Borirenes and Boriranes: Development and Perspectives.

Strained compounds constitute a highly topical area of research in chemistry. Borirene and borirane both feature a BC three-membered ring. They can be viewed as the structural analogues of cyclopropane and cyclopropene, where a CH unit of the carbonaceous counterparts is replaced with BH, respectively.

Enhancing Local CO Adsorption by L-histidine Incorporation for Selective Formate Production Over the Wide Potential Window.

Electrochemical carbon dioxide reduction reaction (CO RR) to produce valuable chemicals is a promising pathway to alleviate the energy crisis and global warming issues. However, simultaneously achieving high Faradaic efficiency (FE) and current densities of CO RR in a wide potential range remains as a huge challenge for practical implements. Herein, we demonstrate that incorporating bismuth-based (BH) catalysts with L-histidine, a common amino acid molecule of proteins, is an effective strategy to overcome the inherent trade-off between the activity and selectivity.

Gel transformation as a general strategy for fabrication of highly porous multiscale MOF architectures.

The structure and chemistry of metal-organic frameworks or MOFs dictate their properties and functionalities. However, their architecture and form are essential for facilitating the transport of molecules, the flow of electrons, the conduction of heat, the transmission of light, and the propagation of force, which are vital in many applications. This work explores the transformation of inorganic gels into MOFs as a general strategy to construct complex porous MOF architectures at nano, micro, and millimeter length scales.

Selective multifunctionalization of -heterocyclic carbene boranes the intermediacy of boron-centered radicals.

The selective difunctionalization of -heterocyclic carbene (NHC) boranes with alkenes has been achieved decatungstate and thiol synergistic catalysis. The catalytic system also allows stepwise trifunctionalization, leading to complex NHC boranes with three different functional groups which are challenging to prepare by other methods. The strong hydrogen-abstracting ability of the excited decatungstate enables the generation of boryl radicals from mono- and di-substituted boranes for realizing borane multifunctionalization.

BN-Butafulvenes and Their Application in the Synthesis of Highly Substituted BN-9,1-Naphthalenes.

BN-butafulvenes, mono-BN isosteres of butafulvene and highly strained isomers of azaborines and B-amino boroles, have been synthesized via hydrolysis of the urana-borabicyclic complexes obtained from the reactions of bis(alkynyl)boranes with an uranacyclopropene complex. Their 4-dimethylaminopyridine (DMAP) adducts can further isomerize to 1,2,4,6-multisubstituted BN-9,1-naphthalenes. Both NMR reaction monitoring and theoretical calculations point to a reaction mechanism involving dearomative insertion of DMAP followed by two consecutive 1,2-hydrogen shifts.

Type-I AIE Photosensitizer Loaded Biomimetic System Boosting Cuproptosis to Inhibit Breast Cancer Metastasis and Rechallenge.

Cuproptosis shows good application prospects in tumor therapy. However, the copper efflux mechanism and highly expressed intracellular reducing substances can inhibit the cuproptosis effects. In this study, a platelet vesicle (PV) coated cuprous oxide nanoparticle (CuO)/TBP-2 cuproptosis sensitization system (PTC) was constructed for multiple induction of tumor cuproptosis.

Multi-Domain versus Single-Domain: A Magnetic Field is Not a Must for Promoting Spin-Polarized Water Oxidation.

The reaction kinetics of spin-polarized oxygen evolution reaction (OER) can be enhanced by ferromagnetic (FM) catalysts under an external magnetic field. However, applying a magnetic field necessitates additional energy consumption and creates design difficulties for OER. Herein, we demonstrate that a single-domain FM catalyst without external magnetic fields exhibits a similar OER increment to its magnetized multi-domain one.

Persistent and Predominantly Localized Boron Radical from the Reduction of a Three-Dimensional Analogue of NHC-Stabilized Borafluorenium.

In this contribution, we reported the three-dimensional (3D) analogues of N-heterocyclic carbene (NHC)-stabilized 9-borafluorenium and 9-borafluorene radical. The radical was fully characterized by cyclic voltammetry (CV), UV-Vis absorption spectroscopy, electron paramagnetic resonance (EPR) and single-crystal X-ray diffraction analyses. The distinct boron-centered radical character of 9-borafluorene radical was corroborated by DFT calculations and EPR analysis.

Electrochemical oxidation of styrene to benzaldehyde by discrimination of spin-paired π electrons.

