Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Synthesis of C₇₀-fragment buckybowls bearing alkoxy substituents.

ABSTRACT: Buckybowls bearing a C₇₀ fragment having two alkoxy groups were synthesized and their structural and optical properties were investigated by single crystal X-ray analysis and UV-vis spectroscopy. In the synthesis of dioxole derivative 5b, the regioisomer 5c was also produced. The yield of 5c was increased by increasing the reaction temperature, indicating that the rearrangement might involve the equilibrium between the Pd(IV) intermediates through C-H bond activation.

SUBMITTER: Yakiyama Y

PROVIDER: S-EPMC7176931 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Synthesis of C70-fragment buckybowls bearing alkoxy substituents.

Yakiyama Yumi Y Hishikawa Shota S Sakurai Hidehiro H

Beilstein journal of organic chemistry 20200415

Buckybowls bearing a C70 fragment having two alkoxy groups were synthesized and their structural and optical properties were investigated by single crystal X-ray analysis and UV-vis spectroscopy. In the synthesis of dioxole derivative 5b, the regioisomer 5c was also produced. The yield of 5c was increased by increasing the reaction temperature, indicating that the rearrangement might involve the equilibrium between the Pd(IV) intermediates through C-H bond activat ...[more]

PMID: 32362946

Similar Datasets

Synthesis, crystal structure, self-assembly of C60 derivatives bearing rigid pyridine substituents.

Project description:Microstructures of fullerene derivatives formed via self-assembly strategy facilitate the versatile applications of these zero-dimensional molecules. However, the accurate elucidation of formation mechanism of fullerene microstructures is a challenge issue. A novel fullerene derivative 2 with rigid pyridine substituent was synthesized and characterized by X-ray crystallography. Using the strategy of liquid-liquid interfacial precipitation, self-assembly of 2 affords a micrometer-sized flowerlike and a discoid morphology. Based on the crystal packing of 2, the proper formation mechanism of different morphologies was proposed. Meanwhile, the photoelectrochemical properties of different morphologies of 2 was also unveiled.

| S-EPMC9059989 | biostudies-literature

Synthesis of 2-Deoxyglycosides Bearing Free Hydroxyl Substituents on the Glycosyl Donor.

Project description:Recent efforts in the field of carbohydrate chemistry have focused on the site- and stereocontrolled synthesis of O-glycosides derived from acceptors bearing multiple hydroxyl substituents. By comparison, there are few examples of the site-selective synthesis of O-glycosides bearing free hydroxyl substituents on the donor reagent. Here, we report the application of an umpolung glycosylation strategy to the synthesis of O-glycosides derived from donors bearing free hydroxyl substituents. The reaction proceeds via prior deprotonation of one or more free hydroxyl groups on a thiophenylglycoside donor, reductive lithiation to generate an anomeric anion intermediate, and addition of this anion to an alkyl 2-(2-methyltetrahydropyranyl) peroxide. By this approach, α-linked glycosides were obtained in 39-84% yields and with >50:1 α/β selectivities. In many instances, β-linked products could be obtained by thermal equilibration of the anomeric anion intermediate (selectivities = 3.8-8:1 β/α; yields = 33-68%). The strategy is applicable to polyhydroxyl donors bearing up to three free hydroxyl groups, N-acylated carbohydrates, and the single-flask syntheses of oligosaccharides.

| S-EPMC9511991 | biostudies-literature

Cycloadditions of 1,2,3-Triazines Bearing C5-Electron Donating Substituents: Robust Pyrimidine Synthesis.

Project description:The examination of the cycloaddition reactions of 1,2,3-triazines 17-19, bearing electron-donating substituents at C5, are described. Despite the noncomplementary 1,2,3-triazine C5 substituents, amidines were found to undergo a powerful cycloaddition to provide 2,5-disubstituted pyrimidines in excellent yields (42-99%; EDG = SMe > OMe > NHAc). Even select ynamines and enamines were capable of cycloadditions with 17, but not 18 or 19, to provide trisubstituted pyridines in modest yields (37-40% and 33% respectively).

| S-EPMC4546508 | biostudies-literature

Cross-Linked Metathesis Polynorbornenes Based on Nadimides Bearing Hydrocarbon Substituents: Synthesis and Physicochemical Properties.

