Nitrogen-containing bridged-heterocycles and indoles are key subunits of many natural products and pharmacologically active molecules. We herein present a bimetallic Cu/Ir catalyzed asymmetric allylation of ketimine esters and (E)-4-indolyl allyl carbonates followed by acid-promoted Pictet-Spengler cyclization sequences, enabling stereodivergent synthesis of chiral indole fused 9-azabicyclo[4.2.1]nonanes containing an eight-membered ring with one tertiary and two quaternary stereogenic centers. This one-pot sequential protocol features step economy, good substrate tolerance, and excellent stereoselective control.

Accurate prediction for chemical reaction performance offers optimal direction for synthetic development. To this end, we present a novel multi-modal model called MMHRP-GCL to achieve the prediction of homogeneous chemical reaction yield, enantioselectivity, and activation energy by fusing the information from the text and graph modalities, requiring only 8 simple descriptors and Reaction SMILES obtained without high-cost DFT computation, and capable of managing reactions involving a fluctuating number of molecules. Experimental results on 4 datasets show that MMHRP-GCL outperforms at least 7 generalized SOTA methods. Ablation study confirms the critical roles of the complementation of graph and text modalities, as well as the significance of modality alignment and atomic features in prediction. Albeit there is still room for improvement in the interpretation of atomic relationships, the model has a remarkable ability to identify important atoms. A statistically interpretable study of the feature importance and a test on challenging dataset further demonstrates the utility and potential of the model. As a high-accuracy, low-cost, interpretable, and general multi-modal model, MMHRP-GCL provides valuable guidance on the design of forward predictors for homogeneous catalytic reactions.

Herein, an intermolecular palladium(II)-catalyzed regioselective [4+2] benzannulation reaction capable of converting 2-pyridones into quinolinones was developed using electron-deficient alkenes as two-carbon units. An examination of the reaction mechanism indicated that the extension from 2-pyridone to quinolinone was likely facilitated through a series of sequential C—H activation reactions or 6π electrocyclization, culminating in dehydrogenative aromatization. This method of diversity-oriented synthesis of quinolinone derivatives is characterized by a broad substrate scope, atom economy, and excellent chemical selectivity. In addition, these quinolinone derivatives exhibit fluorescent absorption within the visible-light spectrum, which makes them suitable candidates for the development of innovative fluorescent probes.

Atherosclerosis is a lipoprotein-driven disease. In-depth understanding of pathology and accurate identification are particularly important in clinical assessment and treatment due to the irreversibility of atherosclerotic plaque formation. Atherosclerosis is not only accompanied by lipid droplets accumulation but also closely related to inflammation, which is accompanied by excessive reactive oxygen species (ROS) and changes in microenvironment. However, there is still a lack of a simple and rapid detection platform to simultaneously evaluate multiple indicators of atherosclerosis in multiple channels. In this study, we propose a multicolor imaging probe Cy7P-B for polarity, H₂O₂ and lipid droplets to evaluate atherosclerotic plaques in vivo. Cy7P-B is sensitive to environmental polarity and can monitor polarity changes by near-infrared ratio. Moreover, Cy7P-B has H₂O₂/lipid droplets dual-analyte sequential activation characteristics. Based on the multifunctional properties of Cy7P-B, the classical biomarkers of atherosclerotic plaque, lipid accumulation and up-regulation of oxidative stress are effectively detected in atherosclerotic plaques, and more importantly, the change of aortic polarity in atherosclerosis was detected for the first time. This work provides a general molecular design approach for multi-species imaging of AS, which is helpful for effective cardiovascular disease stewardship.

