Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
J Org Chem ; 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39219441

RESUMO

An efficient photocatalytic protocol combining heterogeneous semiconductors as photocatalysts and NHPI as a redox reagent was disclosed. Under this protocol, 3-sulfonylquinolines were formed in up to 92% yield via a multicomponent radical cascade annulation. Good substituent tolerance and gram-scale reaction showed the potential in fine chemicals modification and pharmaceutical synthesis.

2.
J Org Chem ; 89(17): 12693-12700, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39186693

RESUMO

FeTiO3 has emerged as an interesting semiconductor photocatalyst in organic synthesis. We herein describe a visible-light-induced semiheterogeneous strategy for the synthesis of 3-(2-oxoethyl)indolin-2-ones with moderate to good yields and good functional group compatibility using recyclable FeTiO3 as a photocatalyst and NHPI as a redox catalyst.

3.
J Org Chem ; 89(15): 10654-10659, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39018181

RESUMO

With an inexpensive and commercially available WO3 semiconductor as the heterogeneous photocatalyst, a catalytic amount of NPh3 as the single-electron donor, and ambient air as the single-electron acceptor and oxygen source, the semiheterogeneous photocatalytic hydroxylation of alkyl and aryl boronic acids was developed. A broad range of hydroxylated compounds can be obtained in excellent yields.

4.
J Org Chem ; 89(13): 9543-9550, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38874168

RESUMO

A visible-light-initiated C-H trifluoromethylation of quinoxalin-2(1H)-ones was established using a Z-scheme V2O5/g-C3N4 heterojunction as a recyclable photocatalyst in an inert atmosphere at room temperature under additive-free and mild conditions. A variety of trifluoromethylated quinoxalin-2-(1H)-one derivatives were heterogeneously generated in moderate to high yields, exhibiting good functional group tolerance. Remarkably, the recyclable V2O5/g-C3N4 catalyst could be reused five times with a slight loss of catalytic activity.

6.
Chemistry ; 30(41): e202304234, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-38644695

RESUMO

With both TEMPO and O2 (in air) as the homogeneous redox mediators, BiBrO as the heterogeneous semiconductor photocatalyst, the first example of semi-heterogeneous photocatalytic decarboxylative phosphorylation of N-arylglycines with diarylphosphine oxides was established. A series of α-amino phosphinoxides were efficiently synthesized.

7.
J Org Chem ; 89(9): 6117-6125, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38654588

RESUMO

The first paired electrolysis-enabled arylation of quinoxalin-2(1H)-ones was achieved using cyanoarenes as the arylation reagents. A variety of 3-arylquinoxalin-2(1H)-ones with various important functional groups were obtained in moderate to good yields under metal- and chemical oxidant-free conditions. With a pair of reductive and oxidative processes occurring among the substrates and reaction intermediates, the power consumption can be dramatically reduced.

8.
J Org Chem ; 89(6): 4113-4119, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38448366

RESUMO

The first example of an electrochemical multicomponent synthesis of selenium-containing compounds with inexpensive and abundant elemental selenium as the selenating reagent was developed. A variety of selenazol-2-amines were constructed in high yields with good functional group tolerance under metal-free and chemical oxidant-free conditions.

9.
Chem Commun (Camb) ; 59(94): 14029-14032, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37964611

RESUMO

With both ferrocene and air as the redox catalysts, for the first time, the low-cost natural ilmenite (FeTiO3) was successfully used for photocatalytic bond formations. Under the assistance of a traceless H-bond, and HCHO as the methylene reagent, a variety of imidazo[1,5-a]quinoxalinones were semi-heterogeneously photosynthesized in high yields with good functional group compatibility.

10.
J Org Chem ; 88(24): 16790-16796, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38016176

RESUMO

A general and efficient method for the synthesis of various selanyl phenanthrenes/polycyclic heteroaromatics through the electrophilic annulation of 2-alkynyl biaryls with diorganyl diselenides under metal-free and mild conditions was established. The sulfanyl phenanthrene was also obtained in moderate yields.

11.
ChemSusChem ; 16(19): e202300523, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37728196

RESUMO

A green and practical method for the electrochemical synthesis of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones through the three-component reaction of quinoxalin-2(1H)-ones, N-arylglycines and paraformaldehyde was reported. In this strategy, EtOH played dual roles (eco-friendly solvent and waste-free pre-catalyst) and the in situ generated ethoxide promoted triple sequential deprotonations.

12.
J Org Chem ; 88(13): 8360-8368, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37262353

RESUMO

A 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4-CzIPN)-photocatalyzed cascade arylation/cyclization reaction of 2-isocyanobiaryls and iodonium ylides was established for the synthesis of 6-arylated phenanthridines. This is the first example of employing iodonium ylides as aryl radical sources in a visible-light-induced radical cascade cyclization reaction.


Assuntos
Luz , Fenantridinas , Ciclização
14.
J Org Chem ; 88(4): 2288-2295, 2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36738288

RESUMO

A simple and practical electron donor-acceptor (EDA) strategy to synthesize various 3-alkylated coumarins from easily available coumarins and naturally abundant carboxylic acids under photocatalyst-, oxidant-, and additive-free and mild conditions is reported. Using Na2S as the catalytic electron donor, a series of primary, secondary, and tertiary carbon radicals can be efficiently generated, and the EDA complex can be regenerated without an alkaline additive.

15.
Molecules ; 28(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36771059

RESUMO

The first example of paired electrolysis-enabled cyanation of diaryl diselenides, with KSCN as the green cyanating agent, has been developed. A broad range of aryl selenocyanates can be efficiently synthesized under chemical-oxidant- and additive-free, energy-saving and mild conditions.

