In this work, a metal-free multicomponent polymerization of activated diyne, electrophilic styrene and isocyanide for the preparation of highly substituted poly(cyclopentadiene) was established. Soluble and thermally stable polymers with high molecular weights are obtained in high yields under mild conditions. By introducing the tetraphenylethene or triphenylamine moiety into polymer backbones, the resultant polymers show unique aggregation-induced emission(AIE)characteristics. Interestingly, AIE polymers can also be generated in situ from non-AIE monomers. Moreover, the prepared polymers can generate photopatterns to function as photoresists and can also serve as visualizing agents to selectively stain the lipid droplets in live cells. This efficient polymerization will open up enormous opportunities for preparing functional cyclopentadiene-containing polymers applicable in diverse areas.展开更多
Several γ-Al2O3 supported Pd-Ni bimetallic nanocatalysts (Pd-Ni (x:y)[Al2O3; where x and y represent the mass ratio of Pd and Ni, respectively) were prepared by the impregnation method and used for selective hyd...Several γ-Al2O3 supported Pd-Ni bimetallic nanocatalysts (Pd-Ni (x:y)[Al2O3; where x and y represent the mass ratio of Pd and Ni, respectively) were prepared by the impregnation method and used for selective hydrogenation of cyclopentadiene to cyclopentene. The Pd-NiJAl2O3 samples were confirmed to generate Pd-Ni bimetallic nanoparticles by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The catalytic activity was assessed in view of the effects of different mass ratios of Pd and Ni, temperature, pressure, etc. Among all the samples, the Pd-Ni (1:1 )/Al2O3 (PN-1:1 ) catalyst showed extremely high catalytic ability. The conversion of cyclopentadiene and selectivity for cyclopentene can be simultaneously more than 90%.展开更多
H-1,2,3-Diazaphospholes 3a3h were prepared from various ketone acylhydrazones and phosphorus trichlo-ride in the presence of triethylamine. Compounds 3 underwent feasible hetero-Diels-Alder reactions with cyclopen-tad...H-1,2,3-Diazaphospholes 3a3h were prepared from various ketone acylhydrazones and phosphorus trichlo-ride in the presence of triethylamine. Compounds 3 underwent feasible hetero-Diels-Alder reactions with cyclopen-tadiene to afford the respective anellated [1,2,3]diazaphospholes 4a4d as well as 4a'4d' in moderate yields. The endo rule in the reaction was observed under kinetic control conditions.展开更多
The ethylene/cyclopentadiene (CPD) copolymerization behavior by using fluoro-substituted bis(fl- enaminoketonato) titanium complexes [FC6H4NC(CH3)CHCO(CF3)]2TiC12 (la-lc) has been investigated in detail. Upo...The ethylene/cyclopentadiene (CPD) copolymerization behavior by using fluoro-substituted bis(fl- enaminoketonato) titanium complexes [FC6H4NC(CH3)CHCO(CF3)]2TiC12 (la-lc) has been investigated in detail. Upon utilizing MMAO as a cocatalyst, complexes la-lc exhibit high catalytic activities, affording the copolymers with high molecular weight and unimodal molecular weight distribution. Compared with non-substituted complex [C6HsNC(CH3)CHCO(CF3)]2TiC12 (1), complexes la-lc can produce the copolymers with CPD incorporation adjusted in a wide range due to the enhancement of electrophilicity of metal center caused by introducing electron-withdrawing groups. Especially complex lc bearing fluorine at the para-position of N-aryl moiety provides the highest CPD incorporation, which is nearly two times (18.5 mol%) higher than the non-substituted complex 1 (8.9 mol%) under the same conditions. The highest CPD incorporation up to 24.6 mol% can be easily achieved using this complex. 1H-and 13C-NMR spectra demonstrate that these fluoro-substituted complexes possess regioselective nature with exclusive 1,2-insertion fashion, and alternating ethylene-CPD sequence can be detected at high CPD incorporation.展开更多
Promoted by samarium diiodide in THF, the α,β-unsaturated alkynones were reduced to afford intermolecular reductive coupling products. The multiply substituted cyclopentadienes were prepared conveniently in good yie...Promoted by samarium diiodide in THF, the α,β-unsaturated alkynones were reduced to afford intermolecular reductive coupling products. The multiply substituted cyclopentadienes were prepared conveniently in good yields.展开更多
