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Due to the innate highly reactive properties and short life‐time, organic free radicals can often serve as promoters or intermediates to engage in various radical transformations, which are often otherwise difficult to access by ionic pathway‐based mechanisms. With the evolvement of radical chemistry, chiral radical catalyzed‐transformations have recently emerged as an attractive and robust platform for synthesis of chiral molecules of interest. Herein, we highlight several creative and strategic advances in chiral radical catalyst design, cyclization reaction achievements, and future challenges. Key Scientists: In the 1980s, some pioneering studies by Feldman and Oshima revealed that the thiyl radical could catalyze cyclization of vinylcyclopropane with alkenes, providing access to racemic cyclopentanes. In 1996, Brian P. Roberts reported an interesting enantioselective hydrosilylation of prochiral alkenes by using thioglucose‐derived chiral thiyl radical catalysts. Since then, chiral radical catalysis has become an emerging and promising catalytic strategy in organic synthesis. However, this field has not been extensively explored further until the Maruoka group in 2014 achieved the asymmetric C—C bond formation by employing a newly designed indanol core‐based chiral thiyl radical catalyst. In this protocol, an enantioselective radical cyclization of vinylcyclopropanes with electron‐rich alkenes was developed. In 2020, Chen and Xiao disclosed a nitrogen radical‐catalyzed version of this reaction. Later, this strategy was further expanded to metalloradical catalyzed asymmetric radical cascade cyclization reactions by Zhang in 2021. Later on, Wang, Fu and Zhang et al. described a novel class of boryl radical‐catalyzed asymmetric radical cycloisomerization reactions, further showcasing enormous synthetic potential of chiral radical catalysis. This Emerging Topic has focused on asymmetric radical cyclization reactions involving diverse chiral radical catalysts. [ABSTRACT FROM AUTHOR]

Organic azides are highly reactive, which have long established as versatile building blocks in the assembly of structurally diverse N‐containing heterocycles. The conversion of organic azides into high‐value compounds is of great importance and a subject of enormous current interest. Transition metal‐catalyzed C(sp2)−H amination/annulation of organic azides provides a powerful tool for the transformation of organic azides into a wide range of biologically important heterocyclic frameworks. In this review, we aim to summarize the recent progress on organic azides‐mediated C(sp2)−H amination/annulation for N‐heterocycle synthesis enabled by transition metal catalysts. Representative strategies are discussed in detail, including catalytic systems, reaction scopes, limitations and mechanisms. [ABSTRACT FROM AUTHOR]

Abstract: A visible light‐induced photocatalytic radical addition/cyclization reaction of o‐vinyl‐N‐alkoxybenzamides has been accomplished for efficient synthesis of diversely functionalized CF3‐containing iminoisobenzofurans. This external oxidant‐free and mild protocol features ready availability of starting materials, excellent regioselectivity, good substrate scope and functional group tolerance. [ABSTRACT FROM AUTHOR]

A visible-light-induced photocatalytic oxytrifluoromethylation reaction of N-allylamides has been developed for the efficient synthesis of CF3-containing oxazolines and benzoxazines under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Background: Acute pancreatitis (AP) is a disease caused by abnormal activation of pancreatic enzymes and can lead to self-digestion of pancreatic tissues and dysfunction of other organs. Enteral nutrition plays a vital role in the treatment of AP because it can meet the nutritional needs of patients, promote the recovery of intestinal function, and maintain the barrier and immune functions of the intestine. However, the risk of aspiration during enteral nutrition is high; once aspiration occurs, it may cause serious complications, such as aspiration pneumonia, and suffocation, posing a threat to the patient's life. This study aims to establish and validate a prediction model for enteral nutrition aspiration during hospitalization in patients with AP., Aim: To establish and validate a predictive model for enteral nutrition aspiration during hospitalization in patients with AP., Methods: A retrospective review was conducted on 200 patients with AP admitted to Chengdu Shangjin Nanfu Hospital, West China Hospital of Sichuan University from January 2020 to February 2024. Clinical data were collected from the electronic medical record system. Patients were randomly divided into a validation group ( n = 40) and a modeling group ( n = 160) in a 1:4 ratio, matched with 200 patients from the same time period. The modeling group was further categorized into an aspiration group ( n = 25) and a non-aspiration group ( n = 175) based on the occurrence of enteral nutrition aspiration during hospitalization. Univariate and multivariate logistic regression analyses were performed to identify factors influencing enteral nutrition aspiration in patients with AP during hospitalization. A prediction model for enteral nutrition aspiration during hospitalization was constructed, and calibration curves were used for validation. Receiver operating characteristic curve analysis was conducted to evaluate the predictive value of the model., Results: There was no statistically significant difference in general data between the validation and modeling groups ( P > 0.05). The comparison of age, gender, body mass index, smoking history, hypertension history, and diabetes history showed no statistically significant difference between the two groups ( P > 0.05). However, patient position, consciousness status, nutritional risk, Acute Physiology and Chronic Health Evaluation (APACHE-II) score, and length of nasogastric tube placement showed statistically significant differences ( P < 0.05) between the two groups. Multivariate logistic regression analysis showed that patient position, consciousness status, nutritional risk, APACHE-II score, and length of nasogastric tube placement were independent factors influencing enteral nutrition aspiration in patients with AP during hospitalization ( P < 0.05). These factors were incorporated into the prediction model, which showed good consistency between the predicted and actual risks, as indicated by calibration curves with slopes close to 1 in the training and validation sets. Receiver operating characteristic analysis revealed an area under the curve (AUC) of 0.926 (95%CI: 0.8889-0.9675) in the training set. The optimal cutoff value is 0.73, with a sensitivity of 88.4 and specificity of 85.2. In the validation set, the AUC of the model for predicting enteral nutrition aspiration in patients with AP patients during hospitalization was 0.902, with a standard error of 0.040 (95%CI: 0.8284-0.9858), and the best cutoff value was 0.73, with a sensitivity of 91.9 and specificity of 81.8., Conclusion: A prediction model for enteral nutrition aspiration during hospitalization in patients with AP was established and demonstrated high predictive value. Further clinical application of the model is warranted., Competing Interests: Conflict-of-interest statement: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Alkene bifunctionalizations are powerful tools for the rapid construction of structurally complex and valuable scaffolds, and such reactions typically involve the use of transition-metal catalysts or organocatalysts. Here, we report for the first time a photogenerated neutral nitrogen radical catalyzed intermolecular alkene bifunctionalization by using allyl sulfones as the source of both the carbon and the sulfone functionalities under mild conditions. The key to the success of this protocol involves the visible-light-mediated photocatalytic in situ generation of a nitrogen-centered radical from the N-(2-acetylphenyl) benzenesulfonamide catalyst, and its activation of the allyl sulfones to generate reactive species. The preliminary control experiments supported the postulated mechanism., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new synergistic multicatalytic activation mode of eosin Y has been discovered by exploiting the redox potential of its ground state and excited state. This catalytic strategy proves to be an enabling tool for visible-light-driven sequential benzylic C-H amination and oxidation of o-benzyl-N-methoxyl-benzamides when using Selectfluor as a hydrogen atom transfer (HAT) reagent and O 2 as oxidant. Efficient synthesis of a range of diversely functionalized 3-hydroxyisoindolinones can thus be achieved with good yields and selectivity at mild reaction conditions. Preliminary mechanistic studies and DFT calculations suggest that eosin Y works as a redox catalyst and photosensitizer., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)