Decoupled peak property learning for efficient and interpretable electronic circular dichroism spectrum prediction.

Electronic circular dichroism (ECD) spectra contain key information about molecular chirality by discriminating the absolute configurations of chiral molecules, which is crucial in asymmetric organic synthesis and the drug industry. However, existing predictive approaches lack the consideration of ECD spectra owing to the data scarcity and the limited interpretability to achieve trustworthy prediction. Here we establish a large-scale dataset for chiral molecular ECD spectra and propose ECDFormer for accurate and interpretable ECD spectrum prediction.

Full on-device manipulation of olefin metathesis for precise manufacturing.

Olefin metathesis, as a powerful metal-catalysed carbon-carbon bond-forming method, has achieved considerable progress in recent years. However, the complexity originating from multicomponent interactions has long impeded a complete mechanistic understanding of olefin metathesis, which hampers further optimization of the reaction. Here, we clarify both productive and hidden degenerate pathways of ring-closing metathesis by focusing on one individual catalyst, using a sensitive single-molecule electrical detection platform.

Infrared Spectra Prediction for Functional Group Region Utilizing a Machine Learning Approach with Structural Neighboring Mechanism.

Infrared (IR) spectroscopy is a pivotal technique in chemical research for elucidating molecular structures and dynamics through vibrational and rotational transitions. However, the intricate molecular fingerprints characterized by unique vibrational and rotational patterns present substantial analytical challenges. Here, we present a machine learning approach employing a structural neighboring mechanism tailored to enhance the prediction and interpretation of infrared spectra.

Multifunctional injectable microspheres for osteoarthritis therapy via spatiotemporally modulating macrophage polarization and inflammation.

Local injection of anti-inflammatory drugs for osteoarthritis emerged as a promising administration in the clinic, and sustained-release dosage forms have great potential for future therapeutic applications. Controlling the response of patients only in the acute inflammatory phase is currently the focus of therapeutic interventions. To relieve acute pain in patients and to improve the long-term prognosis effect of osteoarthritis treatment, we designed a two-pronged approach in this research: an injectable double-layer microsphere containing a "nonsteroidal anti-inflammatory drug - macrophage polarizing factor" was constructed.

Visible-Light-Induced Transition-Metal-Free Redox-Neutral Carboxylation of Remote Benzylic C(sp)-H Bonds via 1,5-Hydrogen Atom Transfer.

The direct carboxylation of the benzylic C-H bonds under mild conditions is of great importance and is quite challenging. Herein, we report an approach for the carboxylation of remote benzylic C(sp)-H bonds by integrating the redox-neutral visible-light photoredox catalysis and the nitrogen-centered 1,5-hydrogen atom transfer. The chemical transformation progresses via consecutive single electron transfer, 1,5-hydrogen atom transfer, formation of benzylic carbanion, and nucleophilic attack on the CO steps, thereby enabling access to the desired carboxylation products with moderate to high yields.

Transition metal-free visible light photoredox-catalyzed remote C(sp)-H borylation enabled by 1,5-hydrogen atom transfer.

The borylation of unreactive carbon-hydrogen bonds is a valuable method for transforming feedstock chemicals into versatile building blocks. Here, we describe a transition metal-free method for the photoredox-catalyzed borylation of unactivated C(sp)-H bond, initiated by 1,5-hydrogen atom transfer (HAT). The remote borylation was directed by 1,5-HAT of the amidyl radical, which was generated by photocatalytic reduction of hydroxamic acid derivatives.

Retention time prediction for chromatographic enantioseparation by quantile geometry-enhanced graph neural network.

The enantioseparation of chiral molecules is a crucial and challenging task in the field of experimental chemistry, often requiring extensive trial and error with different experimental settings. To overcome this challenge, here we show a research framework that employs machine learning techniques to predict retention times of enantiomers and facilitate chromatographic enantioseparation. A documentary dataset of chiral molecular retention times in high-performance liquid chromatography (CMRT dataset) is established to handle the challenge of data acquisition.

Direct Stannylation and Silylation of Arylmethanols by Palladium Catalysis.

A direct transformation of non-preactivated benzyl alcohols to benzyl stannanes and benzyl silanes was realized through Pd-catalyzed C(sp)-O activation process. By using versatile tin and silicon sources, these reactions exhibit a broad substrate scope and a high efficiency under mild conditions, affording functionalized benzyl and allylic stannanes and benzylsilanes with high yields. The successful implementation of gram-scale stannylation/silylation as well as the one-pot Stille coupling reaction demonstrates the potential application of this method in organic synthesis.

