Chinese Journal of Chemistry最新文献

Due to the unique physicochemical properties of fluorine atom, the introduction of fluorine or polyfluoroalkyl group has emerged as a pivotal strategy in pharmaceutical and agrochemical design. Radical fluoroalkylation reactions stand out as a particularly efficient and innovative synthetic platform, enabling the construction of a vast array of valuable organofluorine compounds. However, a major synthetic challenge persists─the development of a unified, generalizable methodology capable of selectively forging fluorinated or fluoroalkylated molecular architectures from simple precursors remains highly desirable and challenging. Emerging strategies aim to leverage C–F bond activation, which allows for the transformation of readily available, yet often inert, polyfluorinated feedstocks into versatile fluorinated products. Described herein is a photocatalytic radical-polar crossover [3 + 2 + 1] cyclization reaction from easily available polyfluoroalkyls, enamines and 3-aminoindazole or 3-aminopyrazoles derivatives under mild conditions. Detailed mechanistic investigations reveal a sophisticated cascade pathway involving initial radical fluoroalkylation of the enamine, followed by a defluorination, and culminating in a cyclization sequence. To the best of our knowledge, this platform represents one of the very few examples for the construction of biologically important fluorine or fluoroalkyl-containing fused-ring systems under a uniform reaction condition with high efficiency and compatibility. Key to this methodology is the in-situ generation of a reactive α,β-unsaturated iminium intermediate while enabling subsequent cascade multicomponent cyclization reactions. This transformation proceeds efficiently in simple one-pot protocol with broad substrate scopes, including perfluoroalkyl halides with varying chain lengths and substitution patterns, as well as diverse nucleophilic partners. We anticipate that this transformation will establish a versatile and powerful platform for the highly efficient synthesis of diverse fluorinated scaffolds. By merging radical reactivity with polar crossover and cascade cyclization in a simple operational protocol, it opens practical and streamlined avenues for the discovery and development of diverse fluorinated compounds in medicinal and agricultural chemistry.

The efficient construction of valuable N-heterocycles is one of the most important tasks in organic synthesis. Pyrrolo[2,3-b]indoles represent a privileged skeleton, which are extensively found in natural products, pharmaceuticals and luminescent materials. Nevertheless, their synthesis suffers from pre-functionalized starting materials and multi-step synthesis. On the other hand, despite significant progress in isocyanide insertions, it remains underdeveloped for multiple isocyanide insertion initiated from inert C–O bond activation. Herein, we report an unprecedented TMSOTf-catalyzed domino reaction enabled by C–O bond activation, where double isocyanide insertion with 3-indolylmethanols and sequential intramolecular cyclization are involved to afford cyano-substituted pyrrolo[2,3-b]indoles. Isocyanides, which have generally been utilized as the sole C1 building block, are employed as both C-nucleophiles and masked N-nucleophiles to produce the cyano-substituted pyrrole skeleton. The crucial chloranil oxidant assists the electronic property variation of the indole motif, facilitating the nucleophilic attack at both benzylic and C2 positions of 3-indolylmethanols. This newly established protocol features mild conditions, good functional group tolerance and broad substrate scope. Depending on the substituent of the isocyanide, corresponding amide and cyclopenta[b]indole scaffold could also be accessed. Moreover, diverse transformations of the obtained product are illustrated, including deprotection and hydrolysis. The successful formation of various types of N-containing polycyclic compounds further demonstrates the remarkable synthetic potential inherent of the given protocol. After careful mechanistic studies, the enamine compound, generated from double isocyanide insertion with 3-indolylmethanols, is proposed as the key intermediate for this reaction.

Elucidating the structure–property–activity relationship in fluorinated COFs is crucial for advancing the rational design of high-performance COF-based photocatalysts. Despite its significance in guiding the development of next-generation fluorinated COF photocatalysts, the interplay between the quantity, spatial distribution, and integration sites of functional groups within the COF's backbone at the molecular level remains underexplored. To address this, we propose a controlled fluorination molecular engineering strategy to systematically elucidate this relationship. By precisely tuning the number and positional arrangement of fluorine atoms, we effectively enhance carrier dynamics and interfacial reaction kinetics, thereby driving efficient photocatalytic hydrogen evolution reaction. Notably, the optimized TP-COF-F-3 exhibited an apparent quantum yield of 4.09% at 500 nm, outperforming most reported COF-based photocatalysts. These findings underscore a transformative approach to the molecular design of COF photocatalysts, providing insights for the development of advanced and sustainable photocatalytic systems.