16.
Graefes Arch Clin Exp Ophthalmol ; 261(1): 223-231, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36029306

RESUMO

BACKGROUND: SFTs are thought to have an unpredictable clinical course and currently have no recognized prognostic criterion. Our study aimed to determine the relationship between clinicopathological characteristics and the prognosis of patients with orbital SFTs. METHODS: The clinicopathological features of these patients were extracted from clinical records. The relationships between these features and prognosis were analysed. RESULTS: The positive rates of CD34, CD99, Blc2, and STAT6 expression were 90.3%, 90.3%, 83.9%, and 100%, respectively. The tumour recurrence rate was 38.7%. A higher recurrence rate was observed in patients with Ki67 index ≥ 5 (56.25% vs. 20%, P = 0.038). CONCLUSION: A Ki67 index ≥ 5 was an effective parameter for predicting tumour recurrence of orbital SFTs. Close follow-up is needed for these patients.


Assuntos
Hemangiopericitoma , Febre Grave com Síndrome de Trombocitopenia , Tumores Fibrosos Solitários , Humanos , Antígeno Ki-67 , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/patologia , Tumores Fibrosos Solitários/diagnóstico , Tumores Fibrosos Solitários/cirurgia , Tumores Fibrosos Solitários/metabolismo , Hemangiopericitoma/patologia , Biomarcadores Tumorais
17.
Org Biomol Chem ; 21(2): 370-374, 2023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36515252

RESUMO

A concise and efficient ring-opening difluorination strategy was developed for the synthesis of highly functionalized hydroxy-containing α,α-difluoro-ß-ketoamides from the one-pot multicomponent reaction of 4-aminocoumarins, NFSI, and water in dimethyl carbonate (DMC) as a green solvent. The reactions were smoothly achieved under visible light irradiation in air at room temperature without the addition of any other external photocatalysts. With this protocol, various α,α-difluoro-ß-ketoamides were successfully synthesized under mild conditions (25 examples, 73-91% yields). This transition-metal-free synthetic procedure shows good functional group compatibility and attractive practical potential for large-scale synthesis.


Assuntos
Amidas , Luz , Solventes
18.
Org Biomol Chem ; 20(43): 8501-8505, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36268850

RESUMO

The first example of the electrocatalytic multicomponent synthesis of 4-chloro/bromo/iodopyrazoles from hydrazines, acetylacetones and sodium halides under chemical oxidant- and external electrolyte-free conditions has been developed. Sodium halides played a dual role as a halogenation reagent and a supporting electrolyte. Mechanism studies revealed that the bromination reaction proceeded via an ionic pathway, whereas both chlorination and iodination proceeded via a radical pathway.


Assuntos
Halogênios , Sódio , Halogenação , Oxidantes , Íons
19.
Chem Asian J ; 17(1): e202101139, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-34837338

RESUMO

With eco-friendly and sustainable CO2 -derived dimethyl carbonate as the sole solvent, the visible-light-induced cascade radical reactions have been established as a green and efficient tool for constructing various CHF2 /CClF2 /CBrF2 -substituted ring-fused quinazolinones.

20.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(3): 510-515, 2021 May.
Artigo em Chinês | MEDLINE | ID: mdl-34018373

RESUMO

OBJECTIVE: To explore the clinical features of thyroid-associated ophthalmopathy (TAO) with extraocular muscle involvement. METHODS: The data of 2170 TAO patients who were seen at the Orbital Disease Clinic, West China Hospital, Sichuan University from September, 2009 to January, 2020 were collected retrospectively. The extraocular muscle involvement of these patients was confirmed by CT or MRI. Their general condition, medical history, clinical manifestations and imaging features were analyzed retrospectively. RESULTS: Among the 2170 TAO patients, 932 were male and 1238 were female. The mean (± SD) age of all the patients was (46.95±13.06) years, ranging between 6 and 85. 1684 patients (77.60%) suffered from hyperthyroidism, 13 patients (0.59%) had thyroid cancer, 80 patients (3.69%) had hypothyroidism, and 393 patients (18.11%) had normal thyroid function. Proptosis (55.25%) and diplopia (33.09%) were the main reasons for their visits to the clinic, and restricted eye movements (83.46%) was the most common sign. 122 patients with a mean age of (53.24±13.07) years did not show any eyelid sign and had only extraocular muscle involvement. The 2170 TAO patients had a total of 3799 eyes of extrocular muscle involvement, with 541 patients experiencing monocular involvement and 1629 patients, binocular involvement; 1204 eyes (31.69%) had a single extrocular muscle involved and 2595 eyes (68.31%) had multiple extrocular muscles involved. Inferior rectus was the most commonly involved muscle, followed by superior rectus, medial rectus, and lateral rectus in descending order of involvement frequency. Of the 1014 patients who underwent enhanced MRI, 71.99% were shown to be in the active phase. 69.03% of the 775 patients identified as being in inactive phase according to their clinical activity score (CAS) were shown to be in the active phase according to their MRI results. CONCLUSION: TAO patients with extraocular muscle involvement have their own specific clinical manifestations. CT and MRI can both be used to assist in the diagnosis of extraocular muscle involvement. MRI can be used to assess the pathological stage of extraocular muscles and is more sensitive than CAS.


Assuntos
Oftalmopatia de Graves , Adulto , Idoso , China , Feminino , Oftalmopatia de Graves/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculos Oculomotores/diagnóstico por imagem , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA