Dragocins A—C are structurally unique marine natural products featuring an uncommon tri-oxa-tricyclic[6.2.1]undecane moiety. However, their extremely low natural abundance has hindered extensive screening of their bioactivities. We hereby describe an efficient and modular approach to synthesizing dragocins A—C and their analogues using commercially available and inexpensive anisomycin and D-ribosyl thioglycoside derivative as the starting materials. A key feature of our synthesis is the construction of the uncommon tri-oxa-tricyclic[6.2.1]undecane skeleton. This challenging architecture is achieved by the stereocontrolled formation of the β-ribofuranosidic bond and the DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone)-promoted intramolecular cross-dehydrogenative etherification at the benzylic position. Our synthesis is also characterized by the successful installation of a chlorine atom and a methoxy group at the tertiary C-4' position via a late-stage silver-catalyzed decarboxylative chlorination reaction and an electrophilic etherification reaction of the enol intermediate. Cytotoxicity evaluations of the synthesized compounds revealed demethyl dragocin A, the N-demethylated derivative of dragocin A, as a potential anticancer candidate due to its strong cytotoxicity against A549 lung, HCT116 colorectal and MCF7 breast cancer cell lines. This work also demonstrated the preliminary structure-activity relationship of this compound, setting a solid foundation for developing novel anticancer candidates.

The development of a series of shelf-stable monofluoroalkylated sulfonium ylide reagents and their reactions with a variety of O-nucleophiles including phenols, sulfonic acids, carboxylic acids, 1-hydroxy-benzotrizoles, amino acids was described. In general, monofluoroakylated sulfonium ylides were synthesized in three steps from commercially available starting materials including thiophenols, alkyl halides and dimethyl 2-diazomalonate. Reactions with the O-nucleophiles occurred under mild conditions and afforded the corresponding monofluoroalkylated ethers, sulfonates, and esters in good to excellent yields, thus providing a robust approach for the preparation of these compounds. Further expansion of monofluoroalkylation of C-terminus of peptides potentially provided modified drug-like peptides.

A regioselective C8−H alkylation of polyaromatics exampled with inert alkyl chloride is reported. The reaction proceeds via the synergistic participation of inexpensive transition metals nickel and cobalt. This approach enables the coupling of various substituted polyaromatic rings with a broad range of primary and secondary alkyl chlorides. Further synthetic applications provide a series of simple conversions to useful building blocks, suggesting its potency in the late-stage functionalization of complex molecules. Mechanistic investigation illustrates that the reaction goes through a radical process with an unusual Ni(II)→Ni(III)→Ni(I) cycle being responsible for the rate-determining C−H insertion of alkyl radicals, which are generated by the homolysis of chloroalkane with 2-electrons oxidative addition of Co(I).

The dearomatization of indole derivatives bearing amide functionalities presents a significant challenge due to the inherent stability of the amide carbonyl group, resulting from nitrogen lone-pair delocalization that imparts increased resonance stabilization. In this study, we report a visible-light photocatalytic intramolecular dearomatization of indole derivatives with amide groups, achieving the synthesis of spiroindolines via energy transfer. This method enables the efficient formation of a range of hydroxyl-substituted spiroindolines in moderate to high yields, with excellent diastereoselectivity (> 20 : 1) under mild reaction conditions. Control experiments confirmed the involvement of an energy transfer pathway in the reaction mechanism. Density Functional Theory (DFT) calculations further revealed π-π stacking interactions between the indole core and pyridine ring, along with the strengthening of hydrogen bonding between the pyridine nitrogen and hexafluoroisopropanol (HFIP) in the excited state. These interactions facilitated the energy transfer-mediated triplet excited state intermolecular proton transfer (T-ESPT), crucial for activating the otherwise amide functionality. This protocol represents a rare example of harnessing the reactivity of amide groups for dearomative transformations.

We developed a novel Pd-catalyzed carbonylation of ortho-alkenyl iodobenzenes with CO, affording a diverse array of 3-arylindenones in good to excellent yields (up to 94% yield). This methodology exhibits broad substrate scope and good functional group compatibility. The synthetic utility was demonstrated by a gram-scale reaction, diverse product derivatizations, and the preparation of an intermediate for a PPARγ agonist.

