Organic & Biomolecular Chemistry最新文献

Atherosclerosis (AS) is the primary pathological basis for cardiovascular and cerebrovascular events, making early diagnosis and dynamic risk assessment crucial for reducing the incidence of thrombotic occurrences. Traditional imaging techniques, such as CT, MRI, and PET, provide morphological information about plaques; however, they are limited in their ability to detect the molecular activity characteristics of these plaques, which hampers the assessment of thrombotic risk. In recent years, molecular optical probes have offered new insights into plaque activity detection by targeting specific biomarkers. However, single-target probes often produce false positive signals due to the cross-expression of biomarkers, which limits their clinical application. To overcome this challenge, dual-lock optical probes have been developed, achieving dual-target synergistic activation, which significantly enhances the specificity and signal-to-noise ratio of imaging. This article reviews the targeted imaging strategies and recent advancements in dual-lock optical probes in the context of AS, with a particular emphasis on their application in lipid droplet enrichment, oxidative stress, and specific enzymes. Although the technology still faces challenges regarding sensitivity, specificity, and multi-target design, its potential for future development is substantial. Through interdisciplinary collaboration and technological innovation, dual-lock optical probes are poised to evolve from 'imaging tools' to 'integrated diagnosis and treatment platforms', thereby advancing the precise diagnosis and treatment of complex diseases.

A novel series of Fe(III)-catalyzed crescent-shaped coumarin-appended benzo[4,5]imidazo[1,2-a]pyrimidines has been generated using a single-step multi-component approach that includes a coumarin-derived β keto ester, 2-aminobenzimidazole, and various aldehydes. The mild eco-friendly reaction conditions allowed us, for the first time, to construct a library of highly substituted benzo[4,5]imidazo[1,2-a]pyrimidine (CBPy) heterocycles with a wide range of substrate compatibility and excellent yields. This one-pot synthesis is green in nature and conforms to atom economy. The structure of one representative compound (4a) was established by X-ray crystallographic analysis. Our designed CBPys are bent in shape and capable of fitting into the minor groove of the B-DNA structure. Among all the CBPys, compound 4a exhibited the strongest binding interaction (K_d = 2.9 μM) with calf thymus DNA (ctDNA), which is known to form the B-DNA structure under the experimental conditions. A competitive binding study confirmed that the location of 4a was 43.77 Å away from the AT-rich region in the minor groove of B-DNA. It was also established that the crescent shape and the presence of coumarin were crucial for the binding of CBPys with B-DNA structures. Our results with DNA oligonucleotides of variable GC content suggest that compound 4a specifically recognizes and binds to the GC base pairs of the B-DNA structure. Thus, the CBPy class of molecules may open a new avenue for the development of novel therapeutic drugs through GC recognition.

Herein, we synthesized a new Pd-N-heterocyclic carbene (Pd-NHC) complex that featured an acenaphthoimidazolylidene (AnIm) skeleton and 2-phenyl-2-oxazoline. This catalyst exhibited extremely high efficiency in Suzuki-Miyaura couplings between N-acyl-glutarimides and organoboronic acids, affording various aryl ketones in excellent yields with a broad substrate scope and wide functional group compatibility. Notably, the reactions were completed in just 5 hours with only 0.5 mol% of catalyst. In addition, this catalytic system also enables the efficient synthesis of functional molecular intermediates. The catalyst, designed through the synergistic integration of a throw-away ligand and an extended conjugated NHC system, further demonstrates its remarkable potential.

Ubiquitin-specific proteases (USPs) play crucial roles in cellular processes and have emerged as promising therapeutic targets for various diseases, including cancer. This study utilizes a multi-faceted computational approach to investigate the binding mechanisms of small molecule inhibitors to USP7, a key member of the USP family. We combine transferable aspherical atom model (TAAM) calculations, density functional theory (DFT) analysis, and other computational tools to elucidate the electrostatic landscapes and non-covalent interactions in selected USP7-inhibitor complexes. Our findings demonstrate that electrostatic interactions are the dominant force in USP7-inhibitor binding, with charged residues contributing significantly to binding energies. Furthermore, the TAAM-based UBDB + EPMM method accurately captured the overall charge distribution, showing strong agreement with DFT calculations. We identified key residues involved in inhibitor binding, including previously overlooked contributors such as E298 and M407. The use of Hirshfeld surfaces and electrostatic potential (ESP) mapping provided detailed insights into the charge distribution and complementarity between USP7 and its inhibitors. Our results revealed that compounds with more concentrated positive charge distributions exhibited higher affinities Additionally, reduced density gradient (RDG) analysis offered further insight into the various non-covalent interactions at play. This study underscores the importance of long-range electrostatic interactions that extend beyond the immediate binding pocket. The insights gained from this work advance our understanding of USP7 inhibition and provide a valuable framework for the design of selective inhibitors targeting other members of the USP family.