High-throughput automated platform for thin layer chromatography analysis.

In this protocol, we detail steps for constructing a high-throughput automated platform for thin layer chromatography (TLC) analysis. We describe robotics and computer vision techniques that can handle 32 compounds under three different elution solvents in about 50 min. The established automated platform can obtain statistically standardized retardation factor (R) values and enhance reproducibility while reducing labor and time costs.

Precise electrical gating of the single-molecule Mizoroki-Heck reaction.

Precise tuning of chemical reactions with predictable and controllable manners, an ultimate goal chemists desire to achieve, is valuable in the scientific community. This tunability is necessary to understand and regulate chemical transformations at both macroscopic and single-molecule levels to meet demands in potential application scenarios. Herein, we realise accurate tuning of a single-molecule Mizoroki-Heck reaction via applying gate voltages as well as complete deciphering of its detailed intrinsic mechanism by employing an in-situ electrical single-molecule detection, which possesses the capability of single-event tracking.

Combination of oxaliplatin and POM-1 by nanoliposomes to reprogram the tumor immune microenvironment.

Some chemotherapy can damage tumor cells, releasing damage-related molecular patterns including ATP to improve immunological recognition against the tumor by immunogenic cell death (ICD). However, the immune-stimulating ATP may be rapidly degraded into immunosuppressive adenosine by highly expressed CD39 and CD73 in the tumor microenvironment, which leads to immune escape. Based on the above paradox, a liposome nanoplatform combined with ICD inducer (oxaliplatin) and CD39 inhibitor (POM-1) is designed for immunochemotherapy.

Transition Metal Free Stannylation of Alkyl Halides: The Rapid Synthesis of Alkyltrimethylstannanes.

A transition metal free stannylation reaction of alkyl bromides and iodides with hexamethyldistannane has been developed. This protocol is operationally convenient and features a rapid reaction and good functional group tolerance. A wide range of functionalized primary and secondary alkyl and benzyl trimethyl stannanes are prepared in moderate to excellent yields.

Accurate Single-Molecule Kinetic Isotope Effects.

An accurate single-molecule kinetic isotope effect (sm-KIE) was applied to circumvent the inherent limitation of conventional ensemble KIE by using graphene-molecule-graphene single-molecule junctions. monitoring of the single-molecule reaction trajectories in real time with high temporal resolution has the capability to characterize the deeper information brought by KIE. The C-O bond cleavage and the C-C bond formation of the transition state (TS) were observed in the Claisen rearrangement through the secondary kinetic isotope effect, demonstrating the high detection sensitivity and accuracy of this method.

Unveiling the full reaction path of the Suzuki-Miyaura cross-coupling in a single-molecule junction.

Conventional analytic techniques that measure ensemble averages and static disorder provide essential knowledge of the reaction mechanisms of organic and organometallic reactions. However, single-molecule junctions enable the in situ, label-free and non-destructive sensing of molecular reaction processes at the single-event level with an excellent temporal resolution. Here we deciphered the mechanism of Pd-catalysed Suzuki-Miyaura coupling by means of a high-resolution single-molecule platform.

Anodic oxidation triggered divergent 1,2- and 1,4-group transfer reactions of β-hydroxycarboxylic acids enabled by electrochemical regulation.

We report a set of electrochemically regulated protocols for the divergent synthesis of ketones and β-keto esters from the same β-hydroxycarboxylic acid starting materials. Enabled by electrochemical control, the anodic oxidation of carboxylic acids proceeded in either a one-electron or a two-electron pathway, leading to a 1,4-aryl transfer or a semipinacol-type 1,2-group transfer product with excellent chemoselectivity. The 1,4-aryl transfer represents an unprecedented example of carbon-to-oxygen group transfer proceeding a radical mechanism.

Transition metal- and light-free radical borylation of alkyl bromides and iodides using silane.

We report operationally simple and neutral conditions for borylation of alkyl bromides and iodides to alkyl boronic esters under transition metal- and light-free conditions. A series of substrates with a wide range of functional groups were effectively transformed into the borylation products in moderate to good yields. Mechanistic studies, including radical clock experiments and DFT calculations, gave detailed insight into the radical borylation process.

Recent Development of Aryl Diazonium Chemistry for the Derivatization of Aromatic Compounds.

