An isoreticular metal-organic framework (MOF) series was constructed from nickel or cobalt nodes, phosphonate monoester, and bipyridine linkers. The cobalt-containing MOFs were found to catalyze the dehydrogenative C-H borylation of alkenes under mild conditions. This process selectively generates vinyl boronate without the formation of alkyl boronate byproducts and is insensitive to air, enabling large-scale preparation of the target products with isolated yields of over 80%.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
The direct catalytic carboxylation of benzylic tertiary C-H bonds with CO for the synthesis of all-carbon quaternary carboxylic acids represents a significant challenge. Here, we present a redox-neutral approach to address this difficulty by leveraging the synergistic interplay between photocatalysis and cascade hydrogen abstraction cycles. Remarkably, this strategy eliminates the need for sacrificial electron donors, electron acceptors, or stoichiometric additives, offering enhanced atom economy and environmental sustainability.
View Article and Find Full Text PDFSmall nucleolar RNAs (snoRNAs) are non-coding RNAs known for guiding RNA modifications, including 2'-O-methylation (N) and pseudouridine (Ψ). While snoRNAs may also interact with other RNAs, such as mRNA, the full repertoire of RNAs targeted by snoRNA remains elusive due to the lack of effective technologies that identify snoRNA targets transcriptome wide. Here, we develop a chemical crosslinking-based approach that comprehensively detects cellular RNA targets of snoRNAs, yielding thousands of previously unrecognized snoRNA-mRNA interactions in human cells and mouse brain tissues.
View Article and Find Full Text PDFEthnopharmacological Relevance: Dan'e fukang decoction (DFD) is a traditional Chinese medicine formula. DFD obtains 10 herbs, including Salvia yunnanensis C.H.
View Article and Find Full Text PDFIncreased circulating histones correlate with sepsis severity and are a potential therapeutic target. Pre-clinical studies showed benefit with a histone-neutralizing polyanion molecule (STC3141). We aimed to investigate the safety, tolerability, and pharmacokinetics of STC3141 in critically ill patients with sepsis.
View Article and Find Full Text PDFBackground: Respiratory syncytial virus (RSV) is a leading cause of severe illness in infants, with no effective treatment. Results of a phase 2 trial suggested that ziresovir may have efficacy in the treatment of infants hospitalized with RSV infection.
Methods: In a phase 3, multicenter, double-blind, randomized, placebo-controlled trial conducted in China, we enrolled participants 1 to 24 months of age who were hospitalized with RSV infection.
Two dual fluorescent/phosphorescent tris-heteroleptic mononuclear Ru(ΙΙ) complexes ( and ) were designed and applied in amyloid-β (Aβ) sensing. These complexes have a general formula of [Ru(phen)(dppz)()](PF), where is (2-pyrazinyl)(2-pyridyl)(methyl)amine (H-) with different substituents (-OMe for , -H for ), phen is 1,10-phenanthroline, and dppz is dipyridophenazine, respectively. Compared with the previously reported ratiometric probe with a di(pyrid-2-yl)(methyl)amine ligand, complex can be employed for not only ratiometric emissive detection of Aβ aggregation but also ratiometric imaging detection of Aβ fibrils.
View Article and Find Full Text PDFIt is urgent to develop an efficient and stable non-noble metal catalyst for selective C-H bond oxidation of cyclohexane. Herein, a series of V-W oxides supported on TiO catalysts (V-W/TiO) were fabricated. The V-W/TiO catalysts exhibited much higher catalytic activity for the selective oxidation of cyclohexane to KA oil, compared to that of V/TiO and W/TiO catalysts.
View Article and Find Full Text PDFIridium-catalyzed C-H borylation of aromatic and aliphatic hydrocarbons assisted by a directing group was theoretically investigated. Density functional theory (DFT) calculations revealed both Ir-catalyzed C(sp)-H and C(sp)-H borylations via an Ir/Ir catalytic cycle, where the tetra-coordinated (C, N)Ir(Bpin) complex with two vacant sites is an active species. Dramatically, the orientation of cyclometalation for C(sp)-H bond activation assisted by a directing group is different from the C(sp)-H one.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2024
Aqueous zinc-ion batteries are considered potential large-scale energy storage systems due to their low cost, environmentally friendly nature, and high safety. However, the development of high energy density cathode materials and uncertain reaction mechanisms remains a major challenge. In this work, the reaction mechanism, discharge voltage and diffusion properties of layered CrO as a cathode material for aqueous zinc-ion batteries were studied using first-principles calculations, and the effect of pre-intercalated structural water on the electrochemical performance of CrO electrodes is also discussed.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
The control of enantioselectivity in radical cation reactions presents long-standing challenges, despite a few successful examples. We introduce a novel strategy of asymmetric counteranion-directed electrocatalysis to address enantioselectivity in radical cation chemistry. This concept has been successfully demonstrated in two reactions: an asymmetric dehydrogenative indole-phenol [3+2] coupling and an atroposelective C-H/N-H dehydrogenative coupling.