The incorporation of solid additive in photoactive layer as an effective strategy has been successfully employed to optimize the formation of a bi-continuous interpenetrating network morphology in blend bulk heterojunction, which is a critical determinant of photovoltaic performance in organic solar cells (OSCs). However, the influence of additive side-chain length on the morphological evolution remains insufficiently understood. In this work, we propose two novel solid additives, 1,3,5-tribromobenzene (TBB) and 1,3,5-tris(bromomethyl)benzene (TBMB) with different side-chain lengths. Theoretical calculations reveal that TBMB, featuring longer side-chain length, demonstrates stronger non-covalent intermolecular interaction with donors and acceptors compared to TBB, thereby favoring optimized molecular aggregation and crystallization behavior during film formation. As a result, the TBMB-treated device achieves a champion power conversion efficiency (PCE) of 17.92% in PM6:Y6 system, outperforming the TBB-treated counterpart (17.20%). Remarkably, TBMB exhibits universal effectiveness across other systems, achieving an exceptional efficiency of 20.04% in D18:L8-BO-based device. This work provides deep insights into the potential working mechanism of solid additives with precise side-chain length modulation, establishing a valuable additive side-chain effects for future research on morphology regulation in OSCs.

Although significant advances have been accomplished in the synthesis of α-chiral carboxylic acid derivatives through Wolff rearrangement of α-diazo ketones via different asymmetric catalytic mode including transition metal/photocatalysis, chiral Lewis base/photocatalysis, chiral SPA/photocatalysis and chiral NHC/photocatalysis, to the best of our knowledge, the construction of chiral carbon-heteroatom bond through Wolff rearrangement remains underdeveloped. In this paper, the first catalytic asymmetric thia-Wolff rearrangement between α-aryl α-diazothioesters and amines has been successfully achieved under cooperative rhodium/chiral phosphoric acid catalysis, which provides efficient access to synthetically valuable chiral α-sulfenylated amide architectures. This protocol features mild reaction conditions, high efficiency, excellent stereoselectivity, a broad substrate scope, scalable synthesis and versatile product functionalization, highlighting its practical value in constructing various chiral sulfur-containing compounds. Additionally, this study significantly expand the utility of diazo compounds in Wolff rearrangement for asymmetric synthesis of sulfur-containing compounds and carbene transfer reactions.

Circularly polarized luminescence (CPL) materials are attracting considerable attention due to their unique chiroptical properties and great potential in information encryption and smart sensing. However, arbitrary patterning of multicolor CPL materials with giant dissymmetry factor (g_lum > 1.5) in a scalable and customized way still remains challenging. Inspired by the cuticle of beetles, we present a general strategy for the fabrication of robust CPL films via twist-stacking (TS) assembly of highly oriented polyfluorene (PF) films. We demonstrate strong CPL amplification via the continuous TS assembly of highly oriented PF films or the heterogeneous assembly with anisotropic poly(vinyl alcohol) (PVA) layer. Moreover, by mutually perpendicular stacking of two heterogeneous PF/PVA TS patterns, dual-sided Janus displays, generating dynamic switchable CPL patterns on opposing surfaces, could be achieved. These hybrid films exclusively display decipherable information and tailorable CPL patterns under UV irradiation in darkness, while concealing all data in daylight. Thus, a multimodal information encryption system based on these biomimetic multicolored hybrid films can be devised through the programmed decryption process.

Mechanically interlocked structures exhibit remarkable adaptability and versatility due to their unique topologies, offering promising applications in molecular machines, smart materials, and energy conversion. In this work, a strategy for directing different topological configuration between metallarectangle and [2]catenane is demonstrated through the incorporation of -Br and -OCH₃ groups with distinct steric effects. Their differing size and spatial constraints promote ligand preorganization, facilitating controlled self-assembly and interlocking. Two metallarectangles (2a, 1b) and four [2]catenanes (2b, 3b, 4b, 5b) were synthesized via coordination-driven self-assembly and characterized by single-crystal X-ray diffraction, NMR spectroscopy, and ESI-TOF-MS. The photothermal properties were evaluated, revealing that 2b exhibits the highest performance, achieving a temperature change of 28 °C under 1.5 W irradiation. And the conversion efficiency ranges from 37.74% to 30.13% with varying power, attributing to the strong absorption at 730 nm and enhanced π-stacking interactions within the interlocked architecture. This study provides new insights into the rational design of functional topological complexes and highlights their potential in photothermal energy conversion.