Project description:Metathesis homo- and copolymerization of bifunctional monomers bearing two norbornene moieties was studied. The monomers were synthesized from cis-5-norbornene-exo-2,3-dicarboxylic anhydride and various diamines (hexamethylenediamine, decamethylenediamine, 1R,3S-isophoronediamine). The metathesis homopolymerization of these bis(nadimides) in the presence of the second-generation Grubbs catalyst afforded glassy cross-linked polymers in more than 90% yields. The metathesis copolymerization of the bis(nadimides) and a monofunctional norbornene derivative containing the β-pinene fragment also resulted in insoluble cross-linked polymers in nearly quantitative yields. The structures and purity of the synthesized polymers were confirmed via IR spectroscopy and CP/MAS NMR spectroscopy. Conditions for the fabrication of mechanically strong solution-cast thin films based on copolymers synthesized from the comonomers mentioned above were determined by varying the content of the cross-linking agent. It was shown that the films made in this way are stable in a range of organic solvents and could be useful as semipermeable or membrane materials for use in liquid organic media. The permeability of the polymer films in question to 1-phenylethanol and mandelic acid was studied. The results obtained are discussed along with the data from the DSC, TGA, and powder X-ray diffraction studies of the properties of the synthesized metathesis homo- and copolymers.

| S-EPMC11436105 | biostudies-literature

Synthesis of the C1-C52 fragment of amphidinol 3, featuring a beta-alkoxy alkyllithium addition reaction.

Project description:An advanced intermediate for the synthesis of amphidinol 3 has been prepared. A cross-metathesis reaction was used to couple the C1-C12 and C13-C26 segments. An unusual beta-alkoxy alkyllithium reagent was generated from this segment and added to a Weinreb amide to assemble the C1-C52 section of amphidinol 3. These compounds represent some of the most advanced intermediates reported to date for the synthesis of amphidinol 3.

| S-EPMC2496920 | biostudies-literature

as-Indaceno[3,2,1,8,7,6-ghijklm]terrylene as a near-infrared absorbing C70-fragment.

Project description:Carbon and hydrogen are fundamental components of organic molecules and a fascinating plethora of functions can be generated using these two elements. Yet, realizing attractive electronic structures only by using carbon and hydrogen remains challenging. Herein, we report the synthesis and properties of the C70 fragment as-indaceno[3,2,1,8,7,6-ghijklm]terrylene, which exhibits near-infrared (NIR) absorption (up to ca. 1300 nm), even though this molecule consists of only 34 carbon and 14 hydrogen atoms. A remarkably small highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap is confirmed by electrochemical measurement and theoretical calculations. Furthermore, as-indacenoterrylene is stable despite the absence of peripheral substituents, which contrasts with the cases of other NIR-absorbing hydrocarbons such as diradicaloids and antiaromatic molecules. The results of this study thus offer fundamental insights into the design of hydrocarbons with a small band gap.

| S-EPMC7400669 | biostudies-literature

Zwitterionic DNA: enzymatic synthesis of hypermodified DNA bearing four different cationic substituents at all four nucleobases.

Project description:We designed and synthesized a set of four 2'-deoxyribonucleoside 5'-O-triphosphates (dNTPs) bearing cationic substituents (protonated amino, methylamino, dimethylamino and trimethylammonium groups) attached to position 5 of pyrimidines or position 7 of 7-deazapurines through hex-1-ynyl or propargyl linker. These cationic dNTPs were studied as substrates in enzymatic synthesis of modified and hypermodified DNA using KOD XL DNA polymerase. In primer extension (PEX), we successfully obtained DNA containing one, two, three, or (all) four modified nucleotides, each bearing a different cationic modification. The cationic dNTPs were somewhat worse substrates compared to previously studied dNTPs bearing hydrophobic or anionic modifications, but the polymerase was still able to synthesize sequences up to 73 modified nucleotides. We also successfully combined one cationic modification with one anionic and two hydrophobic modifications in PEX. In polymerase chain reaction (PCR), we observed exponential amplification only in the case of one cationic modification, while the combination of more cationic nucleotides gave either very low amplification or no PCR product. The hypermodified oligonucleotides prepared by PEX were successfully re-PCRed and sequenced by Sanger sequencing. Biophysical studies of hybridization, denaturation, and circular dichroism spectroscopy showed that the presence of cationic modifications increases the stability of duplexes.

| S-EPMC11890062 | biostudies-literature

Superanionic DNA: enzymatic synthesis of hypermodified DNA bearing four different anionic substituents at all four nucleobases.

