A facile,rapid and efficient method for the synthesis of molecular tweezers containing chiral unsymmetrical urea unit in solvent- free conditions using microwave was reported.
An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction t...An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process.展开更多
A novel type of molecular tweezers with different chiral center and cleft has been designed and prepared by using α- hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position....A novel type of molecular tweezers with different chiral center and cleft has been designed and prepared by using α- hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position. Their structures were elucidated by ^1H NMR, FTIR and elemental analysis. Their recognition properties for various D/L-amino acid methyl esters were also investigated. The preliminary results indicated that these chiral single-armed molecular tweezers exhibited good recognition ability for D/L-amino acid methyl esters with high association constant （up to 5.24 × 10^3 L mol^-1）.展开更多
A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H ...A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.展开更多
A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis ...A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis of the molecular tweezers receptors. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.展开更多
A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra an...A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra and elemental analysis. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.展开更多
A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high s...A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high selectivity toward F^- over Cl^-, Br^-, I^-, AcO^-, H2PO4^-.展开更多
Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes recognition.The syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordinati...Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes recognition.The syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordination,gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene solution.It exhibits distinct binding selectivity towards C_(60)over C_(70).Moreover,the fullerene recognition capacity can be adequately suppressed by importing H_(2)PO_(4)^(-)to competitively capture Zn(Ⅱ)along with syn-anti conformational conversion.Subsequently,the molecular tweezer regenerated to bind the fullerene by introducing the Ca^(2+)into the system.Significantly,the association-disassociation process can be switched reversibly and repeatedly.展开更多
Diazocines,a type of photoswitch molecules,are distinguished by their unique conformation and photochromic properties.Molecular engineering of diazocines,especially theπ-extended ones,remains challenging due to limit...Diazocines,a type of photoswitch molecules,are distinguished by their unique conformation and photochromic properties.Molecular engineering of diazocines,especially theπ-extended ones,remains challenging due to limited synthetic methods.Here,we developed threeπ-fused diazocines(BAZO-1,BAZO-2,and BAZO-3)via Bischler–Napieralski cyclization.Their isomerizations(Z⇆E)were switchable under visible light sources(427 and 630 nm).The size of theirπ-extension exerted a significant influence on the isomerization process,whereby the biggest fourfold ring-closure diazocine(BAZO-3)showed the fastest conversion rate(Z→E).Notably,the half-life(t1/2)of the E isomer of BAZO-3 was 14.6 times higher than that of the twofold ring-closure BAZO-1.Thus,BAZO-3 acted as a molecular tweezer based on double N-embedded pyrene units,allowing it to bind to pyrene through supramolecular interactions.This work may pave the way for designing novel photoswitches with long half-lives and lightcontrolled properties.展开更多
Amyloid-βpeptide(Aβ)oligomers,characteristic symptom of Alzheimer’s disease(AD),have been identified as the most neurotoxic species and significant contributors to neurodegeneration in AD.However,due to their trans...Amyloid-βpeptide(Aβ)oligomers,characteristic symptom of Alzheimer’s disease(AD),have been identified as the most neurotoxic species and significant contributors to neurodegeneration in AD.However,due to their transient and heterogeneous nature,the high-resolution structures and exact pathogenic processes of Aβ oligomers are currently unknown.Using light-controlled molecular tweezers(LMTs),we describe a method for precisely capturing specific Aβ oligomers produced from synthetic Aβ and AD animal models.Light irradiation can activate LMTs,which are composed of two Aβ-targeting pentapeptides(KLVFF)motifs and a rigid azobenzene(azo)derivative,to form a tweezer-like cis configuration that preferentially binds to specific oligomers matching the space of the tweezers via multivalent interactions of KLVFF motifs with the oligomers.Surprisingly,cis-LMTs can immobilize the captured oligomers in transgenic Caenorhabditis elegans under light irradiation.The LMTs may serve as spatiotemporally controllable molecular tools to extract specific native oligomers for the structure and function studies via reversible photoisomerization,which would improve the understanding of the toxic mechanisms of Aβoligomers and development of oligomer-targeted diagnosis and therapy.展开更多
文摘A facile,rapid and efficient method for the synthesis of molecular tweezers containing chiral unsymmetrical urea unit in solvent- free conditions using microwave was reported.
基金supported by the Doctors Innovation Foundation of Southwest University for Nationalities(No.08NBS002).