The oxidation of styrene to benzaldehyde has been a considerable challenge in the electrochemical synthesis of organic compounds because styrene is more easily oxidized to benzoic acid. In this work, MnO with an asymmetric electronic configuration is designed to discriminate the spin-paired π electrons of styrene. One of these discriminated π electrons combined with reactive oxygen species (ROS), ˙OH, ˙OOH, , produced simultaneously on a MnO/(RuTi)O/Ti bifunctional anode, to form benzaldehyde , rather than benzoic acid.

Rhodium(III)-Catalyzed C-H/O Dual Activation and Macrocyclization: Synthesis and Evaluation of Pyrido[2,1-a]isoindole Grafted Macrocyclic Inhibitors for Influenza H1N1.

The development of environment-friendly, step economic couplings to generate structurally diverse macrocyclic compounds is highly desirable but poses a marked challenge. Inspired by the C-H oxidation mechanism of cytochromes P450, an unprecedented and practical Rh -catalyzed acylmethylation macrocyclization via C-H/O dual activation has been developed by us. The process of macrocyclization is facilitated by a synergic coordination from pyridine and ester group.

Construction of multiphasic membraneless organelles towards spontaneous spatial segregation and directional flow of biochemical reactions.

Many intracellular membraneless organelles (MLOs) appear to adapt a hierarchical multicompartment organization for efficient coordination of highly complex reaction networks. Recapitulating such an internal architecture in biomimetic platforms is, therefore, an important step to facilitate the functional understanding of MLOs and to enable the design of advanced microreactors. Herein, we present a modular bottom-up approach for building synthetic multiphasic condensates using a set of engineered multivalent polymer-oligopeptide hybrids.

A type I AIE photosensitiser-loaded biomimetic nanosystem allowing precise depletion of cancer stem cells and prevention of cancer recurrence after radiotherapy.

Radioresistance of Cancer stem cell (CSC) is an important cause of tumor recurrence after radiotherapy (RT). Herein, we designed a type I aggregation-induced emission (AIE) photosensitiser-loaded biomimetic mesoporous organosilicon nanosystem (PMT) for precise depletion of CSC to prevent tumor recurrence after RT. This PMT system is composed of a type I AIE photosensitiser (TBP-2) loaded mesoporous organosilicon nanoparticles (MON) with an outer platelet membrane.

Understanding the Organometallic Step: SO Insertion into Bi(III)-C(Ph) Bond.

Heavier main-group element-catalyzed reactions provide an increasingly attractive tool to perform transformations mimicking the behaviors of transition metal catalysts. Recently, Magre and Cornella reported a Bi-catalyzed synthesis of aryl sulfonyl fluorides, which involves a fundamental organometallic step of SO insertion into the Bi-Ph bond. Our theoretical studies reveal that i) the ability of hypervalent coordination of the Bi(III) center allows facile coordination sphere expansion for the SO coordination via one oxygen atom; and ii) the high polarity of the Bi-Ph bond makes the Ph migration from the Bi(III) center feasible.

Synthesis and characterization of bi(metallacycloprop-1-ene) complexes.

In all previously reported metallacycloprop-1-ene or η-vinyl complexes, the metal center bears only one vinyl moiety. We have now successfully synthesized and structurally characterized the first complexes bearing two η-vinyl moieties or spiro bi(metallacycloprop-1-ene) complexes from reactions of alkynes with rhenium phosphine complexes. Computational studies indicate that the metallacycloprop-1-ene rings are aromatic and the complexes represent a rare σ-type spirometalla-aromatic system.

Backbone-controlled LUMO energy induces intramolecular C-H activation in -bis-9-borafluorene-substituted phenyl and -carboranyl compounds leading to novel 9,10-diboraanthracene derivatives.

The choice of backbone linker for two -bis-(9-borafluorene)s has a great influence on the LUMO located at the boron centers and, therefore, the reactivity of the respective compounds. Herein, we report the room temperature rearrangement of 1,2-bis-(9-borafluorenyl)--carborane, CBH-1,2-[B(CH)] ([2a]) featuring -carborane as the inorganic three-dimensional backbone and the synthesis of 1,2-bis-(9-borafluorenyl)benzene, CH-1,2-[B(CH)] (2b), its phenylene analog. DFT calculations on the transition state for the rearrangement support an intramolecular C-H bond activation process an SAr-like mechanism in [2a], and predicted that the same rearrangement would take place in 2b, but at elevated temperatures, which indeed proved to be the case.

Ten-step asymmetric total syntheses of potent antibiotics anthracimycin and anthracimycin B.

The increase in antibiotic resistance calls for the development of novel antibiotics with new molecular structures and new modes of action. However, in the past few decades only a few novel antibiotics have been discovered and progressed into clinically used drugs. The discovery of a potent anthracimycin antibiotic represents a major advance in the field of antibiotics.