Separating propylene (C₃H₆) from propane (C₃H₈) is a complex procedure in the petrochemical sector due to the comparable characteristics of the two gases. Herein, we reported the self-assembly phenomenon of NbOFFIVE-1-Ni (KAUST-7) crystals under different synthetic routes. The material features a decreased framework strain energy compared to original KAUST-7 and exhibits completely different adsorption performance, achieving the efficient separation of C₃H₆/C₃H₈ by synergetic effect of equilibrium and kinetics. The C₃H₆ adsorption capacity was as high as 46.2 cm³·g⁻¹ (298 K, 1 bar), increasing by 53% compared to the original material. The diffusion rates of C₃H₆ were faster than C₃H₈ as confirmed by time dependent kinetic adsorption profiles. It concurrently combines an excellent C₃H₆/C₃H₈ uptake ratio of 3.1 and kinetic selectivity (96.5) for C₃H₆/C₃H₈ separation with an equilibrium-kinetic combined selectivity of 42.5. Meanwhile, it can be regenerated easily due to moderate isosteric heat of adsorption (28.7 kJ·mol⁻¹). Breakthrough experiment for C₃H₆/C₃H₈ gas mixture was conducted and confirmed the high-purity recovery of C₃H₆ over C₃H₈. Moreover, it exhibited excellent water and moisture stability and can be easily synthesized through stirring at room temperature, which confers them with great potential for industrial application.

Indoor organic photovoltaic (OPV) cells have emerged as promising candidates for harvesting energy from artificial light sources. However, the limited spectral range and low photon flux of indoor light sources restrict the photocurrent and power output of these devices. In this work, we investigate the role of a weak absorptive third component in enhancing exciton dissociation and improving indoor OPV performance. By introducing eC9-2Cl into a D18-Cl:F-BTA3 binary system, we create a ternary blend that demonstrates significant improvements in device efficiency. Transient absorption spectroscopy and time-resolved photoluminescence measurements reveal that eC9-2Cl facilitates efficient energy transfer and exciton dissociation. Under indoor lighting conditions, where eC9-2Cl acts as a weak absorptive third component, the ternary devices exhibit a power conversion efficiency increase from 24.7% to 26.2%. These findings highlight the potential of weak absorptive components in optimizing energy transfer processes and overcoming the limitations of indoor light harvesting in OPV systems.

A novel and efficient method for selective synthesis of bromo-substituted 2H-pyrroles and 3H-pyrroles has been achieved from 1,3-enynes, NBS and TMSN₃via H₂O-promoted cyclization reactions or TFA-catalyzed cyclization/2,3-shift reactions, providing a range of structurally diverse products in moderate to good yields under mild conditions.

The demands for effective assembly of structurally complex molecular scaffolds from simple starting materials are continuously growing along with the development of organic chemistry. We have developed a tandem approach that assembles simple β-chloroethylphosphane, alkynyl imines (or alkynyl ketones), and nitrones into structurally complex isoxazolidine fused phospholene scaffolds through a sequential process involving phospha-Michael addition, intramolecular cyclization, and dearomatizing [3+2] cycloaddition reactions. The isoxazolidine-fused phospholene has three heteroatoms, including a junction phosphorus atom. After removing the coordinated tungsten group, these compounds can serve as potential P-stereogenic ligands and may have biological activities. Contrary to pyrroles and furans, the aromatic 2-phosphapyrroles and 2-phosphafurans are good 2π-electron candidates in the dearomative [3+2] cycloaddition reactions due to the poor overlap of the 2p-3p orbitals of the C=P moiety.

Herein we present a novel electrochemical method for the direct decarboxylative phosphorylation of α-amino acids to α-amino phosphonates, a key structural element in various biologically active compounds. This method bypasses the need for strong chemical oxidants and 2-step processes involving preliminary conversions, making it a more straightforward synthetic tool. Key to the success of the method is to establish a microenvironment on the anode surface in an acidic solution to facilitate selective anodic decarboxylation and subsequent C–P formation. The electrosynthetic process in continuous flow ensures benign conditions and excellent scalability through continuous production with parallel reactors.

