Photochemical synthesis technology has gained attention in the field of synthetic chemistry due to its mild reaction conditions, simple equipment, and utilization of light energy. However, photochemical synthesis experiments are rarely incorporated into undergraduate organic chemistry laboratory courses. Fluorine-containing nitrogen heterocycles are widely present in natural products and bioactive molecules, serving as important intermediates in organic synthesis. Based on our team’s recent research achievements, a comprehensive experiment for the photochemical synthesis of difluoropyrroles has been designed. This experiment encompasses the preparation of substrates and products, structural characterization, and analysis of photochemical synthesis. It aims to enhance students’ skills in organic synthesis and structural analysis, while also sparking their interest in organic chemistry experiments. Furthermore, it plays a significant role in cultivating students’ innovative consciousness and promoting the concept of “green synthesis” by incorporating scientific research outcomes into organic chemistry laboratory teaching.

Radical philicity and polar effects are key concepts underpinning radical reactivity and selectivity. In general, the radical species can be divided into two classes, namely, electrophilic and nucleophilic, on the basis of its reactivity, atom electronegativity, and stability of the resulting species through electron gain or loss. In this article we aim to establish guidelines for understanding radical philicity from different carbon-centered and heteroatom-centered radicals and we accompany our discussion with representative synthetic examples.

The substitution of heteroaromatics by nucleophilic carbon-centered radicals is known as the Minisci reaction. In this study, efficient synthesis of 4-(benzo[d]thiazol-2-yl)butan-2-one was achieved through radical alkylation between 1-methylcyclopropan-1-ol and benzo[d]thiazole under silver-catalyzed and aqueous conditions. This method offers advantages such as simple operation procedures, mild reaction conditions, and excellent atom-economy. Undergraduates have successfully validated this reaction, making it a suitable candidate for a teaching experiment that effectively supplements knowledge in radical chemistry.

The persistent radical TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl) can be used in cooperating with semiconductor photocatalysis to promote electron and proton transfer during selective oxidation reactions. TEMPO is introduced into the reaction system as a redox mediator through rational design to improve efficiency. Both titanium dioxide and covalent organic frameworks can construct cooperative photocatalysis with TEMPO to activate diradical molecular oxygen for achieving the selective oxidation of organic substrates like amines and sulfides driven by visible light.

The structure and reactivity of cyclopropane are crucial topics in the undergraduate organic chemistry curriculum. However, current textbooks typically only address ionic ring-opening addition reactions, such as those involving hydrogen gas and halogens. This paper introduces the radical ring-opening reactions of cyclopropane facilitated by visible light photoredox catalysis, summarizing the latest advancements in the field. By presenting representative, easily understandable examples, this study aims to enhance undergraduate students’ comprehension of radical ring-opening reactions of cyclopropane. Integrating foundational knowledge with cutting-edge chemical research not only fills knowledge gaps in existing textbooks but also transforms advanced scientific findings into valuable educational resources. This approach broadens students’ knowledge base, enhances their learning interest, and improves overall learning efficiency.

The synergistic use of photoredox and copper catalysis in free radical reactions has gained extensive application in organic synthesis due to its high yield, mild reaction conditions, excellent functional group compatibility, and environmental friendliness. In alignment with the principles of green and sustainable development, we have efficiently synthesized high-value nitrile compounds from industrial raw materials, such as olefins, commercially available trimethylcyanosilane, and water under mild conditions using visible light irradiation. This comprehensive experiment encompasses a variety of techniques, including anhydrous and anaerobic operations, thin-layer chromatography (TLC), flash column chromatography, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) analysis. Additionally, the experiment is characterized by easily accessible starting materials, mild reaction conditions, and high reproducibility, eliminating the need for complex instrumentation. This ensures that students can enhance their experimental skills, foster their innovative capabilities, and gain exposure to the forefront of organic chemistry. Hence, this experiment holds significant practical and educational value.

The 1,2-difunctionalization of olefins via radical pathways is a crucial method in organic synthesis for the direct formation of C—X (X = C, N, O, etc.) bonds from olefins. This approach offers several advantages, including high regioselectivity, step economy, and atom economy, making it compatible with the principles of green chemistry. The development of simple and efficient methods for constructing carbon-oxygen bonds is a significant area of interest in organic chemistry due to the prevalence of organic functional compounds containing these bonds. This review summarizes the recent progress in constructing carbon-oxygen bonds concurrently with carbon-carbon, carbon-nitrogen, carbon-sulfur, and carbon-halogen bonds. Additionally, the article discusses the future directions for research in this field.

