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1.
Front Public Health ; 12: 1392696, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39011334

RESUMEN

Objective: To investigate the short-term changes in chest CT images of low-altitude populations after entering a high-altitude environment. Methods: Chest CT images of 3,587 people from low-altitude areas were obtained within one month of entering a high-altitude environment. Abnormal CT features and clinical symptoms were analyzed. Results: Besides acute high-altitude pulmonary edema, the incidence of soft tissue space pneumatosis was significantly higher than that in low-altitude areas. Pneumatosis was observed in the mediastinum, cervical muscle space, abdominal cavity, and spinal cord epidural space, especially the mediastinum. Conclusion: In addition to acute high-altitude pulmonary edema, spontaneous mediastinal emphysema often occurs when individuals in low-altitude areas adapt to the high-altitude environment of cold, low-pressure, and hypoxia. When the gas escapes to the abdominal cavity, it is easy to be misdiagnosed as gastrointestinal perforation. It is also not uncommon for gas accumulation to escape into the epidural space of the spinal cord. The phenomenon of gas diffusion into distant tissue space and the mechanism of gas escape needs to be further studied.


Asunto(s)
Mal de Altura , Altitud , Tomografía Computarizada por Rayos X , Humanos , Masculino , Femenino , Persona de Mediana Edad , Adulto , Mal de Altura/diagnóstico por imagen , Anciano , Enfisema Mediastínico/diagnóstico por imagen , Enfisema Mediastínico/etiología , Hipertensión Pulmonar/diagnóstico por imagen , China
2.
Front Microbiol ; 15: 1422637, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39027113

RESUMEN

Airborne microorganisms, an emerging global health threat, have attracted extensive studies. However, few attentions have been paid to the seasonal distribution of airborne pathogens, in particular their associations with antibiotic resistance genes (ARGs). To this end, two-week daily PM2.5 samples were consecutively collected from Nanchang in four seasons, and the human-to-human pathogens were screened based on high-throughput sequencing. The results showed that there were 20 pathogenic taxa in PM2.5 in Nanchang, and the highest relative abundance of pathogens was observed in winter (5.84%), followed by summer (3.51%), autumn (2.66%), and spring (1.80%). Although more than half of pathogenic taxa were shared by the four seasons, the analysis of similarities showed that pathogenic community was shaped by season (r = 0.16, p < 0.01). Co-occurrence network analysis disclosed significant interactions among pathogens in each season. Moreover, some dominant pathogens such as Plesiomonas shigelloides, Bacteroides fragilis, and Escherichia-Shigella were hub pathogens. In addition, PICRUSt2 predicted that there were 35 high-risk ARG subtypes in PM2.5, and the pathogens had strongly positive correlations with these ARGs. Even some pathogens like Plesiomonas shigelloides, Bacteroides fragilis, Aeromonas, Citrobacter, may be multi-drug resistant pathogens, including beta-lactam, aminoglycosides, chloramphenicol and multi-drug resistances, etc. Both air pollutants and meteorological conditions contributed to the seasonal variation of airborne pathogenic bacteria (r = 0.15, p < 0.01), especially CO, O3, PM2.5, temperature and relative humidity. This study furthers our understanding of airborne pathogens and highlights their associations with ARGs.