Photoinduced Dehydrogenative Borylation via Dihydrogen Bond Bridged Electron Donor and Acceptor Complexes.

Air-stable amine- and phosphine-boranes are discovered as donors to integrate with pyridinium acceptor for generating photoactive electron-donor-acceptor (EDA) complexes. Experimental results and DFT calculations suggest a dihydrogen bond bridging the donor and acceptor. Irradiating the EDA complex enables an intra-complex single electron transfer to give a boron-centered radical for dehydrogenative borylation with no need of external photosensitizer and radical initiator.

Palladium-catalyzed intramolecular enantioselective C(sp)-H insertion of donor/donor carbenes.

Herein, the first palladium-catalyzed intramolecular enantioselective C(sp)-H insertion reaction of donor-donor carbenes has been successfully achieved. This facile protocol enables the rapid construction of a collection of enantioenriched decorated indolines with two contiguous stereocenters in a single step. Both enynones and diazo compounds are efficient donor-donor carbene precursors for this reaction.

Enhanced response of titanium doped iron(ii) oxalate under electric field.

Electrorheological (ER) fluid, containing polarized particles within an insulating liquid, represents a smart material, the mechanical properties of which can be altered mainly by an electric field. In this work, ER fluids based on cauliflower iron(ii) oxalate doped titanium particles show excellent rheological and wetting properties by the sample co-precipitation method. The morphology of the particles is observed by SEM and the molecular structure within the particles is obtained XRD and FTIR.

MnO doped graphene nanosheets for carotid body tumor combination therapy.

Combination therapy is a cornerstone of tumor therapy, which can make up for the shortcomings of a single treatment and improve the cure rate of cancer. Near infrared induced therapy is widely applied owing to good accessibility, safety profile, and a wide range of effectiveness. Here, we use reduced nanographene oxide (rNGO) sheets with MnO nanoparticles as a photothermal agent to trigger further photodynamic therapy and chemotherapy.

Boosting Ring Strain and Lewis Acidity of Borirane: Synthesis, Reactivity and Density Functional Theory Studies of an Uncoordinated Arylborirane Fused to o-Carborane.

Among the parent borirane, benzoborirene and ortho-dicarbadodecaborane-fused borirane, the latter possesses the highest ring strain and the highest Lewis acidity according to our density functional theory (DFT) studies. The synthesis of this class of compounds is thus considerably challenging. The existing examples require either a strong π-donating group or an extra ligand for B-coordination, which nevertheless suppresses or completely turns off the Lewis acidity.

Electrochemical oxidative rearrangement of tetrahydro-β-carbolines in a zero-gap flow cell.

Oxidative rearrangement of tetrahydro-β-carbolines (THβCs) is one of the most efficient methods for the synthesis of biologically active spirooxindoles, including natural products and drug molecules. Here, we report the first electrochemical approach to achieve this important organic transformation in a flow cell. The key to the high efficiency was the use of a multifunctional LiBr electrolyte, where the bromide (Br) ion acts as a mediator and catalyst and lithium ion (Li) acts as a likely hydrophilic spectator, which might considerably reduce diffusion of THβCs into the double layer and thus prevent possible nonselective electrode oxidation of indoles.

Neutral Boryl Radicals in Mixed-Valent B Br-B Adducts.

The general strategies to stabilize a boryl radical involve single electron delocalization by π-system and the steric hinderance from bulky groups. Herein, a new class of boryl radicals is reported, with intramolecular mixed-valent B Br-B adducts ligated by a cyclic (alkyl)(amino)carbene (CAAC). The radicals feature a large spin density on the boron center, which is ascertained by EPR spectroscopy and DFT calculations.

Improving stable isotope assessments of inter- and intra-species variation in coral reef fish trophic strategies.

Fish have one of the highest occurrences of individual specialization in trophic strategies among Eukaryotes. Yet, few studies characterize this variation during trophic niche analysis, limiting our understanding of aquatic food web dynamics. Stable isotope analysis (SIA) with advanced Bayesian statistics is one way to incorporate this individual trophic variation when quantifying niche size.

A review on recent advances in the electrochemical reduction of CO to CO with nano-electrocatalysts.

The electrochemical reduction (ECR) of CO is a powerful strategy to reduce the world's carbon footprint by converting CO to useful products such as CHOH and CO. Recent techno-economic analysis has found that for the electro-conversion of CO to be adapted for practical use, the main products formed from this reaction need to be low-order, such as CO. This review summarizes recent progress in the ECR of CO to CO on nano-electrocatalysts (noble, non-noble metals and carbon nanomaterials) and provides the limitations and challenges that each electrocatalyst faces.