View Article and Find Full Text PDFRadical C-H functionalization represents a useful means of streamlining synthetic routes by avoiding substrate preactivation and allowing access to target molecules in fewer steps. The first-row transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) are Earth-abundant and can be employed to regulate radical C-H functionalization. The use of such metals is desirable because of the diverse interaction modes between first-row transition metal complexes and radical species including radical addition to the metal center, radical addition to the ligand of metal complexes, radical substitution of the metal complexes, single-electron transfer between radicals and metal complexes, hydrogen atom transfer between radicals and metal complexes, and noncovalent interaction between the radicals and metal complexes.
View Article and Find Full Text PDFThe purpose of this work is to explore the properties of the lignin-derived amine-free photoinitiating systems (PISs) during the curing process. Four novel hydrogen donors (HD1, HD2, HD3, and HD4) derived from lignin α-O-4 structural were designed and synthesized by simple methods, and their low C-H bond dissociation energies on methylene were determined by molecular orbitals theory. Four experimental groups using CQ (camphorquinone)/HD PIs formulated with Bis-GMA/TEGDMA (70 w%/30 w%) were compared to CQ/EDB (ethyl 4-dimethylamino benzoate) system.
View Article and Find Full Text PDFGridization is an emerging molecular integration technology that enables the creation of multifunctional organic semiconductors through precise linkages. While Friedel-Crafts gridization of fluorenols is potent, direct linkage among fluorene molecules poses a challenge. Herein, we report an achiral Pd-PPh-cataylized diastereoselective (>99:1 d.
View Article and Find Full Text PDFPhotocatalysis holds a pivotal position in modern organic synthesis, capable of inducing novel reactivities under mild and environmentally friendly reaction conditions. However, the merger of photocatalysis and transition-metal-catalyzed asymmetric C-H activation as an efficient and sustainable method for the construction of chiral molecules remains elusive and challenging. Herein, we develop a cobalt-catalyzed enantioselective C-H activation reaction enabled by visible-light photoredox catalysis, providing a synergistic catalytic strategy for the asymmetric dearomatization of indoles with high levels of enantioselectivity (96 % to >99 % ee).
View Article and Find Full Text PDFThis study reports a protocol for the highly regioselective photocatalyzed C-H nitrosylation of imidazo[1,2-]pyridine scaffolds at the C3 position under a combination of visible-light irradiation and continuous flow without any external photocatalyst. This protocol involves mild and safe conditions and shows good tolerance to air and water along with excellent functional group compatibility and site selectivity, generating various 3-nitrosoimidazo[1,2-]pyridines in excellent yields under photocatalyst-, oxidant-, and additive-free conditions.Notably, the proposed nitrosylation reaction, which introduces the chromophore NO into imidazo[1,2-]pyridine scaffolds, occurs efficiently under visible-light irradiation without any additional photocatalyst owing to the intense light-absorption characteristics of the nitrosylation products.
View Article and Find Full Text PDFThe biogenic synthesis of silver nanoparticles (AgNPs) by microorganisms has been a subject of increasing attention. Despite extensive studies on this biosynthetic pathway, the mechanisms underlying the involvement of proteins and enzymes in AgNPs production have not been fully explored. Herein, we reported that Burkholderia contaminans ZCC was able to reduce Ag to AgNPs with a diameter of (10±5) nm inside the cell.
View Article and Find Full Text PDFWe report here a chromium-catalyzed intramolecular arylation of unactivated C-H bonds with C-halide bonds under mild conditions. This reaction was enabled by using a low-cost CrCl salt as the precatalyst in combination with allylmagnesium bromide and /-mixed 1-halo-2-styrylarenes as substates, providing a strategy for the construction of functionalized phenanthrene compounds without using external ligands.
View Article and Find Full Text PDFThe N-methyladenosine (mA) RNA modification is an important regulator of gene expression. mA is deposited by a methyltransferase complex that includes methyltransferase-like 3 (METTL3) and methyltransferase-like 14 (METTL14). High levels of METTL3/METTL14 drive the growth of many types of adult cancer, and METTL3/METTL14 inhibitors are emerging as new anticancer agents.
View Article and Find Full Text PDFElectrochemical C-H mono/multi-bromination regulation of -sulfonylanilines on the cost-effective CF electrode is described. This reaction proceeds smoothly under mild conditions with a broad substrate scope, affording diverse mono/multi-brominated anilines in moderate to good yields. Mechanism study reveals that this transformation involves anodic oxidation, aromatic electrophilic substitution, and deprotonation.
View Article and Find Full Text PDFAn efficient method for remote radical C(sp)-H azidation at unactivated sites is described. C-H functionalization proceeds via intramolecular 1,5-hydrogen atom transfer to N-centered radicals that are generated via azido group transfer and/or fragmentation. The readily installed sulfamoyl azide serves as both an amidyl radical precursor and an azido source.
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