3.
Quant Imaging Med Surg ; 14(5): 3731-3743, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38720861

RESUMEN

Background: Post-hepatectomy liver failure (PHLF) is still a predominant cause of hepatectomy-related mortality. However, it is difficult to evaluate the remnant liver functional reserve accurately before surgery to prevent PHLF. In this study, we aimed to explore the role of gadoxetate disodium-enhanced magnetic resonance imaging (MRI) in evaluating remnant liver functional reserve. Methods: For this cross-sectional study, the sample retrospectively included 56 patients undergoing liver resections of at least three segments between June 2019 and September 2022 at The General Hospital of the Western Theater Command. Pre-surgery assessments involved liver computer tomography (CT), an indocyanine green (ICG) clearance test, the Child-Pugh scoring system, and liver function serum biochemical indicators. Each patient underwent a gadoxetate disodium-enhanced MRI before the hepatectomy, and we measured the remnant hepatocellular uptake index (rHUI) as well as the standard remnant hepatocellular uptake index (SrHUI). We examined the diagnostic utility of rHUI, SrHUI, indocyanine green retention rate of 15 minutes (ICG R15), and Albumin for PHLF. Receiver operating characteristics (ROC) analyses were used to measure the preoperative liver function parameters (namely, rHUI, SrHUI, ICG R15, and Albumin) for predicting PHLF. The areas under the curve (AUCs) were calculated and compared between different preoperative liver function parameters using the Wilson/Brown method. The Pearson or Spearman correlation coefficient was used for correlation analysis between ICG R15, Albumin, and rHUI and between ICG R15, Albumin, and SrHUI, respectively. Results: Twelve patients (21.43%) had complications of PHLF. We found significant differences in rHUI, SrHUI, ICG R15, and Albumin between the non-PHLF and PHLF groups. The pooled r between ICG R15 and rHUI was -0.591 [95% confidence interval (CI): -0.740 to -0.389, P<0.001], and between ICG R15 and SrHUI was -0.534 (95% CI: -0.703 to -0.308, P<0.001). The area under the curve (AUC) values of rHUI, SrHUI, ICG R15, and Ablumin were 0.871 (sensitivity 81.82%; specificity 91.67%), 0.878 (sensitivity 79.55%; specificity 83.33%), 0.835 (sensitivity 99.73%; specificity 66.67%), and 0.782 (sensitivity 88.64%; specificity 58.33%), respectively. Conclusions: We found that the rHUI and SrHUI calculated using the gadoxetate disodium-enhanced MRI reflected a combination of remnant hepatocyte function and liver volume, and these were useful as a quantitative assessment indicator of remnant liver functional reserve and can be a better predictor of PHLF after major hepatic resection.

4.
Arch Esp Urol ; 77(2): 217-223, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38583015

RESUMEN

OBJECTIVE: We aimed to investigate the value of magnetic resonance imaging (MRI) radiomics combined with serum prostate-specific antigen (PSA) in predicting the extracapsular extension (ECE) of prostate cancer. METHODS: In total, 213 patients with prostate cancer admitted to our hospital from May 2021 to April 2023 were retrospectively enrolled as observation subjects. Based on the presence or absence of extracapsular extension, the patients were divided into occurrence (n = 70) and non-occurrence (n = 143) groups. The clinical data, PSA levels, Prostate Imaging Reporting and Data System (PI-RADS®), and MRI-ECE scores of the two groups were compared. RESULTS: In total, 80 patients were included in the occurrence (n = 40) and non-occurrence groups (n = 40), and no statistical significance was observed in the baseline data of the two groups. Preoperative PSA levels were significantly higher in the occurrence group than in the non-occurrence group, and the PI-RADS and MRI-ECE scores of each group differed significantly (p < 0.05). The area under the curve (AUC) for the combined determination of PSA levels and PI-RADS and MRI-ECE scores was 0.900, which was significantly higher than the AUC for the individual determination of the mentioned indicators (p < 0.05). CONCLUSIONS: The combination of MRI radiomics and PSA can accurately predict the extracapsular extension of prostate cancer; Thus, it is a favorable reference for subsequent precise diagnosis and treatment.


Asunto(s)
Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/cirugía , Imagen por Resonancia Magnética/métodos , Antígeno Prostático Específico , Estudios Retrospectivos , Radiómica , Extensión Extranodal
5.
Sci Bull (Beijing) ; 69(12): 1866-1874, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38670850

RESUMEN

The merging of transition metal catalysis with electrochemistry has become a powerful tool for organic synthesis because catalysts can govern the reactivity and selectivity. However, coupling catalysts with alkyl radical species generated by anodic oxidation remains challenging because of electrode passivation, dimerization, and overoxidation. In this study, we developed convergent paired electrolysis for the coupling of nickel catalysts with alkyl radicals derived from photoinduced ligand-to-metal charge-transfer of cyclic alcohols and iron catalysts, providing a practical method for site-specific and remote arylation of ketones. The synergistic use of photocatalysis with convergent paired electrolysis can provide alternative avenues for metal-catalyzed radical coupling reactions.