A three-component condensation was applied for the preparation of cyclopentadiene derivatives through the reaction of primary amines,alkyl propiolate and dialkyl acetylenedicarboxylate in the presence of catalytic amo...A three-component condensation was applied for the preparation of cyclopentadiene derivatives through the reaction of primary amines,alkyl propiolate and dialkyl acetylenedicarboxylate in the presence of catalytic amount of ZnO-nanorods(Zn-NR) under solvent-free conditions at 50 ℃.The method has proved to be synthetically green,simple,and effective with high atom economy and yield.The catalyst also revealed significant reusability.Moreover,the antioxidant activity and free radical scavenging capacity of the newly synthesized derivatives 4a,4b,4c,and 4d was screened using free radical scavenging 2,2-diphenyl-1-picrylhydrazyl(DPPH) and ferric reducing antioxidant power(FRAP)assays and compared with hydroxytoluene(BHT) and tert-butylhydroquinone(TBHQ).These compounds do not exhibit good DPPH radical scavenging,but they have a desirable FRAP.展开更多
An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was developed.The Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical car...An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was developed.The Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical carbon dioxide in the absence of any polymerization inhibitor to produce the corresponding5-vinyl-2-norbornene in satisfactory yield with high selectivity.展开更多
Recent advances in technologies of reactive distillation(RD) offer various design concepts for chemical processes.For separation of cracking C5 fraction, one of the main challenges is improving the conversion of cyclo...Recent advances in technologies of reactive distillation(RD) offer various design concepts for chemical processes.For separation of cracking C5 fraction, one of the main challenges is improving the conversion of cyclopentadiene(CPD) and the recovery of isoprene(IP). In the current work, a novel reactive distillation column with several liquid-holdup regions was designed, since it allows long residence time and provides flexibility for narrowing the efficiency gap between reaction and distillation. By use of Aspen Plus, a corresponding mathematic model was established and verified to be accurate. Following that, comprehensive studies were carried out for the design of liquid-holdup regions position. Details and principles about the separation performance with the liquid-holdup regions were revealed and optimized parameters were determined with 100 theoretical plates,feed position of 35 th plate, and four liquid-holdup regions at 25 th, 60 th, 75 th and 90 th plate. The designed RD column could well meet the technical requirement, and influence of other important factors including residence time, operating pressure and reflux ratio was further investigated.展开更多
High-energy–density(HED)fuel is specifically pivotal to improve the performance of volume-limited aircrafts.The widely used HED fuels composed of polycyclic hydrocarbons are mainly synthesized from petroleum feedstoc...High-energy–density(HED)fuel is specifically pivotal to improve the performance of volume-limited aircrafts.The widely used HED fuels composed of polycyclic hydrocarbons are mainly synthesized from petroleum feedstocks.In order to ensure abundant supply,alternative resources such as coal should be considered.Herein,we summarize the synthesis methods and properties of typical HED fuels by using petroleum-derived cyclopentadiene(CPD)as key feedstock through dimerization,cycloaddition,hydrogenation and isomerization/photoisomerization reactions,and then propose a blueprint for synthesizing HED fuels from coal.The method to produce CPD from coal is analyzed and feasibility is demonstrated according to theoretical calculations and reported results.This review provides a novel route for synthesis of HED fuels from coal.展开更多
A well-dispersed metallic palladium catalyst modified by polymer-anchored thioether ligands was used for the hydrogenation of cyclopentadiene to cyclopentene with high activity and selectivity in ambient condition. Th...A well-dispersed metallic palladium catalyst modified by polymer-anchored thioether ligands was used for the hydrogenation of cyclopentadiene to cyclopentene with high activity and selectivity in ambient condition. The evidences to show the modification of catalytic properties by polymer anchored ligands were given.展开更多
Symmetric, diesters of cis- or trans- bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylate were prepared by aqueous Diels-Alder reaction of cyclopentadiene with symmetric diester of fumarate or maleate.