An efficient and regioselective method for the introduction of a highly functionalized CF₂H-containing quaternary carbon center at the C-2 position of pyridines has been described. This method proceeds via [3 + 2] cycloaddition of β-CF₂H-1,3-enynes with pyridinium ylides, followed by a light-induced aza-Norrish II rearrangement. The salient features of this present protocol include mild reaction conditions, operational simplicity, and excellent C2 site selectivity. Furthermore, the synthetic utility of this method is demonstrated by the downstream functionalization of the resulting products.

Herein, we developed a new synthetic approach for the preparation of N-arylated 1,2,4-oxadiazin-5(6H)-ones by direct arylation with diaryliodonium salts. The reaction with symmetrical diaryliodonium salts using CuI as a catalyst proceeded in toluene in the presence of DIPEA at 60 °C with the formation of the desired products in isolated yields of 46 to 97% (20 examples). The use of more readily available unsymmetrical diaryliodonium salts required higher reaction temperatures (up to 100 °C) to achieve similar yields. The only limitation observed in reaction was with an ortho-substituted iodonium salt. In all other cases, the developed approach allowed the preparation of a broad range of N-arylated 1,2,4-oxadiazin-5(6H)-ones under mild conditions utilizing a cheap and readily available catalyst.

We have developed a novel strategy for Fe-catalyzed C-H functionalization into oxime ethers through photo-induced ligand-to-metal charge transfer (LMCT). The method avoids the need for photocatalysts and bases, utilizing a cheap and readily available catalyst under mild conditions. It offers a broad substrate scope, scalability, and high efficiency, providing a promising and cost-effective strategy for synthesizing oxime ethers from simple and abundant starting materials.

The electrochemical synthesis of 1,2-fused benzimidazoles and benzo[d]imidazoles from o-nitroanilines in an undivided cell under constant current conditions was developed. The electrosynthesis proceeded through a tandem process involving nitro reduction/C(sp³)-H amination/condensation. The method can accommodate a broad range of o-nitroanilines and results in the desired products in yields of up to 99%. A plausible reaction mechanism was proposed on the basis of controlled experiments and cyclic voltammetry (CV) analysis. The benefits of the developed method include one-pot synthesis, open-air conditions, gram-scale synthesis and no requirement for a strong reductant.

A one-pot, four-component reaction for simultaneously constructing C-Se, C-S, and C-N bonds via iron-mediated olefin 1,2-bifunctionalization was described. β-Selenylethyl dithiocarbamates were obtained highly efficiently with a wide substrate scope and remarkable regioselectivity. Notably, non-activated olefins exhibit higher reactivity in this reaction system, achieving yields of up to 99%.

A new class of axially chiral biaryl pyridine ligands have been rationally designed and concisely prepared in two steps by Skraup-Doebner-Miller synthesis. Their proof-of-concept application in an enantioselective aza-Friedel-Crafts reaction between 2-methylindoles and isatin N-Boc ketimines has been evaluated. Specifically partnered with AgOTf, the new ligands effectively catalysed the reaction with excellent enantioselectivities (up to 96% ee) and 71-94% yields, and a series of multifunctional chiral 3-indolyl 3-amino-oxindoles were successfully obtained. Compared with other noble metals and chiral ligands, this Ag(I)-B1 partner is highly stable, cost-effective, facile and easily available. This work has successfully demonstrated the good performance of a new kind of axially biaryl quinoline ligands and is the first example of a silver-catalysed enantioselective aza-Friedel-Crafts reaction between 2-methylindoles and isatin N-Boc ketimines, and has thus enriched the application of silver salts in asymmetric catalysis.