6.
Arch. esp. urol. (Ed. impr.) ; 77(2): 217-223, mar. 2024. tab
Artículo en Inglés | IBECS | ID: ibc-231944

RESUMEN

Objective: We aimed to investigate the value of magnetic resonance imaging (MRI) radiomics combined with serum prostate-specific antigen (PSA) in predicting the extracapsular extension (ECE) of prostate cancer. Methods: In total, 213 patients with prostate cancer admitted to our hospital from May 2021 to April 2023 were retrospectively enrolled as observation subjects. Based on the presence or absence of extracapsular extension, the patients were divided into occurrence (n = 70) and non-occurrence (n = 143) groups. The clinical data, PSA levels, Prostate Imaging Reporting and Data System (PI-RADS®), and MRI-ECE scores of the two groups were compared. Results: In total, 80 patients were included in the occurrence (n = 40) and non-occurrence groups (n = 40), and no statistical significance was observed in the baseline data of the two groups. Preoperative PSA levels were significantly higher in the occurrence group than in the non-occurrence group, and the PI-RADS and MRI-ECE scores of each group differed significantly (p < 0.05). The area under the curve (AUC) for the combined determination of PSA levels and PI-RADS and MRI-ECE scores was 0.900, which was significantly higher than the AUC for the individual determination of the mentioned indicators (p < 0.05). Conclusions: The combination of MRI radiomics and PSA can accurately predict the extracapsular extension of prostate cancer; Thus, it is a favorable reference for subsequent precise diagnosis and treatment. (AU)


Asunto(s)
Humanos , Neoplasias de la Próstata , Antígeno Prostático Específico , Espectroscopía de Resonancia Magnética , Predicción , Estudios Retrospectivos
7.
Sci Total Environ ; 925: 171584, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38492598

RESUMEN

The global concern regarding the health risk associated with airborne microorganisms has prompted research in this field. However, there is a lack of systematic investigation into the particle-size distribution of airborne bacterial and fungal communities associated with seasons, which determines where they are deposited in the human respiratory tract. To address this gap, we conducted a study in Nanchang, located in central China, where we collected both coarse and fine particles during summer and winter seasons. The results demonstrated that microbial community exhibited obvious seasonal and particle-size variations except bacterial community in fine particles. Certain taxa (e.g., Bacteroidales, Ktedonobacterales, Capnodiales) displayed either seasonal and/or particle-size preferences. Furthermore, airborne microorganisms in coarse particles were more sensitive to season and particle size compared to those in fine particles, with fungal community being more susceptible than bacterial community. The susceptibility can be attributed to their high vulnerability to air pollutants and meteorological conditions, primarily PM2.5 and PM10. Additionally, a greater relative abundance of pathogenic fungi was observed in fine particles, even though microbial diversity in coarse particles was noticeably higher than that in fine particles. Furthermore, some predominant pathogens such as Alternaria, Nigrospora, and Escherichia-Shigella not only had particle size and/or seasonal preferences, but also were strongly correlated with environmental factors. This study advances our understanding of atmospheric pathogenic microorganisms and highlights the fungal health threat.


Asunto(s)
Contaminantes Atmosféricos , Micobioma , Humanos , Tamaño de la Partícula , Material Particulado/análisis , Estaciones del Año , Microbiología del Aire , Monitoreo del Ambiente/métodos , Contaminantes Atmosféricos/análisis , Bacterias , Alternaria
8.
Postgrad Med J ; 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38507237

RESUMEN

PURPOSE: To construct a clinical noncontrastive computed tomography (NCCT) deep learning joint model for predicting early hematoma expansion (HE) after cerebral hemorrhage (sICH) and evaluate its predictive performance. METHODS: All 254 patients with primary cerebral hemorrhage from January 2017 to December 2022 in the General Hospital of the Western Theater Command were included. According to the criteria of hematoma enlargement exceeding 33% or the volume exceeding 6 ml, the patients were divided into the HE group and the hematoma non-enlargement (NHE) group. Multiple models and the 10-fold cross-validation method were used to screen the most valuable features and model the probability of predicting HE. The area under the curve (AUC) was used to analyze the prediction efficiency of each model for HE. RESULTS: They were randomly divided into a training set of 204 cases in an 8:2 ratio and 50 cases of the test set. The clinical imaging deep feature joint model (22 features) predicted the area under the curve of HE as follows: clinical Navie Bayes model AUC 0.779, traditional radiology logistic regression (LR) model AUC 0.818, deep learning LR model AUC 0.873, and clinical NCCT deep learning multilayer perceptron model AUC 0.921. CONCLUSION: The combined clinical imaging deep learning model has a high predictive effect for early HE in sICH patients, which is helpful for clinical individualized assessment of the risk of early HE in sICH patients.

