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1.
Org Lett ; 26(13): 2552-2557, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38527028

RESUMEN

Selective functionalization of fullerenes is an important but challenging topic in fullerene chemistry and synthetic chemistry. Here we present the first example of catalytic system-controlled regioselective 1,2- and 1,4-addition reactions for the flexible and efficient synthesis of novel 1,2- and 1,4-carbocycle-fused fullerenes via a palladium-catalyzed decarboxylative carboannulation process.

2.
Org Lett ; 26(7): 1432-1436, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38350149

RESUMEN

An interrupted N-heterocyclic carbene-catalyzed radical coupling strategy is disclosed for efficient alkylation and arylation of [60]fullerene. This novel and general strategy bridges the gap between organocatalytic radical cross-coupling and functionalization of fullerenes. Readily available feedstocks, remarkably broad substrate scope and functional group compatibility, and convenient late-stage nanomodification of complex molecules make this strategy with incomparable diversity and practicality in the synthesis of monoalkylated and -arylated fullerenes.

3.
J Org Chem ; 88(18): 13076-13088, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37651613

RESUMEN

An unexpected copper-mediated radical-induced ring-opening relay cascade carboannulation reaction of [60]fullerene with cyclobutanone oxime esters is presented for the preparation of various Cl-/Br-incorporated [60]fullerene-fused cyclopentanes. The unique relay cascade transformation uses inexpensive copper salts as promoters and halogen sources and features simple redox-neutral conditions and a broad substrate scope, providing a practical access to a class of novel five-membered carbocycle-fused fullerenes.

4.
Org Lett ; 24(49): 9102-9106, 2022 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-36475859

RESUMEN

Herein, a concise and robust approach for the highly efficient assembly of [60]fullerene-fused tricyclic scaffolds has been developed through a palladium-catalyzed cascade [2 + 2 + 2] annulation process. Diverse tricyclic scaffolds incorporating various ring sizes (6-19 membered) and types (carbocycles and N- and O-heterocycles) can be expediently constructed in a single-step transformation.


Asunto(s)
Fulerenos , Paladio , Catálisis
5.
Org Lett ; 24(20): 3691-3695, 2022 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-35576614

RESUMEN

A novel N-heterocyclic carbene-catalyzed three-component umpolung hydroalkylation of [60]fullerene with 4-(chloromethyl)-benzaldehydes/α,ß-unsaturated aldehydes and alcohols/thioalcohols has been developed for the flexible and efficient preparation of diverse monoalkylated hydrofullerenes. Organic catalysis, broad substrate scope, excellent functional group tolerance, and products with high diversity and complexity levels are attractive features of this protocol.

6.
J Org Chem ; 87(5): 3104-3113, 2022 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-35078312

RESUMEN

Herein, an unprecedented transformation of [60]fullerene with ferrocene compounds giving access to various [60]fullerene-fused bicyclo[2.2.1]hept-5-enes is presented. In the presence of an acid, ferrocene compounds undergo an unusual dissociation process and serve as Diels-Alder diene equivalents to react with [60]fullerene for the selective construction of a class of novel fullerene-fused bridged carbocyclic derivatives. The reaction is easy to perform and has a wide substrate scope as well as excellent functional group compatibility, representing a new application of ferrocene compounds in synthetic chemistry.

7.
J Hazard Mater ; 424(Pt A): 127301, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34597930

RESUMEN

A key matter in heavy metal removal technology is to develop the adsorbents with efficient adsorption sites. In this study, an oxygen-rich covalent organic framework (JUC-505) was functionalized by carboxyl (-COOH) groups to form synergetic effects aiming for the removal of Cd(II) and Pb(II) ions. JUC-505-COOH shows a high Cd(II) uptake of 504 mg⋅g-1 surpassing most of the reported porous adsorbents. Meanwhile, the kinetics study shows a rapid adsorption process at a high initial concentration (100 mg⋅L-1), and the equilibrium can be reached within 5 min. We investigated the adsorption mechanism in-depth by density functional theory calculations, proving the synergistic effects of surface complexation and hydrogen-bond, which are from the post-modified -COOH groups and the in-situ oxygen atoms of JUC-505, respectively. Moreover, under the interference of common ions in natural water, the removal efficiency of Cd(II) is almost insusceptible, which sheds lights on the potential for the application in the natural water purification. In addition, the Pb(II) uptake (559 mg⋅g-1) and the adsorption kinetics also surpass most of the reported porous adsorbents.

