This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids(CPAs), a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral m...This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids(CPAs), a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral molecules. In the past years, different kinds of chiral phosphoric acids have been designed and developed into a privileged class of catalysts in asymmetric synthesis. A number of remarkable achievements have been made by many groups around the world. Due to length limitation, this review only summarizes those works published from January 2016 to November 2017. Meanwhile, catalytic systems which combine metal catalysts and chiral phosphoric acids will not be discussed in this review.展开更多
The asymmetric reaction of the chiron 2(5H)-furanones (4a-4c) with the Homer-Emmons reagents (5a-5b) has been investigated. The newly chiral organophosphorus derivatives 6 and 7 were obtained using the phosphoryl-stab...The asymmetric reaction of the chiron 2(5H)-furanones (4a-4c) with the Homer-Emmons reagents (5a-5b) has been investigated. The newly chiral organophosphorus derivatives 6 and 7 were obtained using the phosphoryl-stabilized carbanion as a building block in DMSO under mild conditions. Through the asymmetric introduction, the Horner-Emmons reagent could be transformed to a chiral building block to afford the novel functionalized phosphorus derivatives. The structures of the synthesized compounds 6 and 7 were identified on the basis of their elementary and spectroscopic data, such as IR, 1H NMR, 13C NMR, MS and X-ray crystallography. These results provided a valuable approach to the synthesis of potentially interesting chiral organophosphorus derivatives and probing their biological activities.展开更多
For the first time, synthetic dipeptides were applied to the catalysis of asymmetric Reformatsky reaction. Review in this domain & factors influencing enantioselectivity were discussed.
MBHA resin-supported tripeptide catalyst system containing L-proline unit has been developed for use in the direct asymmetric aldol reaction of acetone and aldehydes, which afford the corresponding products with satis...MBHA resin-supported tripeptide catalyst system containing L-proline unit has been developed for use in the direct asymmetric aldol reaction of acetone and aldehydes, which afford the corresponding products with satisfactory isolated yields and enantiomeric excesses. 2009 Hong Bin Zou. Published by E]sevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Chiral activated alkene, L-menthyl acrylate and (+)-N-α-phenylethyl acrylamide, induced asymmetric Baylis-HiUman reaction of aromatic aldehydes was realized at 25℃ for 7 days in Me3N/H2O/solvent homogeneous mediu...Chiral activated alkene, L-menthyl acrylate and (+)-N-α-phenylethyl acrylamide, induced asymmetric Baylis-HiUman reaction of aromatic aldehydes was realized at 25℃ for 7 days in Me3N/H2O/solvent homogeneous medium. The corresponding Baylis-Hillman adducts were obtained in good chemical yield with moderate to excellent diastereoselectivity (up to 99% de).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
5-(1-Menthyloxy)-2(5-H)-furanone is used as s chiral dipolarophile for thermal asymmetric 1,3-dipolar cycloaddition reaction with C-phenyl-N-phenyl nitrone to give the diastereomerically pure cycloaddition product.
Objective To explore the optimal primer ratio and concentration of asymmetric polymerase chain reaction (A-PCR) in producing hepatitis B virus (HBV) single-stranded DNA (ssDNA) for pyrosequencing. Methods A-PCR was ca...Objective To explore the optimal primer ratio and concentration of asymmetric polymerase chain reaction (A-PCR) in producing hepatitis B virus (HBV) single-stranded DNA (ssDNA) for pyrosequencing. Methods A-PCR was carried out to generate HBV ssDNA with forward to reverse primers of different ratios (50∶1, 100∶1) and concentrations (13.0 pmol/25μL and 0.14 pmol/25μL, 19.5 pmol/25μL and 0.21 pmol/25μL), and the product yield and quality were compared respectively. Results The forward to reverse primer ratio of 50∶1 provided better yield and concentration of 19.5 pmol/25μL and 0.21 pmol//25μL generated a clearer band. Conclusion A simple and feasible method to produce HBV ssDNA for pyrosequencing in batch is established.展开更多
Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantiose...Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantioselective annulation of SCBs with terminal alkynes remains a challenge.Herein,we report a rhodium-catalyzed asymmetric annulation reaction of SCBs with terminal alkynes,which relies on the newly identified chiral sulfinamide phosphine ligand Ming-Phos.This catalytic system exhibits unique effects under mild conditions,leading to the direct synthesis of structurally diverse chiral silacycles in moderate to good yields with high enantioselectivities(up to 95%ee).展开更多