Electrochemical organic synthesis represents a crucial frontier in organic chemistry research, offering mild conditions and environmental friendliness. However, it has yet to be widely adopted in undergraduate laboratory teaching. This experiment is designed based on recent research findings to facilitate the nucleophilic aromatic substitution reaction of benzoic acid and 4-fluoroanisole under electrochemical conditions. The experiment includes four main components: product preparation, purification via column chromatography, structural characterization, and cyclic voltammetry (CV) analysis. The objective is to enhance students’ comprehensive experimental skills, introduce them to advanced organic chemistry topics, and instill an understanding of green chemistry principles.

Organic synthetic chemistry is an elective course for undergraduate chemistry majors at universities. Radical chemistry represents a cutting-edge area of research field within organic chemistry. Addressing the current gap in students’ understanding of radical chemistry concepts in foundational organic chemistry, this study proposes an interactive teaching approach guided by a “moral education” framework, aiming for “deep learning”, and taking “scientific frontiers” as a backdrop for cultivating national confidence. The course design encompasses a knowledge module on radical reactions, facilitating in-depth exploration through various aspects, including the introduction, development, and expansion of radical concepts, as well as the application of catalytic asymmetric radical reactions. This approach aims to integrate ideological and political elements into the organic synthesis curriculum, establish a repository of case studies for ideological education, and offer a novel perspective on the integration of organic synthesis teaching with ideological and political education for undergraduate students.

The decarboxylative halogenation of carboxylic acids via radical pathways, initially discovered by Borodine and further developed by Hunsdiecker, represents a classic transformation of carboxylic acid functional groups. The traditional Hunsdiecker reaction involves the pre-preparation of anhydrous silver carboxylate salts, which react with bromine to produce the desired brominated products. Since its inception, the synthetic utility of the Hunsdiecker reaction has attracted significant attention and has been extensively investigated by chemists. Considerable efforts have been directed towards enhancing the efficiency, practicality, and cost-effectiveness of this reaction. In the past decade, a series of novel Hunsdiecker-type reactions have emerged, notably including the recent advancements and innovations made by the group of Prof. Li. This article aims to review the developments in radical decarboxylation and halogenation reactions achieved by chemists in recent years.

Radical reactions are pivotal in organic chemistry, playing a significant role in synthetic methodologies. Radical-mediated 1,5-hydrogen atom transfer (HAT) represents an effective strategy for the functionalization of remote unactivated C(sp³)―H bonds, exhibiting excellent regioselectivity and atomic economy. Recent studies in this area have achieved breakthrough results. This review draws upon the allusion of “长辔远驭” (Chang Pei Yuan Yu) to provide a detailed discussion on the direct functionalization of remote C(sp³)―H bonds initiated by radical-induced 1,5-HAT under metal-catalyzed, visible light-catalyzed, and synergistic catalytic conditions.

This study presents a nitrogen-centered radical reaction designed for undergraduate experimental teaching. By performing the same experiment under three different conditions, students become more familiar with the experimental procedures while deepening their understanding of the characteristics of radical reactions. The experiment is characterized by its simplicity, high efficiency, and reproducibility. Additionally, it incorporates elements of curriculum ideology and politics, such as energy conservation, emission reduction, and green chemistry, thereby fostering students’ scientific research and innovation skills. This reaction is well-suited for promotion as an undergraduate teaching experiment.

In today’s era, “health preservation” is prevalent. “Antioxidation” has become a hot topic, and anti-aging is a part of antioxidants. This article takes a fantastic journey of free radicals, uncovering the reasons behind daily phenomena such as wrinkles on the skin, hardening of plastic products after prolonged use, and spoilage of edible oils. At the same time, correct antioxidant methods were proposed. Through this paper, we hope to reduce people’s anxiety about aging appearance and protect their physical and mental health. In contemporary society, the concept of “health preservation” is gaining prominence, with “antioxidation” emerging as a significant topic of interest, particularly in the context of anti-aging. This paper embarks on a captivating exploration of free radicals, revealing the underlying mechanisms behind everyday phenomena such as the appearance of wrinkles on the skin, the hardening of plastic products with prolonged use, and the spoilage of cooking oils. Additionally, effective antioxidant strategies are proposed. Through this work, we aim to alleviate concerns regarding the aging process and promote both physical and mental well-being.

The copper/dioxygen catalyzed radical reactions that features high reaction efficiency, mild reaction conditions, good functional group compatibility and environmental friendliness, has been widely applied in organic synthesis. Inspired by the principles of green and sustainable development and drawing on our recent research findings, we designed a comprehensive experiment for the copper/dioxygen-catalyzed cleavage of C―C bonds in amides to synthesize asymmetric urea derivatives at room temperature. This experiment features readily accessible starting materials, mild reaction conditions, ease of execution, and does not require complex instrumentation. It effectively fosters students’ innovative abilities while providing insights into the forefront of radical chemistry. Consequently, this experiment holds significant practical and educational value.