Herein we report the reactivity of N-(2,4-dicyano-1,5-dimethyl-3-arylcyclopenta-2,4-dienyl)-2,2,2- trifluoroacetamides and N,N-dimethyl-4-nitrosoaniline which provide compounds derived from Ehrlich-Sachs condensation,...Herein we report the reactivity of N-(2,4-dicyano-1,5-dimethyl-3-arylcyclopenta-2,4-dienyl)-2,2,2- trifluoroacetamides and N,N-dimethyl-4-nitrosoaniline which provide compounds derived from Ehrlich-Sachs condensation, dihydrofuran derivatives and fulvene derivatives by adjusting the reaction conditions.展开更多
Sodium hydride is widely used as Lewis base in organic syntheses, but cannot reduce the carbon-carbon double bond alone. Recently, we have found that tricyclopentadienyl rare earth complexes-sodium hydride systems are...Sodium hydride is widely used as Lewis base in organic syntheses, but cannot reduce the carbon-carbon double bond alone. Recently, we have found that tricyclopentadienyl rare earth complexes-sodium hydride systems are not only nice reducing-展开更多
The direct addition of aryl C—H bond to carbon-heteroatom double bond by transition-metal-catalyzed C—H activation has been extensively investigated in the past decade. However, the enantioselective intermolecular C...The direct addition of aryl C—H bond to carbon-heteroatom double bond by transition-metal-catalyzed C—H activation has been extensively investigated in the past decade. However, the enantioselective intermolecular C—H addition to aldehyde has not yet been reported and is of significant challenge. Rh(III)-catalyzed highly enantioselective intermolecular C—H addition of aryl oxime ethers to glyoxylates is reported. Chiral mandelic acid esters were obtained in excellent yields (up to 98%) and enantioselectivity (up to 99% ee) in the presence of a chiral CpRh(III) catalyst under mild conditions. The substituents on the Cp ring and BINOL skeleton were responsible for the high enantioselectivity observed. The method displays a broad substrate scope and good functionality tolerance. These results provide not only a promising C—H addition approach but also a proof of concept for developing broader asymmetric C—H addition reactions.展开更多
基金Supported by Fundamental Research Project of Commission of ScienceTechnology and Industry for National Defense of China(NoA1420060192)
文摘Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene(TCPD) that is a potential high-density fuel precursor. GC and MS analysis shows that the adducts contain two isomers, namely exo- and endo-TCPD. Theoretical simulation shows that although the transition state of endo-TCPD has a lower activation energy, exo-TCPD is thermodynamically preferred. Polar solvents can accelerate the reaction rate and improve the exo/endo ratio of TCPD because the transition state of exo-TCPD has a higher polarity than that of endo-TCPD. The solvent effect follows the order of polarity: benzyl methanol〉cyclohexanone〉toluene. The conversion rises when the temperature ranges from 120 to 150 ℃, but the selectivity of TCPD slightly decreases. Increasing the pressure can improve the conversion but the exo/endo ratio of TCPD is unchanged. The apparent kinetics in different solvents was determined via nonlinear regression. The activation energies are 99.47, 101.15, and 107.32 kJ/mol for benzyl methanol, cyclohexanone, and toluene, respectively. The optimal reaction conditions are as follows: benzyl methanol as solvent, temperature 150 ℃, and pressure 900 kPa. After an 11-hour reaction, a conversion of 58.0%, a TCPD selectivity of 95.7%, and an exo/endo ratio of 1/5.3 has been obtained.
文摘Double asymmetric Diels-Alder reaction of 1(SR)-p-Tolylsulfinyl-3-penten-2-one with cyclopentadiene using a chiral titanium reagent was performed. The diastereoselectivity dependent on the size of aryl substituent involved in the chiral ligands was discussed Absolute configuration of the cycloadducts was conformed. Dramatic reversal of selectivity is observed.
文摘The cycloaddition reactions between ketene or substituted ketenes and cyelopentadiene have been studied theoretically by means of the semiempirical AMI method.Three different substituted ketenes have been selected and ten transition states,corresponding to different approach geometries have been located and characterized,The regioselectivity and stereoselectivity of the reactions are correctly predicted by the calculations and the reaction mechanisms are analyzed in terms of electronic and steric effects of the substitutents on the reacting ketene and cyc-lopentadiene.
基金supported by the National Natural Science Foundation of China(21788102,22101028)the Research Grants Council of Hong Kong(16304819,16305320,C6014-20W)+3 种基金the Innovation and Technology Commission(ITC-CNERC14SC01)the Natural Science Foundation of Guangdong Province(2019B121205002)Shenzhen Key laboratory of Functional Aggregate Materials(ZDSYS20212021222400001)the Nissan Chemical Industries,Ltd.