An N-heterocyclic carbene(NHC)-catalyzed enantioselective Mannich reaction of the remoteγ-carbon of cyclopropylcarbaldehydes is disclosed for the first time.Diastereo-and enantiomerically enriched multicyclicδ-lacta...An N-heterocyclic carbene(NHC)-catalyzed enantioselective Mannich reaction of the remoteγ-carbon of cyclopropylcarbaldehydes is disclosed for the first time.Diastereo-and enantiomerically enriched multicyclicδ-lactam compound is afforded as the main product from 8 possible stereo-specific isomers through dynamic kinetic asymmetric transformation(DYKAT)processes.Multiple chiral functional molecules can be afforded from the lactam products through simple protocols with retentions of the optical purities.展开更多
Chirality,as the symmetric breaking of molecules,plays an essential role in physical,chemical and especially biological processes,which highlights the accurate distinction among heterochiralities as well as the precis...Chirality,as the symmetric breaking of molecules,plays an essential role in physical,chemical and especially biological processes,which highlights the accurate distinction among heterochiralities as well as the precise preparation for homochirality.To this end,the well-designed structure-specific recognizer and catalysis reactor are necessitated,respectively.However,each kind of target molecules requires a custom-made chiral partner and the dynamic disorder of spatial-orientation distribution of molecules at the ensemble level leads to an inefficient protocol.In this perspective article,we developed a universal strategy capable of realizing the chirality detection and control by the external symmetry breaking based on the alignment of the molecular frame to external stimuli.Specifically,in combination with the discussion about the relationship among the chirality(molecule),spin(electron)and polarization(photon),i.e.,the three natural symmetry breaking,single-molecule junctions were proposed to achieve a single-molecule/event-resolved detection and synthesis.The fixation of the molecular orientation and the CMOS-compatibility provide an efficient interface to achieve the external input of symmetry breaking.This perspective is believed to offer more efficient applications in accurate chirality detection and precise asymmetric synthesis via the close collaboration of chemists,physicists,materials scientists,and engineers.展开更多
Cinchonine was employed as backbone for the synthesis of novel phosphite compounds with diol substituents. These monophosphinites were provided in one pot with the yields ranged from 63% to 75%. Their structures were ...Cinchonine was employed as backbone for the synthesis of novel phosphite compounds with diol substituents. These monophosphinites were provided in one pot with the yields ranged from 63% to 75%. Their structures were confirmed by NMR spectroscopy and HRMS. C 2009 Sheng Yong Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Cinchonine alkaloid catalyzed enantioselective methanolysis of six 4-substituted 2-phenyl-5(4H)-oxazolones to (S)-methyl N-benzoyl-alpha-amino acid esters with 10-33% e.e and 72-81% yield.
An efficient asymmetric domino reaction of amino aldehyde to β,γ-unsaturated a-keto esters was achieved by using trans-perhydroindolic acid ld as a chiral organocatalyst with excellent asymmetric behavior. Under the...An efficient asymmetric domino reaction of amino aldehyde to β,γ-unsaturated a-keto esters was achieved by using trans-perhydroindolic acid ld as a chiral organocatalyst with excellent asymmetric behavior. Under the opti- mal reaction conditions, products with more than 99% de and up to 93% ee were obtained in high chemical yield (up to 98%) for a series of β,γ-unsaturated a-keto esters. The methodology provided an efficient route to dihydro- pyran derivatives containing many substituent groups (including amino groups).展开更多
Tetrahydrobenzo[5]helicenediol(THB-[5]HDIOL) derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas(LLB) aldol reactions of bulky aldehyde substrates was described. It was found ...Tetrahydrobenzo[5]helicenediol(THB-[5]HDIOL) derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas(LLB) aldol reactions of bulky aldehyde substrates was described. It was found that with dibromo-substituted helical diols P-4 a/M-4 a as additives, the prolinecatalyzed LLB aldol reaction of 9-anthraldehyde and acetone gave the product in 83% yield and 99% ee.Transition state models revealed an edge-to-face p-p stacking between the anthracenyl group in TS(R)and the phenyl group of the additive, which might result in the high enantioselectivity.展开更多
The 4,5-methano-L-proline was used as chiral organocatalysts in direct asymmetric aldol reactions.Under the optimal conditions,excellent enantioselectivities(up to 99%ee)were obtained with high chemical yields(up to 9...The 4,5-methano-L-proline was used as chiral organocatalysts in direct asymmetric aldol reactions.Under the optimal conditions,excellent enantioselectivities(up to 99%ee)were obtained with high chemical yields(up to 95%)for a series of aldehydes using only 5 mol%catalyst loading.To show the practicality of the method,the reaction was tested at a large scale.The reaction was complete in 16 h,and the aldol product was obtained in 86%yield and 93%ee.展开更多