10.
Science ; 382(6669): 458-464, 2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37883537

RESUMEN

Stereochemical enrichment of a racemic mixture by deracemization must overcome unfavorable entropic effects as well as the principle of microscopic reversibility; recently, photochemical reaction pathways unveiled by the energetic input of light have led to innovations toward this end, most often by ablation of a stereogenic C(sp3)-H bond. We report a photochemically driven deracemization protocol in which a single chiral catalyst effects two mechanistically different steps, C-C bond cleavage and C-C bond formation, to achieve multiplicative enhancement of stereoinduction, which leads to high levels of stereoselectivity. Ligand-to-metal charge transfer excitation of a titanium catalyst coordinated by a chiral phosphoric acid or bisoxazoline efficiently enriches racemic alcohols that feature adjacent and fully substituted stereogenic centers to enantiomeric ratios up to 99:1. Mechanistic investigations support a pathway of sequential radical-mediated bond scission and bond formation through a common prochiral intermediate and reveal that, although the overall stereoenrichment is high, the selectivity in each individual step is moderate.

12.
Chem Sci ; 14(25): 6841-6859, 2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37389263

RESUMEN

The selective functionalization of alkanes has long been recognized as a prominent challenge and an arduous task in organic synthesis. Hydrogen atom transfer (HAT) processes enable the direct generation of reactive alkyl radicals from feedstock alkanes and have been successfully employed in industrial applications such as the methane chlorination process, etc. Nevertheless, challenges in the regulation of radical generation and reaction pathways have created substantial obstacles in the development of diversified alkane functionalizations. In recent years, the application of photoredox catalysis has provided exciting opportunities for alkane C-H functionalization under extremely mild conditions to trigger HAT processes and achieve radical-mediated functionalizations in a more selective manner. Considerable efforts have been devoted to building more efficient and cost-effective photocatalytic systems for sustainable transformations. In this perspective, we highlight the recent development of photocatalytic systems and provide our views on current challenges and future opportunities in this field.

13.
Nucl Med Commun ; 44(8): 703-708, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37184491

RESUMEN

BACKGROUND: Airway stenosis secondary to non-small cell lung cancer (NSCLC) is one of the severe complications that can lead to life-threatening outcomes. OBJECTIVE: To investigate the clinical utility of computed tomography (CT)-guided interstitial implantation of radioactive I-125 seeds in the treatment of hilar airway stenosis caused by NSCLC. METHODS: The cases of hilar airway stenosis caused by NSCLC in our hospital from 2017 to 2022 were collected and divided into observation and control groups. Both groups underwent conventional lung cancer treatment, and the observation group was treated with CT-guided interstitial implantation of radioactive I-125 seeds. The mean tumor diameter, hilar airway stenosis, and obstructive pneumonia scores at 3 months after treatment were compared between the two groups. RESULTS: After 3 months of treatment, the mean tumor diameter (28.8 ±â€…9.3 mm vs 49.33 ±â€…16.75 mm, P  < 0.001), hilar airway stenosis (20.55 ±â€…30.36% vs 84.85 ±â€…26.19%, P  < 0.001), and obstructive pneumonia score (2.19 ±â€…1.41 vs 3.48 ±â€…1.12, P  < 0.001) of the observation group were significantly lower than those of the control group. CONCLUSION: CT-guided interstitial implantation of I (125) radioactive seeds in the treatment of hilar airway stenosis caused by NSCLC can effectively reduce the tumor volume, relieve airway stenosis, and alleviate the associated obstructive pneumonia and has a certain value of application in the clinic.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/radioterapia , Radioisótopos de Yodo/uso terapéutico , Constricción Patológica/tratamiento farmacológico , Tomografía Computarizada por Rayos X
14.
Chem Commun (Camb) ; 59(27): 4055-4058, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36929170

RESUMEN

A synergistic photocatalytic system using a bisphosphonium catalyst and a cobalt catalyst has been developed, enabling the selective oxidation of benzylic alcohols under oxidant-free and environmentally benign conditions. High efficiencies have been obtained for a variety of alcohol substrates, and exclusive selectivity for aldehyde products has been achieved across the board. Furthermore, this photocatalytic system proved to be efficient when performed under continuous-flow conditions, even using a simple and easily assembled continuous-flow setup.