8.
Org Lett ; 23(5): 1775-1781, 2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33576632

RESUMEN

The first example of metal-free-catalyzed multicomponent annulation reaction of [60]fullerene has been developed for concise and efficient construction of novel [60]fullerene-fused 1,2-tetrahydrocarbazoles. Using inexpensive and readily available I2 as a catalyst, [60]fullerene, ketones, and indoles undergo a formal [2+2+2] annulation process to conveniently assemble diverse 1,2-tetrahydrocarbazoles. Mechanistic studies indicate that this reaction proceeds through I2-promoted generation of a 3-vinylindole structure with the characteristics of a conjugated diene followed by cycloaddition to [60]fullerene.

9.
Chem Commun (Camb) ; 57(1): 49-52, 2021 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-33244545

RESUMEN

Herein a new, general and practical method for the spirocyclization of [60]fullerene through a palladium-catalyzed domino Heck/C-H activation reaction is presented. A wide range of novel [60]fullerene-fused spirocyclic derivatives can be easily and flexibly synthesized with a broad substrate scope and excellent functional-group tolerance. A plausible mechanism involving an alkyl Pd(ii) species as a key intermediate has been proposed.

10.
Org Lett ; 22(18): 7327-7332, 2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-32897079

RESUMEN

Herein an unprecedented iron(II)-catalyzed redox-neutral radical cascade reaction of [60]fullerene with γ,δ-unsaturated oxime esters is reported for the preparation of novel free (N-H) pyrrolidino[2',3':1,2]fullerenes. The transformation undergoes an intramolecular cyclization/intermolecular cyclization/oxidation/hydrolysis cascade, and features simple operation, broad substrate scope/high functional group compatibility as well as suitable for scale-up synthesis, providing a facile and practical access to a range of free pyrrolidino[2',3':1,2]fullerenes.

11.
Org Lett ; 21(16): 6461-6465, 2019 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-31373207

RESUMEN

Reported herein is a new copper-catalyzed N-H/C-H sequential relay oxidative radical carboannulation of [60]fullerene with C2-functionalized free indoles for the direct construction of novel [60]fullerene-fused tetrahydrocyclopenta[b]indoles. The transformation shows high regioselectivity and atom economy, broad substrate scope, and good functional group tolerance, providing an efficient and practical approach to access diversely substituted fullerene-fused polycyclic derivatives from simple hydrocarbons.

12.
Menopause ; 26(1): 94-102, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-29975282

RESUMEN

OBJECTIVE: In the present study, we aimed to characterize the pathological development of menopausal osteoporosis, as well as to explore potential biomarkers and metabolic pathways involved in osteoporosis. METHODS: Urine samples from 322 female participants categorized by menopause status and different bone conditions were collected and analyzed based on a gas chromatography-mass spectrometry (GC-MS) approach. Multivariate and univariate statistical analyses were carried out for urinary metabolomic profile characterization and comparison. RESULTS: Seventeen metabolites in the low bone mineral density (BMD) groups were clearly differentiated from those in normal BMD groups. Among these 17 differentiating metabolites, taurine, ß-alanine, and 5-hydroxycaproic acid were found to be potential biomarkers of osteoporosis. The taurine metabolic pathway and the ß-alanine metabolic pathway were found to be related to menopause and bone loss. CONCLUSIONS: Based on the GC-MS metabolomic platform, four typical pathological phases during the progression of postmenopausal osteoporosis were described. Several differentiating metabolites and metabolic pathways were found to be closely related to the pathology of postmenopausal osteoporosis. Our results provided a solid foundation for further studies on early diagnosis and pathomechanistic evaluation.