C-Acyl glycosides are versatile building blocks for diverse C-glycosides, including hydrazone, alcohol, CF₂, and alkyl variants. However, the relatively late discovery of these in natural products and their overlooked medicinal value have resulted in significantly underdeveloped synthetic methodologies compared to other C-glycoside subtypes. Previously, the synthesis of C-acyl glycosides primarily depended on metal reagent-based addition-oxidation reactions and palladium-catalyzed cross-coupling reactions. As research advances, transition-metal (TM) catalyzed cross-coupling reactions involving glycosyl radicals have emerged as a powerful tool to access C-glycosides (C-acyl glycosides included) due to their advantages such as mild reaction conditions and controllable stereoselectivity. While recent years have seen a boom of cooperative catalysis of transition metals (particularly Pd) and chiral phosphoric acid (CPA), the analogous cooperative catalysis employing nickel (Ni) and CPA remains underdeveloped. Herein, we report a robust Ni/CPA co-catalyzed protocol for synthesizing diverse C-acyl glycosides under mild conditions. This strategy employs readily available glycosyl bromides and amides, 2-pyridyl esters, or phosphoric anhydrides, demonstrating broad functional group compatibility. A wide range of mono- and disaccharides and functionalized carboxylic acid derivatives were efficiently transformed into the corresponding products with high yields (up to 98%) and excellent stereoselectivity (α : β > 19 : 1). Furthermore, the utility of the methodology was demonstrated through the C-acyl glycosylation of various bioactive molecules and the synthesis of C-acyl disaccharides. Remarkably, the cooperative Ni/CPA catalysis significantly enhanced the yield compared to reactions without CPA. Mechanistic investigations revealed that the reaction proceeds via a nickel-catalyzed sequential addition mechanism, while DFT calculations have furnished theoretical support for the proposed pathway whereby CPA enhances the yield through hydrogen-bonding interactions.

2-Aryl and 2-acyl azole structural motifs widely exist in natural products, pharmaceuticals, agrochemicals and functional materials. Among various synthetic methods of 2-aryl and 2-acyl azoles, transition-metal-catalyzed direct C–H bond functionalization of azoles is more atom and step economical. A range of catalysts and reagents have been developed for the synthesis. However, tunable C2–H arylation and acylation of azoles employing the same reagent are rare and challenging. Thioesters as cheap and stable compounds are versatile building blocks in organic synthesis. They have been known to be effective arylation and acylation reagents when reacting with various organometallic reagents such as organozinc reagents, organoboron reagents, organosilicon reagents, organotin reagents, organoindium reagents, and organomanganese reagents. However, they were rarely used in C–H arylation and acylation reaction. In this paper, we report tunable C2–H aroylation and arylation of azoles with thioesters for the first time. Pd₂dba₃/P(m-tolyl)₃-catalyzed reaction of azoles with S-ethyl arylcarbothioates in dioxane at 80 °C in the presence of CuCl and tBuONa results in 2-aroylazoles. Similar reaction between benzoxazole or benzothiazole and S-dodecyl arylcarbothioates at 110 °C employing dcype as ligand affords 2-arylbenzoxazoles or 2-arylbenzothiazole. The method does not require activated thioesters, has a wide scope of substrates, good compatibility of functional groups, and controllable selectivity of acylation and arylation. Thioesters are easily prepared from the corresponding carboxylic acids. So, this protocol provides an alternative way to di(hetero)aryl ketones and di(hetero)aryl compounds bearing azoles from aromatic carboxylic acids.

The influence of charges on cell membrane-incorporation behaviors of channel proteins remains incompletely understood due to the structural complexity of these proteins. In this study, the influence was investigated by using asymmetric unimolecular artificial channels as simplified models. The study revealed a profound influence of terminal charge on interaction strength and kinetics. The negatively charged Ch⁻ exhibited significantly stronger interactions with lipid bilayers, demonstrated by an 83% membrane incorporation efficiency, compared to only 16% for the positively charged Ch⁺. Fluorescence correlation spectroscopy (FCS) and confocal microscopy confirmed that Ch⁻ rapidly inserts and redistributes within the membrane, while Ch⁺ shows slow, sporadic incorporation, attributed to electrostatic repulsion from positively charged lipid headgroups. Furthermore, the terminal charge critically dictated the channel's orientation within the bilayer. Using a fluorescence quenching assay, it was revealed that Ch⁻ predominantly adopts an outward-facing configuration (83%). In contrast, Ch⁺ favors an inward-facing orientation (only 19% outward). This orientation is driven by the initial anchoring of the hydrophobic end for Ch⁺, while for Ch⁻, electrostatic attraction facilitates a charged-end-first insertion. Single-particle tracking via total internal reflection fluorescence (TIRF) microscopy provided further kinetic insights: Ch⁻ aggregates adsorbed quickly and underwent dynamic redistribution, whereas Ch⁺ displayed rigid, immobilized binding once incorporated. This work unequivocally establishes molecular charge as a fundamental design parameter controlling the adsorption kinetics, binding stability, and ultimate orientation of artificial channels in lipid membranes. These findings provide essential principles for guiding the rational design of next-generation membrane-active therapeutic agents and biomimetic sensors.