文摘The development of a facile and efficient polymerization to prepare cyclopentadiene-containing polymers is of vital importance and highly desired. In this work, a metal-free multicomponent polymerization of activated diyne, electrophilic styrene and isocyanide for the preparation of highly substituted poly(cyclopentadiene) was established. Soluble and thermally stable polymers with high molecular weights are obtained in high yields under mild conditions. By introducing the tetraphenylethene or triphenylamine moiety into polymer backbones, the resultant polymers show unique aggregation-induced emission(AIE)characteristics. Interestingly, AIE polymers can also be generated in situ from non-AIE monomers. Moreover, the prepared polymers can generate photopatterns to function as photoresists and can also serve as visualizing agents to selectively stain the lipid droplets in live cells. This efficient polymerization will open up enormous opportunities for preparing functional cyclopentadiene-containing polymers applicable in diverse areas.
基金the financial assistance from the National Natural Science Foundation of China (Nos.21272050,21371044,21472033)the Program for New Century Excellent Talents in University of the Chinese Ministry of Education (No.NCET-110627)
文摘Several γ-Al2O3 supported Pd-Ni bimetallic nanocatalysts (Pd-Ni (x:y)[Al2O3; where x and y represent the mass ratio of Pd and Ni, respectively) were prepared by the impregnation method and used for selective hydrogenation of cyclopentadiene to cyclopentene. The Pd-NiJAl2O3 samples were confirmed to generate Pd-Ni bimetallic nanoparticles by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The catalytic activity was assessed in view of the effects of different mass ratios of Pd and Ni, temperature, pressure, etc. Among all the samples, the Pd-Ni (1:1 )/Al2O3 (PN-1:1 ) catalyst showed extremely high catalytic ability. The conversion of cyclopentadiene and selectivity for cyclopentene can be simultaneously more than 90%.
基金the National Natural Science Foundation of China (No. 20372015).
文摘H-1,2,3-Diazaphospholes 3a3h were prepared from various ketone acylhydrazones and phosphorus trichlo-ride in the presence of triethylamine. Compounds 3 underwent feasible hetero-Diels-Alder reactions with cyclopen-tadiene to afford the respective anellated [1,2,3]diazaphospholes 4a4d as well as 4a'4d' in moderate yields. The endo rule in the reaction was observed under kinetic control conditions.
基金supported by the National Natural Science Foundation of China (No. 21234006)
文摘The ethylene/cyclopentadiene (CPD) copolymerization behavior by using fluoro-substituted bis(fl- enaminoketonato) titanium complexes [FC6H4NC(CH3)CHCO(CF3)]2TiC12 (la-lc) has been investigated in detail. Upon utilizing MMAO as a cocatalyst, complexes la-lc exhibit high catalytic activities, affording the copolymers with high molecular weight and unimodal molecular weight distribution. Compared with non-substituted complex [C6HsNC(CH3)CHCO(CF3)]2TiC12 (1), complexes la-lc can produce the copolymers with CPD incorporation adjusted in a wide range due to the enhancement of electrophilicity of metal center caused by introducing electron-withdrawing groups. Especially complex lc bearing fluorine at the para-position of N-aryl moiety provides the highest CPD incorporation, which is nearly two times (18.5 mol%) higher than the non-substituted complex 1 (8.9 mol%) under the same conditions. The highest CPD incorporation up to 24.6 mol% can be easily achieved using this complex. 1H-and 13C-NMR spectra demonstrate that these fluoro-substituted complexes possess regioselective nature with exclusive 1,2-insertion fashion, and alternating ethylene-CPD sequence can be detected at high CPD incorporation.
基金theNationalNaturalScienceFoundationofChina (No .2 0 0 72 0 33)andtheSpecializedResearchFundfortheDoctoralProgramofHigherEducation
文摘Promoted by samarium diiodide in THF, the α,β-unsaturated alkynones were reduced to afford intermolecular reductive coupling products. The multiply substituted cyclopentadienes were prepared conveniently in good yields.
基金the support of the Research Council of Iran University of Science and Technology, Tehran, Iran
文摘A three-component condensation was applied for the preparation of cyclopentadiene derivatives through the reaction of primary amines,alkyl propiolate and dialkyl acetylenedicarboxylate in the presence of catalytic amount of ZnO-nanorods(Zn-NR) under solvent-free conditions at 50 ℃.The method has proved to be synthetically green,simple,and effective with high atom economy and yield.The catalyst also revealed significant reusability.Moreover,the antioxidant activity and free radical scavenging capacity of the newly synthesized derivatives 4a,4b,4c,and 4d was screened using free radical scavenging 2,2-diphenyl-1-picrylhydrazyl(DPPH) and ferric reducing antioxidant power(FRAP)assays and compared with hydroxytoluene(BHT) and tert-butylhydroquinone(TBHQ).These compounds do not exhibit good DPPH radical scavenging,but they have a desirable FRAP.