Asunto(s)
Densidad Ósea/fisiología , Metaboloma/fisiología , Osteoporosis Posmenopáusica/orina , Posmenopausia/orina , Premenopausia/orina , Adulto , Anciano , Análisis de Varianza , Biomarcadores/orina , Caproatos/orina , China , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Hidroxiácidos/orina , Persona de Mediana Edad , Osteoporosis Posmenopáusica/patología , Taurina/orina , beta-Alanina/orina
13.
Chem Commun (Camb) ; 54(95): 13331-13334, 2018 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-30351311

RESUMEN

Described here is the first example of solvent-promoted catalyst-free N-incorporation multicomponent domino reaction for the direct construction of novel π-extension [60]fullerene-fused dihydrocarbolines from simple hydrocarbons. This unprecedented transformation is proposed to proceed by a sequential N-incorporation/[4+2] cycloaddition/elimination process, involving multiple types of bond cleavage and formation in a single chemical operation. Mechanistic studies uncover that solvent is crucial for the success of the transformation, and multiple solvent-aided deprotonation and proton transfer are involved as key steps.

14.
Org Lett ; 20(16): 4801-4805, 2018 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-30052460

RESUMEN

The first umpolung strategy for the cycloacylation of fullerene using a N-heterocyclic carbene organocatalyst is reported. The coupling of [60]fullerene with different structural α,ß-unsaturated aldehydes efficiently furnishes interesting [60]fullerene-fused cyclopentan-1-ones or cyclohex-2-en-1-ones in good to excellent yields. This new reaction displays a wide substrate scope and excellent functional-group tolerance, and diverse substituents such as aryl, heteroaryl, alkenyl, alkyl, and ester can be installed by using the corresponding enals.

15.
J Org Chem ; 83(2): 862-870, 2018 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-29219312

RESUMEN

A novel and efficient Cu(I)/Ag(I)-mediated synergistic annulation reaction of [60]fullerene with diarylethanones, benzoylacetonitriles, and ß-dicarbonyl compounds has been developed for the direct construction of diverse disubstituted dihydrofuran-fused [60]fullerene derivatives. This transformation exhibits a remarkably broad substrate scope and functional group tolerance and provides a useful method to a scarce class of fullerene derivatives.

16.
Org Lett ; 18(16): 4044-7, 2016 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-27487008

RESUMEN

A transition-metal-free oxidative dehydrogenative coupling reaction has been developed for the direct construction of novel C60-fused tetrahydrocarbazoles, dibenzothiophenes, benzothiophenes, and dibenzofurans. This new carboannulation reaction features high atom economy, operational simplicity, broad substrate scope, and excellent functional-group tolerance and provides a convenient access to a scarce class of fullerene derivatives.