Aryl radicals, pivotal intermediates in myriad chemical reactions due to their distinct electronic structure and remarkable reactivity, present formidable challenges in terms of efficient generation and directed transformation. This paper highlights recent advancements where chemists have effectively tackled this challenge by harnessing rapidly evolving photochemical and electrochemical techniques, enabling their use in diverse C―H arylation processes among other syntheses. The innovative substrate activation methods and subsequent reaction control strategies not only enrich the undergraduate curriculum in radical chemistry but also deepen students’ comprehension of radical reaction mechanisms.

Phenols, produced at an annual volume exceeding ten million tons, are widely used in various key organic transformations due to their low cost. In introductory chemistry courses, the reactions of phenols typically involve substitutions at the electron-rich aromatic ring or the hydroxyl oxygen, leaving the inert C―O bond intact in the final products. To expand the utility of phenols, researchers have developed metal-catalyzed strategies that cleave the C―O bond by introducing activating groups at the oxygen atom, enabling efficient deoxygenative coupling reactions. However, these methods often require harsh conditions and may result in metal contamination, limiting their use in pharmaceutical and other sensitive applications. To address these limitations, recent studies have demonstrated that simple phenol derivatives can selectively cleave the inert C―O bond under mild conditions, using light or electricity to generate aryl radicals. The high reactivity and selectivity of these radicals enable novel and efficient chemical transformations, offering new strategies for the application of phenols in organic synthesis. This paper reviews recent advancements in using trifluoromethanesulfonates, phosphates, and carbonates of phenols as aryl radical precursors, discussing the challenges and breakthroughs in constructing complex molecules with high precision. This review aims to broaden the knowledge of advanced students in the field.

The synthesis of cyclohexene is a classic experiment in basic organic chemistry laboratory courses. Utilizing cyclohexene as a substrate, we demonstrate the significant role of radical reactions in modern chemistry by performing electrochemical C―H bond functionalization. In this study, we achieve the oxidation of the C―H bond in cyclohexene under electrochemical conditions using N-hydroxyphthalimide as both a hydrogen atom transfer catalyst and an oxidizing agent, eliminating the need for additional oxidants. The process employs inexpensive and readily available electrode materials, and the solvent used can be recycled. Furthermore, students can gain fundamental insights into this C―H bond oxidation reaction through electrochemical analyses and bond dissociation energy assessments. The reaction conditions are mild and safe, with a duration suitable for undergraduate laboratory courses. The reproducibility of this method has been validated by multiple undergraduate students.

Photocatalytic synthesis has garnered significant attention over the past decade due to its mild reaction conditions, high efficiency, and excellent tolerance for functional groups, as well as its selectivity. While most undergraduate organic synthesis experiments focus on thermal reactions, radical photochemistry — an area at the forefront of research — has received less emphasis. The photoredox α-amino C(sp³)―H arylation reaction has been developed to produce valuable α-arylcycloalkylamines. This reaction is not only green and efficient, but also straightforward, making it accessible and comprehensible for students. Its inclusion in the curriculum enriches the content of photocatalytic reactions in basic organic chemistry courses and lays a solid foundation for further exploration in organic photochemistry.

Incorporating cutting-edge scientific examples into classroom teaching not only clarifies the practical value of fundamental research but also sparks students’ curiosity and fosters their enthusiasm for exploring advanced topics. Radical chemistry, a critical area of organic chemistry, is known for its high reactivity, complex mechanisms, and diverse products, making it both a key and challenging topic in organic chemistry education. In recent years, organic radicals, with their unique narrow-bandgap structural properties, have garnered significant attention in biomedical research, resulting in breakthroughs in diagnostics and treatment. However, as chemical species with unpaired electrons, radicals often exhibit kinetic and thermodynamic instability, which constrains their broader practical use. This article discusses the structural types and synthesis strategies for stabilizing organic radicals and explores their potential applications in precision biomedical diagnostics and photo-triggered therapies. Integrating the latest research on radicals into classroom instruction enhances students’ comprehension and expertise in this field.