This highlight summarizes a recent development of a catalytic enantioselective Catellani-type reaction for the synthesis of axially chiral biaryls.The chirality induction is solely governed by chiral norbornene ligand...This highlight summarizes a recent development of a catalytic enantioselective Catellani-type reaction for the synthesis of axially chiral biaryls.The chirality induction is solely governed by chiral norbornene ligand in the Pd mediated ortho C–H functionalization and ipso cross-coupling transformation.The preparative power of the methodology is demonstrated as a powerful manifold for the divergent synthesis of structurally diverse axially chiral biaryls and chiral fluorenols.展开更多
Objective: To develop a new high sensitivity, rapid and simple mycobacterium tuberculosis DNA detection method using fluorescence polarization technology. Methods: In our asymmetric PCR protocol, 100 times mole of TB-...Objective: To develop a new high sensitivity, rapid and simple mycobacterium tuberculosis DNA detection method using fluorescence polarization technology. Methods: In our asymmetric PCR protocol, 100 times mole of TB-R primer was added than in the usual symmetric PCR to get enough single strands PCR product. The probe TB-5′-TAMRA and PCR products were mixed in a tube and incubate for 5-15 min at 46 ℃.The polarization (mp) was measured using victor2 Multilabel Plate Reader. Results: Asymmetric and symmetric PCR products were analyzed by the FP method. Asymmetric PCR products are detected more sensitively than symmetric ones. The polarization values of probe associated with asymmetric products were much higher than with symmetric products. Conclusion: This fluorescence polarization assay in conjunction with asymmetric PCR is a powerful and widely applicable method for the rapid and sensitive detection of micro-organisms in clinical laboratories.展开更多
A new proline catalyst, namely (N'-benzyl-N'-D-prolyl)-trans-4-hydroxy-L-proline hydrazide, has been prepared and proved to be a superior catalyst for the asymmetric aldol reaction of cyclohexanone and aromatic al...A new proline catalyst, namely (N'-benzyl-N'-D-prolyl)-trans-4-hydroxy-L-proline hydrazide, has been prepared and proved to be a superior catalyst for the asymmetric aldol reaction of cyclohexanone and aromatic aldehydes, affording up to 98 : 2 dr and 98% ee.展开更多
基金Financial support from the National Natural Science Foundation of China (No. 21772046)the Recruitment Program of Global Experts(1000 Talents Plan)+1 种基金the Natural Science Foundation of Fujian Province(No. 2016J01064)Program of Innovative Research Team of Huaqiao University (No. Z14X0047)are gratefully acknowledged
文摘This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids(CPAs), a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral molecules. In the past years, different kinds of chiral phosphoric acids have been designed and developed into a privileged class of catalysts in asymmetric synthesis. A number of remarkable achievements have been made by many groups around the world. Due to length limitation, this review only summarizes those works published from January 2016 to November 2017. Meanwhile, catalytic systems which combine metal catalysts and chiral phosphoric acids will not be discussed in this review.
基金Project supported by the National Natural Science Foundation of China(No.29672004).
文摘The asymmetric reaction of the chiron 2(5H)-furanones (4a-4c) with the Homer-Emmons reagents (5a-5b) has been investigated. The newly chiral organophosphorus derivatives 6 and 7 were obtained using the phosphoryl-stabilized carbanion as a building block in DMSO under mild conditions. Through the asymmetric introduction, the Horner-Emmons reagent could be transformed to a chiral building block to afford the novel functionalized phosphorus derivatives. The structures of the synthesized compounds 6 and 7 were identified on the basis of their elementary and spectroscopic data, such as IR, 1H NMR, 13C NMR, MS and X-ray crystallography. These results provided a valuable approach to the synthesis of potentially interesting chiral organophosphorus derivatives and probing their biological activities.
文摘For the first time, synthetic dipeptides were applied to the catalysis of asymmetric Reformatsky reaction. Review in this domain & factors influencing enantioselectivity were discussed.
文摘MBHA resin-supported tripeptide catalyst system containing L-proline unit has been developed for use in the direct asymmetric aldol reaction of acetone and aldehydes, which afford the corresponding products with satisfactory isolated yields and enantiomeric excesses. 2009 Hong Bin Zou. Published by E]sevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金the National Natural Science Foundation of China(20472033)the Ph.D.Programs of Ministry of Education of China(No.20020055002)for generous financial support for our programs.