The use of CO₂ as a renewable C1 source for the synthesis of value-added chemicals can contribute to a more sustainable chemistry. In this work, a nickel-catalyzed amide-directed carboxylation of aryl C−F bonds with CO₂ has been developed. The reaction is switchable controlled by LiCl to react with one or two molecules of CO₂ to afford valuable phthalimides or α-hydroxycarboxylic acid derivatives. Further study shows that the reaction is a step-by-step process. The first step is a nickel-catalyzed carboxylation of aryl C−F bonds with CO₂ and tandem cyclization to afford phthalimides. The second step is a nickel-catalyzed C−N bond carboxylation of phthalimides with CO₂, and intramolecular nucleophilic addition of amide anion to the carbonyl. The carboxylation of phthalimides with CO₂ is also developed based on this reaction. The work features inert C−F bond functionalization, amide C−N bond activation, and multiple CO₂ incorporation. Mechanistic studies indicate that the azanickelacycle intermediates play an important role, and LiCl facilitates the reduction of Ni(II) to Ni(I) and promotes the carboxylation with the second molecule of CO₂. This protocol provides an efficient route for C−F bond functionalization under mild conditions via the chemical fixation of one or two molecules of CO₂.

Planar-chiral cyclophanes with carbon-centered chirality are important targets in natural products and pharmaceuticals. However, synthesizing such planar chiral cyclophanes with two stereogenic elements via a one-step asymmetric reaction remains a formidable challenge. Herein, we present an efficient kinetic resolution method for synthesizing planar-chiral [n]cyclophanes with carbon-centered chirality. This is achieved through the enantioselective allylation of racemic aldehyde [n]cyclophanes catalyzed by Bi(OAc)₃ and chiral phosphoric acid. The reaction delivers planar-chiral [n]cyclophanes and multiple chiral [n]cyclophanes with high yields and excellent enantioselectivities, showcasing remarkable kinetic resolution efficiency (s factor up to 292). The broad substrate scope, scalability, and potential for derivatization highlight the value of this methodology. DFT calculations have also been performed to provide insights into the origin of the experimentally observed diastereo- and enantioselectivity for this reaction.

Herein, we present the first examples of asymmetric reductive 1,4-dicarbofunctionalization of 1,3-dienes and 1,5-dicarbofunctionalization of vinylcyclopropanes, which proceed under the catalysis of a chiral nickel/bis-imidazoline complex using alkyl halides and aryl iodides or alkenyl bromides as the electrophilic coupling partners. In these highly enantioselective transformations operating in a radical relay mechanism, the C(sp³)- and C(sp²)-type carbo-moieties are respectively installed on the terminal and internal position with a newly formed olefinic unit in high E-selectivity.

Three three-dimensional Hofmann-type metal-organic frameworks (MOFs) [Fe(bpn){Ag(CN)₂}₂]·Ph₂S (1·Ph₂S, bpn = 1,4-di(pyridin-4-yl)naphthalene, Ph₂S = diphenylsulfide), [Fe(bpn){Ag(CN)₂}₂]·Ph₂SO (1·Ph₂SO, Ph₂SO = diphenylsulfoxide) and [Fe(bpn){Ag(CN)₂}₂]·Ph₂SO₂ (1·Ph₂SO₂, Ph₂SO₂ = diphenylsulfone) were synthesized by employing sulfur-containing aromatic guests varying in oxidation states. 1·Ph₂S performed a complete four-step spin crossover (SCO) behavior with the sequence of HS↔~LS_1/3HS_2/3↔~LS_1/2HS_1/2↔ ~LS_2/3HS_1/3↔LS, while an incomplete two-step SCO profile with the sequence of HS↔~LS_1/3HS_2/3↔~LS_2/3HS_1/3 and a faint SCO behavior at low temperature for 1·Ph₂SO and 1·Ph₂SO₂. Photomagnetic experiments indicate the light-induced excited spin-state trapping (LIESST) effect in 1·Ph₂S and the bi-directional LIESST effect for 1·Ph₂SO and 1·Ph₂SO₂. Variable-temperature structural analyses reveal the evolution of host-guest synergy and highlight the mechanism of adaptive deformation of guests mediated by phenyl rotation amid spin transition. As the oxidation state of sulfur-containing guests increases, the host-guest cooperation within the lattice is limited by the steric effect, which stabilizes the high-spin state and consequently diminishes the SCO capability in this system. These results demonstrated herein open a new perspective on host-guest chemistry within SCO frameworks.