Visible light catalysis offers several advantages, including mild reaction conditions, high efficiency, low energy consumption, and broad functional group compatibility, making it a powerful tool in synthetic chemistry. Nitrogen-containing heterocyclic frameworks and fluorinated functional groups are widely present in bioactive molecules. Selectively introducing a difluoromethyl group (CF₂H) into nitrogen heterocycles can significantly influence the pharmacological and pharmacokinetic properties of lead drug candidates. This paper reports a visible light-mediated radical difluoromethylation of caffeine, employing [bis(difluoroacetoxy)iodo]benzene as the difluoromethylating reagent. The reaction proceeds without the need for transition metals or oxidants, is straightforward to perform, and easy for students to learn, offering both educational and practical value.

The oxidation of alcohols to aldehydes is a fundamental reaction in organic synthesis. Introducing this reaction as a core experiment in organic chemistry holds significant educational value, helping students grasp textbook concepts and familiarize themselves with essential laboratory techniques. This study presents the photocatalytic oxidation of β-naphthylmethanol, catalyzed by tetrabutylammonium decatungstate (TBADT) with oxygen as the oxidant, resulting in the successful synthesis of β-naphthaldehyde. The experiment is straightforward, yields high product output, and proceeds under mild conditions, making it highly suitable for undergraduate laboratory courses.

Carbon radicals are crucial reactive intermediates in organic chemistry. Investigating the structures and stabilities of various carbon radicals is essential for elucidating organic reaction mechanisms and understanding reaction selectivity. In this study, we utilize density functional theory (DFT) to examine the structural characteristics and stability of different alkyl radicals, providing a strong theoretical basis for comprehending related reactions. This research aims to facilitate students’ understanding of the structural features and stability trends of carbon radicals. Furthermore, we delve into the selectivity of alkane chlorination reactions, enhancing students’ comprehension of radical substitution reactions in alkanes and offering a more comprehensive understanding of this topic.

Free radicals are fundamental in organic chemistry, forming the cornerstone of organic reactions alongside other high-energy intermediates such as carbocations, carbanions, and carbenes. Among these, oxygen-centered radicals represent a particularly unique and important class of active intermediates. Their distinctive properties not only enable them to initiate a variety of organic reactions but also drive extensive research in healthcare and environmental protection. This article aims to thoroughly analyze and highlight the physicochemical properties and diverse synthesis strategies of four key oxygen-centered radicals: triplet oxygen (·O₂·), hydroxyl radical (HO·), superoxide anion radical (O₂^-·), and alkoxy radical (RO·). Additionally, it elucidates their specific application examples and significant impacts in the field of organic synthesis.

In recent years, asymmetric free radical reactions catalyzed by organocatalysts have garnered significant attention in the field of organic synthesis. This strategy exhibits mild reaction conditions, and demonstrates excellent regioselectivity and stereoselectivity. Notably, the rapid development of visible light catalysihas provided a new avenue for enhancing these reactions. This review highlights recent progress in asymmetric free radical reactions that combine photocatalysis with organocatalysis: (1) visible light–chiral amine cooperative catalysis, (2) visible light–carbene cooperative catalysis, and (3) visible light–hydrogen bonding catalysis.

Rearrangement reactions are fundamental to the formation of complex molecular structures in organic chemistry. In contrast to traditional ionic rearrangements described in textbooks, research on free radical rearrangements has been gaining increasing attention in recent years. This area of study has become a focal point for organic chemists. Consequently, incorporating free radical rearrangement reactions into organic chemistry curricula is essential. This paper examines the migration of functional groups in free radical rearrangement reactions. Through a comparative analysis of reaction types, intermediate formation, reaction conditions, and product outcomes, the paper provides a detailed explanation of the mechanisms behind free radical functional group migration reactions and their applications in organic synthesis. During the teaching process, both instructors and students collaboratively elevate the complexity of fundamental organic chemistry concepts. This paper advocates for the inclusion of free radical rearrangements in textbooks and classroom teaching, integrating ideological and political elements to inspire students with the scientific innovation and patriotic spirit of China’s new generation of chemists.

Rearrangement reactions are a key focus in undergraduate organic chemistry education. However, while ionic rearrangement reactions and pericyclic reactions are extensively covered, radical rearrangement reactions are rarely introduced in university curricula. This gap often results in an incomplete understanding of the subject by students. This article aligns with recent developments in the field and presents an overview of visible-light photocatalyzed radical rearrangement reactions, framed through the lens of functional groups, which undergraduates are well-prepared to grasp. By selecting representative reactions that are both illustrative and accessible to undergraduates, and by analyzing them from a mechanistic standpoint, this paper aims to bridge the gap between foundational teaching and cutting-edge chemistry. This approach not only addresses gaps in textbooks but also broadens students' knowledge, fostering their curiosity and enthusiasm for exploring the mysteries of chemistry.