文摘Chiral activated alkene, L-menthyl acrylate and (+)-N-α-phenylethyl acrylamide, induced asymmetric Baylis-HiUman reaction of aromatic aldehydes was realized at 25℃ for 7 days in Me3N/H2O/solvent homogeneous medium. The corresponding Baylis-Hillman adducts were obtained in good chemical yield with moderate to excellent diastereoselectivity (up to 99% de).
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5-(1-Menthyloxy)-2(5-H)-furanone is used as s chiral dipolarophile for thermal asymmetric 1,3-dipolar cycloaddition reaction with C-phenyl-N-phenyl nitrone to give the diastereomerically pure cycloaddition product.
基金supported by the National Natural Science Foundation of China (No.60878056)the Doctoral Foundation of Xi’an Jiaotong University (DFXJTU2004-12)
文摘Objective To explore the optimal primer ratio and concentration of asymmetric polymerase chain reaction (A-PCR) in producing hepatitis B virus (HBV) single-stranded DNA (ssDNA) for pyrosequencing. Methods A-PCR was carried out to generate HBV ssDNA with forward to reverse primers of different ratios (50∶1, 100∶1) and concentrations (13.0 pmol/25μL and 0.14 pmol/25μL, 19.5 pmol/25μL and 0.21 pmol/25μL), and the product yield and quality were compared respectively. Results The forward to reverse primer ratio of 50∶1 provided better yield and concentration of 19.5 pmol/25μL and 0.21 pmol//25μL generated a clearer band. Conclusion A simple and feasible method to produce HBV ssDNA for pyrosequencing in batch is established.
基金the funding support of the National Key R&D Program of China(No.2021YFF0701601)NSFC(Nos.22031004 and 21921003)+1 种基金Shanghai Municipal Education Commission(No.20212308)Science and Technology Commission of Shanghai Municipality(No.23ZR1404800).
文摘Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantioselective annulation of SCBs with terminal alkynes remains a challenge.Herein,we report a rhodium-catalyzed asymmetric annulation reaction of SCBs with terminal alkynes,which relies on the newly identified chiral sulfinamide phosphine ligand Ming-Phos.This catalytic system exhibits unique effects under mild conditions,leading to the direct synthesis of structurally diverse chiral silacycles in moderate to good yields with high enantioselectivities(up to 95%ee).
基金This work was supported by the National Natural Science Foundation of China(21772029,21801051,21961006,22071036,82360589,81360589)The 10 Talent Plan(Shicengci)of Guizhou Province([2016]5649)+5 种基金the Guizhou Province Returned Oversea Student Science and Technology Activity Program[(2014)-2]the Science and Technology Department of Guizhou Province([2018]2802,[2019]1020)the Program of Introducing Talents of Discipline to Universities of China(111 Program,D20023)at Guizhou University,Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules,Department of Education,Guizhou Province[Qianjiaohe KY(2020)004]the Guizhou Province First-Class Disciplines Project[(Yiliu Xueke Jianshe Xiangmu)-GNYL(2017)008]Guizhou University of Traditional Chinese Medicine(China),and Guizhou University.
文摘An N-heterocyclic carbene(NHC)-catalyzed enantioselective Mannich reaction of the remoteγ-carbon of cyclopropylcarbaldehydes is disclosed for the first time.Diastereo-and enantiomerically enriched multicyclicδ-lactam compound is afforded as the main product from 8 possible stereo-specific isomers through dynamic kinetic asymmetric transformation(DYKAT)processes.Multiple chiral functional molecules can be afforded from the lactam products through simple protocols with retentions of the optical purities.
基金supports from the National Key R&D Program of China(2021YFA1200101 and 2022YFE0128700)the National Natural Science Foundation of China(22150013 and 21933001)+2 种基金the New Cornerstone Science Foundation through the XPLORER PRIZEthe Natural Science Foundation of Beijing(2222009)“Frontiers Science Centre for New Organic Matter”at Nankai University(63181206).
文摘Chirality,as the symmetric breaking of molecules,plays an essential role in physical,chemical and especially biological processes,which highlights the accurate distinction among heterochiralities as well as the precise preparation for homochirality.To this end,the well-designed structure-specific recognizer and catalysis reactor are necessitated,respectively.However,each kind of target molecules requires a custom-made chiral partner and the dynamic disorder of spatial-orientation distribution of molecules at the ensemble level leads to an inefficient protocol.In this perspective article,we developed a universal strategy capable of realizing the chirality detection and control by the external symmetry breaking based on the alignment of the molecular frame to external stimuli.Specifically,in combination with the discussion about the relationship among the chirality(molecule),spin(electron)and polarization(photon),i.e.,the three natural symmetry breaking,single-molecule junctions were proposed to achieve a single-molecule/event-resolved detection and synthesis.The fixation of the molecular orientation and the CMOS-compatibility provide an efficient interface to achieve the external input of symmetry breaking.This perspective is believed to offer more efficient applications in accurate chirality detection and precise asymmetric synthesis via the close collaboration of chemists,physicists,materials scientists,and engineers.
