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A facile and efficient catalyst-/metal-/oxidant-free DBU-promoted deaminative thiolation reaction of 1H-benzo[d]imidazol-2-amines and benzo[d]oxazol-2-amines has been developed at room temperature conditions in a one-pot protocol. This practical three-component strategy represents a novel and environmentally friendly reaction pathway toward the straightforward synthesis of various 2-thio-1H-benzo[d]imidazoles and 2-thiobenzo[d]oxazoles using carbon disulfide as a sulfur source through C-N bond cleavage and C-S bond formation process. Different types of 1H-benzo[d]imidazol-2-amines, benzo[d]oxazol-2-amines, and organic bromides are suitable substrates. The gram-scale and late-stage modification experiments provide the potential applications based on this methodology in the field of organic and medicinal chemistry.
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An efficient copper-catalyzed aerobic oxidative cross-dehydrogenative coupling reaction for the synthesis of multisubstituted phosphorylhydrazides from N,N-disubstituted hydrazines and hydrogen phosphoryl compounds is accomplished. The reaction proceeds under mild conditions without the addition of any external oxidants and bases. This work reported here represents a direct P(âO)-N-N bond formation with the advantages of being operationally simple, good functional group tolerance, and high atom and step economy. Furthermore, the selected compounds exhibit potential inhibitory activity against tumor cells, which can be used in the field of screening of anticancer agents as new chemical entities.
Assuntos
Antineoplásicos , Hidrazinas , Antineoplásicos/farmacologia , Catálise , Cobre/química , Hidrazinas/química , Hidrazinas/farmacologia , FosforilaçãoRESUMO
A metal- and oxidant-free three-component desulfurization and deamination condensation of amidines, isothiocyanates, and hydrazines for the synthesis of structurally diverse fully substituted 1H-1,2,4-triazol-3-amines is described. The reaction proceeds without the requirement of any external catalysts, metals, ligands, or oxidants. This [2 + 1 + 2] cyclization strategy involves C-N and C-S bond cleavage and the formation of new C-N bonds in one pot. This transformation provides a series of full substituted 1H-1,2,4-triazol-3-amines with advantages of a broad substrates scope, mild reaction conditions, environmental friendliness, and easy gram-scale applications. The fluorescence and aggregation-induced emission (AIE) properties of selected products were further tested. These synthesized 1H-1,2,4-triazol-3-amines may be worth investigating for further applications in the fields of organic chemistry, medicinal chemistry, and optical materials.
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A new photocatalyst-free visible-light-enhanced strategy for the synthesis of pyrazolo[1,5-a][1,3,5]triazine-2,4-diamines via the formation of electron donor-acceptor (EDA) complexes is reported. The in situ generated pyrazolthiourea intermediates from 1H-pyrazol-3-amines and isothiocyanates undergo formal [4 + 2] annulation with 1,1,3,3-tetramethylguanidines (TMG) to deliver the corresponding products involved in three C-N bond formations in a one-pot protocol. The formation of EDA complex from pyrazolthiourea and TMG is confirmed by UV-vis spectroscopy and 1H NMR experiments. Moreover, this mild reaction proceeds in the absence of any external transition metals, oxidants, bases, and ligands. This efficient methodology for the synthesis of purine analogues pyrazolo[1,5-a][1,3,5]triazine-2,4-diamines provides potential synthetic applications in the field of drug research and development.
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Diaminas , Triazinas , Aminas , Luz , PurinasRESUMO
BACKGROUND AND AIMS: Numerous studies have shown that people who have Internet addiction (IA) are more likely to experience poor sleep quality than people who do not. However, few studies have explored mechanisms underlying the relation between IA and poor sleep quality. As a first attempt to address this knowledge gap, a cross-sectional design was applied, and structural equation modeling was used to explore the direct relationship between IA and poor sleep quality, as well as the potential mediating roles of rumination and bedtime procrastination. METHODS: A convenience sample, consisting of 1,104 Chinese University students (696 females or 63%), completed an online survey that included the following measures: Young's 8-item Internet Addiction Diagnosis Questionnaire, the Pittsburgh Sleep Quality Index, the Ruminative Responses Scale, and the Bedtime Procrastination Scale. RESULTS: While the direct path between IA and poor sleep quality was not found to be significant, rumination and bedtime procrastination were each shown to separately mediate the predictive effect of IA on poor sleep quality. However, the greatest level of support was found for the sequential mediating effects of rumination and bedtime procrastination between IA and poor sleep quality. CONCLUSION: While rumination and bedtime procrastination were both shown to be important independent mediators for the relation between IA and poor sleep quality, their combined effect was as great as either alone.
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Procrastinação , Distúrbios do Início e da Manutenção do Sono , Estudos Transversais , Feminino , Humanos , Internet , Transtorno de Adição à Internet , SonoRESUMO
The photodriven direct C-C/C-N bond formation initiated by electron donor-acceptor (EDA) complexes for the synthesis of indoles has been accomplished via [3+2] annulations of secondary arylamines with alkynes using IC4F9 as oxidants in the absence of any photocatalysts and metals. This green transformation exhibits the advantages of operational simplicity, good functional tolerances, and mild reaction conditions. The in situ generated EDA complexes derived from arylamines with alkynes were characterized by UV-vis absorption spectrometry and NMR titration experiments.