15.
World J Clin Cases ; 11(1): 225-232, 2023 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-36687183

RESUMEN

BACKGROUND: High flow priapism (HFP) is a rare type of priapism. Perineal trauma is the most common cause of HFP. Trauma-induced penile artery injury may lead to an arterial-cavernosal fistula, whereas persistent irregular arterial blood flow entering the corpora cavernosum can cause a persistent penile erection. The routine treatment of HFP focuses on addressing the abnormal penile erectile status and avoiding post-treatment erectile dysfunction. Interventional embolization is an important therapeutic modality for HFP, and bilateral embolization therapy is currently the most commonly used technique for patients with bilateral cavernous artery fistulas; however, unilateral embolization therapy has yet to be reported. CASE SUMMARY: Herein, we report of the case of a 26-year-old Chinese male who presented with a persistent abnormal erection for 12 h after perineal impact injury. Medical history, cavernous arterial blood gas analysis and radiological examinations led to a diagnosis of HFP caused by bilateral cavernous artery fistulas. We performed routine conservative treatment (compression therapy and ice application) for the patient after admission; however, 10 d later, his symptoms had not been relieved. After completion of the preoperative workup, right (severe side) selective perineal artery embolization was performed; the left cavernous artery fistula was left untreated. After postoperative continuation of conservative treatment for 72 h, the patient experienced complete penile thinning. The patient had no symptoms of erectile dysfunction over a follow-up period of 12 mo. CONCLUSION: Compared with bilateral cavernous artery fistula embolization, we believe that unilateral cavernous artery fistula embolization can achieve positive clinical efficacy and reduce the risk of postoperative erectile dysfunction secondary to penile ischemia.

16.
Neurol Sci ; 44(5): 1709-1717, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36622475

RESUMEN

BACKGROUND: Acute cerebrovascular accidents, long-term hypoperfusion, and/or remote neuronal degeneration may lead to structural alterations in patients with moyamoya disease (MMD). This study sought to comprehensively investigate the distribution characteristics of subcortical gray matter volume and their correlations with angiographic changes in the intracranial artery in patients with MMD. METHOD: One hundred forty-two patients with MMD and 142 age- and sex-matched healthy controls underwent 3-dimensional high-resolution structural magnetic resonance imaging. Volumes of subcortical gray matter and subregions of the hippocampus and amygdala were calculated, and the degree of stenosis/occlusion of intracranial arteries in patients with MMD was evaluated on MR angiography. RESULTS: Volume reductions in the thalamus, caudate, putamen, hippocampus, amygdala, pallidum, and nucleus accumbens were found in patients with MMD. Hippocampal subfields and amygdala subnuclei in patients with MMD showed distinct vulnerability, and morphological alterations in specific subregions were more obvious than in the whole hippocampus/amygdala. Volume loss in several subcortical areas was related to disease duration and intracranial arterial changes. CONCLUSIONS: Our findings revealed structural alteration patterns of subcortical gray matter in MMD. The specific atrophy in subregions of the hippocampus and the amygdala suggested potential cognitive and affective impairments in MMD, which warrants further investigation. Chronic cerebral hemodynamic alterations in MMD may play a pivotal role in morphological changes in subcortical areas.