Herein, we have developed a facile method for the synthesis of various polysubstituted pyridine derivatives through selective 6π-electrocyclization of N-vinyl-α,β-unsaturated nitrones. It was found that gold catalysts promoted carbon-6π-electrocyclization of N-vinyl-α,β-unsaturated nitrones to afford 6-alkenyl pyridine N-oxides in 43%—75% yields, whereas copper catalysts facilitated oxygen-6π-electrocyclization to give 6-epoxy pyridines in 41%—83% yields. The present method features broad substrate scope, good functional group tolerance, high cyclization selectivity, and diversity of polysubstituted pyridine scaffolds.

To overcome the depurination challenges associated with classical DNA synthesis methods, this study introduces a novel approach using fluoride-sensitive, triisopropylsilyl (TIPS)-protected phosphoramidite monomers for the efficient synthesis of short single-stranded DNA. The bulky TIPS group selectively protects the 5'-hydroxyl group of nucleosides and can be rapidly removed under mild, non-acidic conditions using fluoride ions, minimizing side reactions. Four novel TIPS-protected phosphoramidite monomers were synthesized and characterized, achieving >99% deprotection efficiency. These monomers were applied to the solid-phase synthesis of a 5-mer ssDNA sequence, yielding an overall efficiency of 99% for each cycle. The strategy demonstrates significant potential for improving the reliability and scalability of oligonucleotide synthesis, offering a promising alternative for applications in synthetic biology and nucleic acid research.

Cross-coupling reactions between aryl halides and thiolates or selenolates typically require transition metals, photocatalysts, strong bases, or/and malodorous thiols/selenols, with various mechanisms proposed. This study aims to leverage a new application of neutral ChB to address these challenges and enable a very simple photoinduced cross-electrophile C—S/Se coupling using readily available chalcogen electrophiles. Mechanistic investigations have revealed the important role of neutral ChB in facilitating single electron transfer processes, thereby enabling the generation of thiolates/selenolates from stable chalcogen electrophiles and α-aminoalkyl radicals, which possess the capability to abstract halogen atoms from aryl iodides. Moreover, the study provided support for the radical nucleophilic substitution mechanism.

To gain insights into the potential of thianthrene (TA), its substituent effects were systematically studied on the room-temperature phosphorescence (RTP) properties, including the electron-donating and electron-withdrawing substituents at 1- and 2-positions of TA, respectively. Both theoretical and experimental investigations show that the 2-position electron-withdrawing substituents greatly enhance RTP performance than the 1-position substituents, while the situation is exactly the opposite for electron-donating substituents. Compared with the 1-position substitution, the 2-position electron-withdrawing substituents induce the higher RTP radiation rate and lower non-radiation rate, in favor of the enhancement of RTP efficiency. Furthermore, the introduction of phenylene into the 2-position substitution greatly suppresses the non-radiation, resulting in the simultaneously improved RTP efficiency and elongated lifetime. Finally, using these RTP materials, the dynamically reversible operations of information (write-read-erase) are realized, as well as the encryption and time-dependent decryption demonstration. This work not only provides a better understanding of structure–property relationship on TA-based RTP materials, but also suggests an intramolecular structural modification strategy to improve the performance of pure organic RTP materials.

Substantial progress has been made over recent years in visible light-driven dual photoredox/copper catalyzed atom transfer radical polymerization (photo-ATRP) through the design of photocatalysts (PCs) and the optimization of reaction conditions. However, it remains challenging to achieve efficient photo-ATRP with low loadings of both photocatalyst and copper(II). In this study, two donor-acceptor organic PCs based on pyrazino[2,3-f][1,10]phenanthroline were successfully used to achieve efficient Cu(II)-mediated photo-ATRP. These organic PCs exhibit excellent visible light absorption capabilities and thermally activated delayed fluorescence (TADF) properties. Under blue light irradiation, the PCs facilitated highly efficient and oxygen-tolerant polymerization with an extremely low catalyst loading (50 ppb). This system demonstrated a broad applicability to various monomers, achieving successful polymerization of methacrylates, acrylates, and styrene. Additionally, efficient photo-ATRP on a large scale (250 mL) was achieved, resulting in narrow molecular weight polymers with high monomer conversions and high chain-end fidelity. This work provides an in-depth investigation into the regulatory process of photo-ATRP, offering new insights into the intricate mechanism of oxygen tolerance.