Latest ArticlesThis work describes intermolecular acylfluorination of gem-difluoroenynes using acyl fluorides as both acyl source and fluorine source. Trifluoromethyl-substituted allenones or furans could be selectively achieved via phosphine and silver catalysis. These approaches exhibit high regioselectivity, atom economy and broad functionality tolerance.
Delayed or non-healing of diabetic wounds is a significant complication, often attributed to high glucose-induced M1 macrophage accumulation, impaired angiogenesis, and reactive oxygen species (ROS) buildup. Addressing this, we introduced a strontium polyphenol network microneedle patch (SrC-MPNs@MN-PP) for percutaneous drug delivery. This patch, formulated with polymer poly(γ-glutamic acid) (γ-PGA) and epsilon-poly-L-lysine (ε-PLL), incorporates strontium polyphenol networks (SrC-MPNs). The release of chlorogenic acid (CGA) from SrC-MPNs not only neutralizes ROS, but strontium ions also foster angiogenesis. Consequently, SrC-MPNs@MN-PP can ameliorate the diabetic wound microenvironment and expedite healing.
Sulphur (S)-template method based on conventional slurry-casting method has been developed to produce porous silicon (Si) electrodes. The facile fabrication technology is suitable for current production line and expected to be widely applied to various electrode materials under large volume change during operation. Specifically, S particles as template agent are mixed with active material Si, carbon conductor and binder forming uniform slurry. After casting and drying, the electrodes are immersed in carbon disulfide solution to remove S particles rapidly, generating pores in-situ at the original position of S particles. Electrochemical analysis shows that the pores inside electrodes are able to shorten lithium ion diffusion paths, reduce normal expansion rate and decrease formation of cracks in the Si electrode (2 mgSi/cm2), demonstrating a reversible capacity of 951 mAh/g at 0.5 A/g after 100 cycles (with a capacity retention of 99.5%) and a capacity of ~826 mAh/g at 2 A/g.
Heterogeneous porous carbon (PC) materials have gained unique importance in the catalysis community due to their captivating properties, including high specific surface area, tunable porosity, and functionality. PC can play a prominent role in the sustainable synthesis of functional heterocycles, as they are a low-cost alternative while being an efficient and user-friendly material. This review examines the preparation and applicability of these carbonaceous materials used as catalysts or support for biologically active heterocycles synthesis, including hydrogenation, oxidation, oxidative dehydrogenation, cross-coupling, and other organic reactions. Moreover, the challenges, potential future development directions, and opportunities in the synthesis of potent bioactive heterocycles over PC materials have been addressed. This review will inspire further research to explore novel PC materials and their implications in heterocyclization.
An eco-friendly and practical method for the clean preparation of 5-amino-1,2,4-thiadiazoles was developed. With WS2 as the semiconductor photocatalyst, both TEMPO and O2 (in air) as the redox catalysts, a variety of thiadiazoles were semi-heterogeneously formed in high to quantitative yields and could be easily collected by CPME extraction and rinsing. Furthermore, the catalytic system can be reusable for at least 5 reaction runs.
The development of low-cost, earth-abundant and environmentally benign transition metal catalysts, which can catalyze multiple different types of asymmetric reactions, is an important objective in modern asymmetric catalysis. Herein we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions: allenylic substitution of racemic allenic ethers, 1,4-hydroalkylation of prochiral 1,3-enynes and double alkylation of newly designed enynyl ether reagents. Three methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3,5-dione unit, which is widely present in drugs and biologically active molecules with versatile pharmacological activities.
Highly branched poly(β-amino ester)s (HPAEs) have emerged as a safe and efficient type of non-viral gene delivery vectors. However, the presence of inactive terminal secondary amine groups compromises their gene transfection capability. In this study, HPAEs with similar topological structures and chemical compositions but varying numbers of terminal secondary 4-amino-1-butanol (S4) and secondary/tertiary 3-morpholinopropylamine (MPA) groups were synthesized. The results demonstrate that an increased number of secondary/tertiary MPA groups in-situ significantly enhances the DNA binding capability of HPAEs, leading to the formation of smaller HPAE/DNA polyplexes with higher zeta potential, ultimately resulting in superior gene transfection efficiency in bladder epithelial cells. This study establishes a simple yet effective strategy to maximize the gene transfection potency of HPAEs by converting the inactive terminal groups in-situ without the need for complex modifications to their topological structure and chemical composition.
Diradical polycyclic hydrocarbons (PHs) have unique open-shell structures and interesting physical properties. However, owing to high reactivity of unpaired electrons, such open-shell organic diradicaloids are usually less stable than closed-shell systems, limiting their practical applications. In this study, we report P=O-attaching of diradical PHs as a new strategy to enhance their stability while maintaining diradical properties. Three P=O-attached PHs containing the indeno[1,2-b]fluorene, fluoreno[3,2-b]fluorene and indeno[2,1-b]fluorene π-skeletons, respectively, were designed and synthesized. As theoretically and experimentally proved, two of them have the relatively large diradical characters and open-shell singlet diradical nature. In comparison to their all-carbon analogues, the attached electron-withdrawing P=O groups endow them with much lower LUMO/HOMO energy levels but preserved magnetic activities and physical properties, such as thermally accessible triplet species and multi-redox ability. Moreover, the P=O groups effectively decrease their oxidation activities and thereby lead to their remarkably excellent ambient stabilities. Thus, this P=O-attaching strategy will be applicable to other diradical PH systems and may promote the generation of stable organic diradicaloids for radical chemistry and materials.
Organic thermoelectric (OTE) materials and devices have garnered significant attention in the past decade for flexible and wearable electronics. Due to the numerous combinations of different backbones, side chains, and functional groups for polymer molecules, further efficient developments of high performance OTEs rely on reverse and rational molecular design as well as fundamental understanding to the structure-property relationship, which both require precise theoretical input. Recently, many theoretical efforts and progresses have been made to predict TE properties and develop high performance OTE materials. Here, we present first the general methods and principles for OTE theoretical calculations. Subsequently, the latest theoretical advances regarding the effects of molecular design, chemical doping, ambipolar charge transport etc., to TE conversion are carefully reviewed. These theoretical advances not only significantly deepen the fundamental understanding of OTEs, but also provide precise guidance to the molecular design of OTE materials. Finally, we propose several perspectives for future theoretical investigations of OTEs.