文摘An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process.
基金support from National Natural Science Foundation of China(No.20272038).
文摘A novel type of molecular tweezers with different chiral center and cleft has been designed and prepared by using α- hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position. Their structures were elucidated by ^1H NMR, FTIR and elemental analysis. Their recognition properties for various D/L-amino acid methyl esters were also investigated. The preliminary results indicated that these chiral single-armed molecular tweezers exhibited good recognition ability for D/L-amino acid methyl esters with high association constant （up to 5.24 × 10^3 L mol^-1）.
文摘A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.
基金We are very grateful to the National Natural Science Foundation of China(project:No.29772024)for the financial support.
文摘A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis of the molecular tweezers receptors. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.
文摘A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra and elemental analysis. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.
基金We are very grateful to the National Natural Science Foundation of China(No.20272038)for the financial support.
文摘A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high selectivity toward F^- over Cl^-, Br^-, I^-, AcO^-, H2PO4^-.
基金the financial support of the National Natural Science Foundation of China(No.21801060)Natural Science Foundation of Hebei Province(Nos.B2019205172,226Z1501G)+1 种基金China Postdoctoral Science Foundation(No.2020TQ0087)the support from the National Demonstration Center for Experimental Chemistry Education of Hebei Normal University。
文摘Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes recognition.The syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordination,gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene solution.It exhibits distinct binding selectivity towards C_(60)over C_(70).Moreover,the fullerene recognition capacity can be adequately suppressed by importing H_(2)PO_(4)^(-)to competitively capture Zn(Ⅱ)along with syn-anti conformational conversion.Subsequently,the molecular tweezer regenerated to bind the fullerene by introducing the Ca^(2+)into the system.Significantly,the association-disassociation process can be switched reversibly and repeatedly.
基金supported financially by the Singapore Agency for Science,Technology,and Research(A*STAR)under its Manufacturing,Trade and Connectivity Individual Research Grant(IRG,grant no.M22K2c0077)National Natural Science Foundation of China(NSFC,grant no.21975178).
文摘Diazocines,a type of photoswitch molecules,are distinguished by their unique conformation and photochromic properties.Molecular engineering of diazocines,especially theπ-extended ones,remains challenging due to limited synthetic methods.Here,we developed threeπ-fused diazocines(BAZO-1,BAZO-2,and BAZO-3)via Bischler–Napieralski cyclization.Their isomerizations(Z⇆E)were switchable under visible light sources(427 and 630 nm).The size of theirπ-extension exerted a significant influence on the isomerization process,whereby the biggest fourfold ring-closure diazocine(BAZO-3)showed the fastest conversion rate(Z→E).Notably,the half-life(t1/2)of the E isomer of BAZO-3 was 14.6 times higher than that of the twofold ring-closure BAZO-1.Thus,BAZO-3 acted as a molecular tweezer based on double N-embedded pyrene units,allowing it to bind to pyrene through supramolecular interactions.This work may pave the way for designing novel photoswitches with long half-lives and lightcontrolled properties.
基金National Natural Science Foundation of China,Grant/Award Numbers:21771105,22377053Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20170103The Six Talent Peaks Project in Jiangsu Province,Grant/Award Number:SWYY-043。
文摘Amyloid-βpeptide(Aβ)oligomers,characteristic symptom of Alzheimer’s disease(AD),have been identified as the most neurotoxic species and significant contributors to neurodegeneration in AD.However,due to their transient and heterogeneous nature,the high-resolution structures and exact pathogenic processes of Aβ oligomers are currently unknown.Using light-controlled molecular tweezers(LMTs),we describe a method for precisely capturing specific Aβ oligomers produced from synthetic Aβ and AD animal models.Light irradiation can activate LMTs,which are composed of two Aβ-targeting pentapeptides(KLVFF)motifs and a rigid azobenzene(azo)derivative,to form a tweezer-like cis configuration that preferentially binds to specific oligomers matching the space of the tweezers via multivalent interactions of KLVFF motifs with the oligomers.Surprisingly,cis-LMTs can immobilize the captured oligomers in transgenic Caenorhabditis elegans under light irradiation.The LMTs may serve as spatiotemporally controllable molecular tools to extract specific native oligomers for the structure and function studies via reversible photoisomerization,which would improve the understanding of the toxic mechanisms of Aβoligomers and development of oligomer-targeted diagnosis and therapy.