The design and development of selective recognition and sensing systems for biologically important nucleoside triphosphates (NTPs) have attracted significant attention in recent years, owing to their critical roles in cellular processes. In this study, we report the synthesis of two tetraphenylethene-based tetraimidazolium cyclophanes (1 and 2) through a one-step S_N2 reaction. These cyclophanes are capable of recognizing NTPs by forming stable 1 : 1 host-guest complexes in aqueous solution. Of particular interest, cyclophane 1 demonstrates exceptional selectivity for guanosine triphosphate (GTP), distinguishing it from other nucleoside triphosphates such as ATP, CTP, and UTP. This selective recognition is accompanied by distinct and measurable fluorescence responses, which are significantly enhanced upon binding to GTP, enabling the potential for sensitive detection. This study highlights the potential of tetraphenylethene-based tetraimidazolium cyclophanes as a highly selective and sensitive sensor for GTP, offering new insights into the design of molecular systems for the recognition of biologically relevant nucleotides.

A divergent synthesis of spiroindenes through a palladium catalyzed cycloaddition between zwitterionic π-propargyl palladium species and benzofulvenes in moderate to good yields has been disclosed along with good functional group compatibility and a broad substrate universality. This protocol features a highly regioselective switchable process between [3+2] and [4+2] cycloadditions controlled by phosphine ligands with different bite angles. The reaction mechanism has been clarified by mechanistic studies and DFT calculations, rendering that the coordination modes of the ligands with the substrates and the bite angle of the ligands play critical roles in the product regioselectivity.

Neutron diffraction studies of the low-temperature relaxor ferroelectric phases of [NH₄]M(HCO₂)₃, where M = Mn²⁺ and Zn²⁺, show that a third of the NH₄⁺ cations remain subtly structurally disordered to low temperature. All NH₄⁺ cations within the channels are well separated from each other, with significant hydrogen bonds only with the anionic M(HCO₂)₃ framework. Complementary studies of the dynamics using ²H solid state NMR and quasielastic neutron scattering indicate significant rotational motion in both paraelectric and ferroelectric phases, which evolves gradually with increasing temperature with no abrupt change at the phase transition. Nudged elastic band calculations suggest that the activation barrier for flipping between “up” and “down” orientations of the NH₄⁺ cations is low in the ferroelectric phase, with the NH₄⁺ cations primarily interacting with the framework rather than neighbouring NH₄⁺ cations. It is likely this motion that is responsible for scrambling the NH₄⁺ cation orientation locally in the ferroelectric phase. We propose that this disorder, with the same basic motion active above and below the phase transition, induces the significant dielectric relaxation in these materials. This suggests that orientational disorder may be an effective substitution for compositional disorder commonly associated with relaxor ferroelectrics in molecular materials.

Compared to the conventional trial-and-error approach, computational prediction is becoming an increasingly prominent approach in the discovery of covalent organic frameworks (COFs) with specific applications, yet it has been rarely demonstrated. Herein, we employed density functional theory (DFT) to pre-screen the electronic and optical properties of thiophene-based donor-acceptor (D-A) pairs simplified from their corresponding COF structures. Theoretical calculation illustrates the BMTB-BTTC with the highest number of thiophene units is expected to exhibit the best photocatalytic performance for hydrogen production. According to calculation prediction, four COFs have been prepared and their photocatalytic activities have been experimentally validated. Interestingly, the corresponding BMTB-BTTC-COF shows the highest photocatalytic hydrogen production rate of 12.37 mmol·g^–1·h^–1 among the four COFs. Combining the calculation and experimental results, it has been proven that the photocatalytic activity can be fine-tuned by modulating the number of thiophene units. Our study provides a new strategy for the rational design and regulation of D-A COFs to enhance photocatalytic activity through computational prediction.