基金the National Natural Science Foundation of China(Nos.21373041,21372035 and NSFC-IUPAC program,No.21361140375)for their financial support
文摘An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was developed.The Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical carbon dioxide in the absence of any polymerization inhibitor to produce the corresponding5-vinyl-2-norbornene in satisfactory yield with high selectivity.
文摘Recent advances in technologies of reactive distillation(RD) offer various design concepts for chemical processes.For separation of cracking C5 fraction, one of the main challenges is improving the conversion of cyclopentadiene(CPD) and the recovery of isoprene(IP). In the current work, a novel reactive distillation column with several liquid-holdup regions was designed, since it allows long residence time and provides flexibility for narrowing the efficiency gap between reaction and distillation. By use of Aspen Plus, a corresponding mathematic model was established and verified to be accurate. Following that, comprehensive studies were carried out for the design of liquid-holdup regions position. Details and principles about the separation performance with the liquid-holdup regions were revealed and optimized parameters were determined with 100 theoretical plates,feed position of 35 th plate, and four liquid-holdup regions at 25 th, 60 th, 75 th and 90 th plate. The designed RD column could well meet the technical requirement, and influence of other important factors including residence time, operating pressure and reflux ratio was further investigated.
基金supported by the National Natural Science Foundation of China(21978200)Scientific Research of the Ministry of Education of China(6141A02033522)。
文摘High-energy–density(HED)fuel is specifically pivotal to improve the performance of volume-limited aircrafts.The widely used HED fuels composed of polycyclic hydrocarbons are mainly synthesized from petroleum feedstocks.In order to ensure abundant supply,alternative resources such as coal should be considered.Herein,we summarize the synthesis methods and properties of typical HED fuels by using petroleum-derived cyclopentadiene(CPD)as key feedstock through dimerization,cycloaddition,hydrogenation and isomerization/photoisomerization reactions,and then propose a blueprint for synthesizing HED fuels from coal.The method to produce CPD from coal is analyzed and feasibility is demonstrated according to theoretical calculations and reported results.This review provides a novel route for synthesis of HED fuels from coal.
文摘A well-dispersed metallic palladium catalyst modified by polymer-anchored thioether ligands was used for the hydrogenation of cyclopentadiene to cyclopentene with high activity and selectivity in ambient condition. The evidences to show the modification of catalytic properties by polymer anchored ligands were given.
文摘Symmetric, diesters of cis- or trans- bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylate were prepared by aqueous Diels-Alder reaction of cyclopentadiene with symmetric diester of fumarate or maleate.
文摘Herein we report the reactivity of N-(2,4-dicyano-1,5-dimethyl-3-arylcyclopenta-2,4-dienyl)-2,2,2- trifluoroacetamides and N,N-dimethyl-4-nitrosoaniline which provide compounds derived from Ehrlich-Sachs condensation, dihydrofuran derivatives and fulvene derivatives by adjusting the reaction conditions.
文摘Sodium hydride is widely used as Lewis base in organic syntheses, but cannot reduce the carbon-carbon double bond alone. Recently, we have found that tricyclopentadienyl rare earth complexes-sodium hydride systems are not only nice reducing-
基金National Key R&D Program of China(2021YFA1500100)the National Natural Science Foundation of China(21821002,91856201,22071260)Science and Technology Commission of Shanghai Municipality(21520780100)for generous financial support.
文摘The direct addition of aryl C—H bond to carbon-heteroatom double bond by transition-metal-catalyzed C—H activation has been extensively investigated in the past decade. However, the enantioselective intermolecular C—H addition to aldehyde has not yet been reported and is of significant challenge. Rh(III)-catalyzed highly enantioselective intermolecular C—H addition of aryl oxime ethers to glyoxylates is reported. Chiral mandelic acid esters were obtained in excellent yields (up to 98%) and enantioselectivity (up to 99% ee) in the presence of a chiral CpRh(III) catalyst under mild conditions. The substituents on the Cp ring and BINOL skeleton were responsible for the high enantioselectivity observed. The method displays a broad substrate scope and good functionality tolerance. These results provide not only a promising C—H addition approach but also a proof of concept for developing broader asymmetric C—H addition reactions.