17.
Bioorg Med Chem Lett ; 26(19): 4720-4723, 2016 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-27575480

RESUMEN

Strontium fructose 1,6-diphosphate (FDP-Sr) is a new strontium-containing compound. The primary aim of this study was to clarify whether the structure component of FDP-Sr, FDP could benefit the protective effect of Sr (II) against oxidative stress induced apoptosis, and meanwhile to further explore the important role of Wnt/ß-catenin signaling in the anti-apoptosis effect of FDP-Sr in response to oxidative stress induced by H2O2 in an osteoblastic MC3T3-E1 cell line. Results showed that FDP-Sr could improve the osteoblastic differentiation under oxidative stress with induced cell proliferation and improved mineralization. The inhibition effect of FDP-Sr on cell apoptosis induced by H2O2 was proved by reduced reactive oxygen species production and activated caspase3. Under oxidative stress, mRNA and protein levels of phospho-ß-catenin reduced, while ß-catenin increased in the FDP-Sr treatment cell, leaded to the up-regulations of Runx2 and OPG at both mRNA and protein levels, finally improved the differentiation of osteoblasts. By the engagement of Wnt/ß-catenin pathway's inhibitor (XAV-939), the protective effects of FDP-Sr on osteoblastic differentiation against oxidative stress were repressed along with inhibited wnt/ß-catenin signaling and reduced mRNA and protein levels of Runx2 and OPG. In conclusion, FDP-Sr was demonstrated to protect osteoblast differentiation from oxidative damage induced by H2O2 through up-regulation of Wnt/ß-catenin signaling, and FDP in FDP-Sr was able to directly improve the oxidative stress injury through its ROS scavenging ability.


Asunto(s)
Formicinas/química , Estrés Oxidativo/efectos de los fármacos , Ribonucleótidos/química , Transducción de Señal , Proteínas Wnt/metabolismo , Células 3T3 , Animales , Ratones
18.
Mol Biosyst ; 12(7): 2265-75, 2016 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-27168060

RESUMEN

The present study describes for the first time, a metabolic profile reflecting the osteoporosis progression in 364 pre- and postmenopausal Chinese women using GC-MS. In order to accurately evaluate the dynamic changes of metabolites along with estrogen deficiency and osteoporosis progression, we divided these subjects into the following four groups: premenopausal women with normal bone mass density (BMD, group I), postmenopausal women with normal BMD (group II), postmenopausal women with osteopenia (group III) and postmenopausal women with osteoporosis (group IV), according to their menopause or low BMD status. Principal component analysis (PCA) and Partial least squares-discriminant analysis (PLS-DA) were used to evaluate the associations of metabolic changes with low BMD or estrogen deficiency. Twelve metabolites identified by the PLS-DA model were found to be able to differentiate low BMD groups from normal BMD groups. Of the 12 metabolites, five free fatty acids (LA, oleic acid, AA and 11,14-eicosadienoic acid) have the most potential to be used as osteoporosis biomarkers due to their better correlations with BMD, and high sensitivity and specificity in distinguishing the low BMD groups from the normal BMD groups calculated by the receiver operating characteristic curve (ROC). The lipid profile may be useful for osteoporosis prediction and diagnosis.


Asunto(s)
Pueblo Asiatico , Densidad Ósea , Menopausia , Metaboloma , Osteoporosis Posmenopáusica/metabolismo , Osteoporosis Posmenopáusica/patología , Vigilancia en Salud Pública , Absorciometría de Fotón , Adulto , Anciano , Biomarcadores , Resorción Ósea/metabolismo , China/epidemiología , Progresión de la Enfermedad , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Lípidos/sangre , Metabolómica/métodos , Persona de Mediana Edad , Osteoporosis Posmenopáusica/epidemiología , Curva ROC
19.
Chem Commun (Camb) ; 52(5): 982-5, 2016 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-26594033

RESUMEN

A novel Ag(I)-induced three-component annulation reaction of [60]fullerene with sulfonylhydrazones and nitriles has been developed for the efficient synthesis of diverse disubstituted [60]fullerene-fused dihydropyrroles. The reaction exhibits a broad substrate scope and excellent functional-group tolerance, and also allows for the synthesis of fullerene-bound macromolecules.

20.
Chem Commun (Camb) ; 51(64): 12775-8, 2015 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-26165985

RESUMEN

An unprecedented AgNO2-mediated novel transformation of sulfonylhydrazones with [60]fullerene to various fulleroisoxazolines has been developed. The new chemistry of sulfonylhydrazones involving the cleavage of the N-N bond in synthetic application is first disclosed. Silver nitrite acts as the reaction initiator and the oxygen source in this unique transformation. This reaction is easy to perform, and exhibits a remarkably wide substrate scope under mild conditions.

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