Aryl diazonium salts are versatile building blocks in organic synthesis. In light of the ever-increasing importance of aryl diazonium salts spanning most disciplines of the chemical sciences, we review the recent development of aryl diazonium chemistry over the past seven years (2013-2020). Special emphasis is put on various new transformations involving the generation of radical intermediates via thermal, photochemical, and electrochemical means.

An accurate, high-speed, portable bifunctional electrical detector for COVID-19.

Unlabelled: Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has rapidly spread and caused a severe global pandemic. Because no specific drugs are available for COVID-19 and few vaccines are available for SARS-CoV-2, accurate and rapid diagnosis of COVID-19 has been the most crucial measure to control this pandemic. Here, we developed a portable bifunctional electrical detector based on graphene fieldeffect transistors for SARS-CoV-2 through either nucleic acid hybridization or antigen-antibody protein interaction, with ultra-low limits of detection of ~0.

Electrocatalytic Oxidative Transformation of Organic Acids for Carbon-Heteroatom and Sulfur-Heteroatom Bond Formation.

The electrolysis of organic acids has garnered increasing attention in recent years. In addition to the famous electrochemical decarboxylation known as Kolbe electrolysis, a number of other electrochemical processes have been recently established that allow for the construction of carbon-heteroatom and sulfur-heteroatom bonds from organic acids. Herein, recent advances in electrochemical C-X and S-X (X=N, O, S, Se) bond-forming reactions from five classes of organic acids and their conjugate bases, namely, carboxylic, thiocarboxylic, phosphonic, sulfinic, and sulfonic acids, are surveyed.

Modification of TiO Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti Complex.

As one of the most promising semiconductor oxide materials, titanium dioxide (TiO) absorbs UV light but not visible light. To address this limitation, the introduction of Ti defects represents a common strategy to render TiO visible-light responsive. Unfortunately, current hurdles in Ti generation technologies impeded the widespread application of Ti modified materials.

Zn-O Dual-Spin Surface State Formation by Modification of ZnO Nanoparticles with Diboron Compounds.

ZnO semiconductor oxides are versatile functional materials that are used in photoelectronics, catalysis, sensing, etc. The Zn-O surface electronic states of semiconductor oxides were formed on the ZnO surface by Zn 4s and O 2p orbital coupling with the diboron compound's B 2p orbitals. The formation of spin-coupled surface states was based on the spin-orbit interaction on the interface, which has not been reported before.

Transition-Metal-Free Borylation of Alkyl Iodides via a Radical Mechanism.

We describe an operationally simple transition-metal-free borylation of alkyl iodides. This method uses commercially available diboron reagents as the boron source and exhibits excellent functional group compatibility. Furthermore, a diverse range of primary and secondary alkyl iodides could be effectively transformed to the corresponding alkylboronates in excellent yield.

Mn-Mediated Electrochemical Trifluoromethylation/C(sp)-H Functionalization Cascade for the Synthesis of Azaheterocycles.

A general electrohemical strategy for the combined trifluoromethylation/C(sp)-H functionalization using Langlois' reagent as the CF source under oxidant-free conditions was developed. Using Mn salts as the redox mediator, this method provides an efficient and sustainable means to access a variety of functionalized heterocycles bearing a CF moiety. Detailed mechanistic studies are consistent with the formation of CF-bound high oxidation state Mn species, suggesting a transition-metal-mediated CF transfer mechanism for this trifluoromethylation/C(sp)-H functionalization process.

A general electrochemical strategy for the Sandmeyer reaction.

Herein we report a general electrochemical strategy for the Sandmeyer reaction. Using electricity as the driving force, this protocol employs a simple and inexpensive halogen source, such as NBS, CBrCl, CHI, CCl, LiCl and NaBr for the halogenation of aryl diazonium salts. In addition, we found that these electrochemical reactions could be performed using anilines as the starting material in a one-pot fashion.

C-H Bond Carboxylation with Carbon Dioxide.

Carbon dioxide is a nontoxic, renewable, and abundant C source, whereas C-H bond functionalization represents one of the most important approaches to the construction of carbon-carbon bonds and carbon-heteroatom bonds in an atom- and step-economical manner. Combining the chemical transformation of CO with C-H bond functionalization is of great importance in the synthesis of carboxylic acids and their derivatives. The contents of this Review are organized according to the type of C-H bond involved in carboxylation.