基金the National Natural Science Foundation of China(Nos.20842007,30600163)Natural Science Basic Research Plan in Shaanxi Province of China(No.SJ08-ZT02) for financial support.
文摘Cinchonine was employed as backbone for the synthesis of novel phosphite compounds with diol substituents. These monophosphinites were provided in one pot with the yields ranged from 63% to 75%. Their structures were confirmed by NMR spectroscopy and HRMS. C 2009 Sheng Yong Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘Cinchonine alkaloid catalyzed enantioselective methanolysis of six 4-substituted 2-phenyl-5(4H)-oxazolones to (S)-methyl N-benzoyl-alpha-amino acid esters with 10-33% e.e and 72-81% yield.
文摘An efficient asymmetric domino reaction of amino aldehyde to β,γ-unsaturated a-keto esters was achieved by using trans-perhydroindolic acid ld as a chiral organocatalyst with excellent asymmetric behavior. Under the opti- mal reaction conditions, products with more than 99% de and up to 93% ee were obtained in high chemical yield (up to 98%) for a series of β,γ-unsaturated a-keto esters. The methodology provided an efficient route to dihydro- pyran derivatives containing many substituent groups (including amino groups).
基金the National Natural Science Foundation of China (No. 21572233)the Strategic Priority Research Program of Chinese Academy of Sciences(No. XDB12010400) for financial supports
文摘Tetrahydrobenzo[5]helicenediol(THB-[5]HDIOL) derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas(LLB) aldol reactions of bulky aldehyde substrates was described. It was found that with dibromo-substituted helical diols P-4 a/M-4 a as additives, the prolinecatalyzed LLB aldol reaction of 9-anthraldehyde and acetone gave the product in 83% yield and 99% ee.Transition state models revealed an edge-to-face p-p stacking between the anthracenyl group in TS(R)and the phenyl group of the additive, which might result in the high enantioselectivity.
基金support by the NSFC(No.21402065)the start-up fund of Shanghai Institute of Technology is gratefully acknowledged.
文摘The 4,5-methano-L-proline was used as chiral organocatalysts in direct asymmetric aldol reactions.Under the optimal conditions,excellent enantioselectivities(up to 99%ee)were obtained with high chemical yields(up to 95%)for a series of aldehydes using only 5 mol%catalyst loading.To show the practicality of the method,the reaction was tested at a large scale.The reaction was complete in 16 h,and the aldol product was obtained in 86%yield and 93%ee.
基金Financial support was provided by the National Instittue of General Medical Sciences(No.5R01GM125920-04).
文摘This highlight summarizes a recent development of a catalytic enantioselective Catellani-type reaction for the synthesis of axially chiral biaryls.The chirality induction is solely governed by chiral norbornene ligand in the Pd mediated ortho C–H functionalization and ipso cross-coupling transformation.The preparative power of the methodology is demonstrated as a powerful manifold for the divergent synthesis of structurally diverse axially chiral biaryls and chiral fluorenols.
文摘Objective: To develop a new high sensitivity, rapid and simple mycobacterium tuberculosis DNA detection method using fluorescence polarization technology. Methods: In our asymmetric PCR protocol, 100 times mole of TB-R primer was added than in the usual symmetric PCR to get enough single strands PCR product. The probe TB-5′-TAMRA and PCR products were mixed in a tube and incubate for 5-15 min at 46 ℃.The polarization (mp) was measured using victor2 Multilabel Plate Reader. Results: Asymmetric and symmetric PCR products were analyzed by the FP method. Asymmetric PCR products are detected more sensitively than symmetric ones. The polarization values of probe associated with asymmetric products were much higher than with symmetric products. Conclusion: This fluorescence polarization assay in conjunction with asymmetric PCR is a powerful and widely applicable method for the rapid and sensitive detection of micro-organisms in clinical laboratories.
文摘A new proline catalyst, namely (N'-benzyl-N'-D-prolyl)-trans-4-hydroxy-L-proline hydrazide, has been prepared and proved to be a superior catalyst for the asymmetric aldol reaction of cyclohexanone and aromatic aldehydes, affording up to 98 : 2 dr and 98% ee.