Asunto(s)
Sustancia Gris , Enfermedad de Moyamoya , Humanos , Adulto , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/patología , Enfermedad de Moyamoya/diagnóstico por imagen , Núcleo Accumbens , Imagen por Resonancia Magnética/métodos , Atrofia/patología , Encéfalo/patología
17.
J Am Chem Soc ; 145(1): 359-376, 2023 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-36538367

RESUMEN

The intermediacy of alkoxy radicals in cerium-catalyzed C-H functionalization via H-atom abstraction has been unambiguously confirmed. Catalytically relevant Ce(IV)-alkoxide complexes have been synthesized and characterized by X-ray diffraction. Operando electron paramagnetic resonance and transient absorption spectroscopy experiments on isolated pentachloro Ce(IV) alkoxides identified alkoxy radicals as the sole heteroatom-centered radical species generated via ligand-to-metal charge transfer (LMCT) excitation. Alkoxy-radical-mediated hydrogen atom transfer (HAT) has been verified via kinetic analysis, density functional theory (DFT) calculations, and reactions under strictly chloride-free conditions. These experimental findings unambiguously establish the critical role of alkoxy radicals in Ce-LMCT catalysis and definitively preclude the involvement of chlorine radical. This study has also reinforced the necessity of a high relative ratio of alcohol vs Ce for the selective alkoxy-radical-mediated HAT, as seemingly trivial changes in the relative ratio of alcohol vs Ce can lead to drastically different mechanistic pathways. Importantly, the previously proposed chlorine radical-alcohol complex, postulated to explain alkoxy-radical-enabled selectivities in this system, has been examined under scrutiny and ruled out by regioselectivity studies, transient absorption experiments, and high-level calculations. Moreover, the peculiar selectivity of alkoxy radical generation in the LMCT homolysis of Ce(IV) heteroleptic complexes has been analyzed and back-electron transfer (BET) may have regulated the efficiency and selectivity for the formation of ligand-centered radicals.


Asunto(s)
Cloro , Hidrógeno , Hidrógeno/química , Cinética , Ligandos , Metales , Etanol , Catálisis
18.
Chem Rev ; 122(2): 2429-2486, 2022 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-34613698

RESUMEN

Alkoxy radicals are highly reactive species that have long been recognized as versatile intermediates in organic synthesis. However, their development has long been impeded due to a lack of convenient methods for their generation. Thanks to advances in photoredox catalysis, enabling facile access to alkoxy radicals from bench-stable precursors and free alcohols under mild conditions, research interest in this field has been renewed. This review comprehensively summarizes the recent progress in alkoxy radical-mediated transformations under visible light irradiation. Elementary steps for alkoxy radical generation from either radical precursors or free alcohols are central to reaction development; thus, each section is categorized and discussed accordingly. Throughout this review, we have focused on the different mechanisms of alkoxy radical generation as well as their impact on synthetic utilizations. Notably, the catalytic generation of alkoxy radicals from abundant alcohols is still in the early stage, providing intriguing opportunities to exploit alkoxy radicals for diverse synthetic paradigms.


Asunto(s)
Alcoholes , Luz , Catálisis , Oxidación-Reducción
19.
J Am Chem Soc ; 143(13): 4896-4902, 2021 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-33756079

RESUMEN

Under mild reaction conditions with inexpensive cerium and nickel catalysts, easily accessible free alcohols can now be utilized as operationally simple and robust carbon pronucleophiles in selective C(sp3)-C(sp2) cross-couplings. Facilitated by automated high-throughput experimentation, sterically encumbered benzoate ligands have been identified for robust cerium complexes, enabling the synergistic cooperation of cerium catalysis in the emerging metallaphotoredox catalysis. A broad range of free alcohols and aromatic halides can be facilely employed in this transformation, representing a new paradigm for the C(sp3)-C(sp2) bond construction between free alcohols and aryl halides with the extrusion of formaldehyde. Moreover, mechanistic investigations have been conducted, leading to the identification of a tribenzoate cerium(III) complex as a viable intermediate.

20.
Angew Chem Int Ed Engl ; 60(10): 5370-5376, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33259085

RESUMEN

We describe a cerium-catalyzed aerobic oxidative ring expansion for the expedient construction of synthetically challenging macrolactones under visible-light conditions. Cyanoanthracene has been employed as co-catalyst to accelerate the turnover of the cerium cycle leading to a fast conversion within 20 min of irradiation. Taking advantage of the high efficiency and operationally simple conditions, a collection of over 100 macrolactones equipped with ring systems ranging from 9- to 19-membered macrocycles have been prepared from simple building blocks. Moreover, the enabling potential of this strategy to simplify the generation of molecular complexity has been demonstrated through the concise synthesis of sonnerlactone.

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