Project description:We designed and synthesized a set of four 2'-deoxyribonucleoside 5'-O-triphosphates (dNTPs) derived from 5-substituted pyrimidines and 7-substituted 7-deazapurines bearing anionic substituents (carboxylate, sulfonate, phosphonate, and phosphate). The anion-linked dNTPs were used for enzymatic synthesis of modified and hypermodified DNA using KOD XL DNA polymerase containing one, two, three, or four modified nucleotides. The polymerase was able to synthesize even long sequences of >100 modified nucleotides in a row by primer extension (PEX). We also successfully combined two anionic and two hydrophobic dNTPs bearing phenyl and indole moieties. In PCR, the combinations of one or two modified dNTPs gave exponential amplification, while most of the combinations of three or four modified dNTPs gave only linear amplification in asymmetric PCR. The hypermodified ONs were successfully re-PCRed and sequenced by Sanger sequencing. Biophysical studies including hybridization, denaturation, CD spectroscopy and molecular modelling and dynamics suggest that the presence of anionic modifications in one strand decreases the stability of duplexes while still preserving the B-DNA conformation, whilst the DNA hypermodified in both strands adopts a different secondary structure.

| S-EPMC10681718 | biostudies-literature

Tetraphenylethene Derivatives Bearing Alkylammonium Substituents: Synthesis, Chemical Properties, and Application as BSA, Telomere DNA, and Hydroxyl Radical Sensors.

Project description:Tetraphenylethene derivatives (TPEs) are used as luminescence probes for the detection of metal ions and biomolecules. These sensors function by monitoring the increase in the photoluminescence (PL) intensity of the TPEs resulting from aggregation-induced emission (AIE) upon interaction with the analytes. The AIE behavior of the sensors was investigated by measuring their PL. In this study, PL, PL lifetime, and confocal laser scanning microscopy measurements were carried out as part of our in-depth investigation of AIE behavior of TPEs for the detection of biomolecules and radical species. We used 1,1,2,2-tetrakis(4-((trimethylammonium)alkoxy)phenyl)tetraphenylethene tetrabromide (TPE-C(m)N+Me3Br-, m = 2, 4, and 6, where m denotes the number of methylene groups in the alkyl chain) and TPE-C(m)N+Me3TCNQ-• (TCNQ-• is the 7,7',8,8'-tetracyanoquinodimethane anion radical) as luminescent probes for the detection of bovine serum albumin (BSA), DNA, and the hydroxyl radical (•OH) generated from Fenton's reagent. The sensing performance of TPE-C(m)N+Me3Br- for BSA and DNA was found to depend on the length of the alkyl chains (m). UV-vis and PL measurements revealed that the responses of TPE-C(m)N+Me3Br- and TPE-C(4)N+TCNQ-• to Fenton's reagent depended on the solvent. The electrochemical properties of the TPE derivatives prepared in this study were additionally investigated via cyclic voltammetry.

| S-EPMC10419492 | biostudies-literature

Synthesis and Fluorescent Properties of Multi-Functionalized C70 Derivatives of C70(OCH3)10[C(COOEt)2] and C70(OCH3)10[C(COOEt)2]2.

Project description:Due to the partially reduced π-conjugation of the fullerene cage, multi-functionalized fullerene derivatives exhibit remarkable fluorescent properties compared to pristine fullerenes, which have high potential for application in organic light-emitting diodes (OLEDs). In this study two multi-functionalized C70 derivatives, C70(OCH3)10[C(COOEt)2] and C70(OCH3)10[C(COOEt)2]2, with excellent fluorescence properties, were designed and synthesized. Compared with C70(OCH3)10 containing a single kind of functional group, both the C70(OCH3)10[C(COOEt)2] and C70(OCH3)10[C(COOEt)2]2 exhibited enhanced fluorescence properties with blue fluorescence emission. The fluorescence quantum yields of the C70(OCH3)10[C(COOEt)2] and C70(OCH3)10[C(COOEt)2]2 were 1.94% and 2.30%, respectively, which were about ten times higher than that of C70(OCH3)10. The theoretical calculations revealed that the multi-functionalization of the C70 increased the S1-T1 energy gap, reducing the intersystem crossing efficiency, resulting in the higher fluorescence quantum yield of the C70 derivatives. The results indicate that multi-functionalization is a viable strategy to improve the fluorescence of fullerene derivatives.

| S-EPMC9099540 | biostudies-literature