Three-Component Synthesis of Isoquinolone Derivatives via Rh(III)-Catalyzed C-H Activation and Tandem Annulation.

A one-pot three-component synthesis of multifunctionalized isoquinolones from 2-oxazolines, iodonium ylides, and carboxylic acids via Rh(III)-catalyzed oxazolinyl-directed C-H activation and tandem annulation under redox-neutral conditions has been developed. This catalytic system is characterized by readily available starting materials, a wide tolerance of functional groups, a short reaction time, and high yields. The synthetic utility of the cascade reaction was further demonstrated by a gram-scale synthesis and derivatization of the obtained products.

Rhodium(III)-catalyzed oxidative annulation of isoquinolones with allyl alcohols: synthesis of isoindolo[2,1-b]isoquinolin-5(7H)-ones.

An efficient rhodium(III)-catalyzed direct C-H oxidative annulation of isoquinolones with allyl alcohols as C1 synthons has been successfully developed. This protocol enables the straightforward synthesis of structurally diverse isoindolo[2,1-b]isoquinolin-5(7H)-ones with high atom economy, tolerates a broad spectrum of functionalities, and is applicable to one-pot operation from readily available N-methoxybenzamides.

Synthesis of Cyclic Fragrances via Transformations of Alkenes, Alkynes and Enynes: Strategies and Recent Progress.

With increasing demand for customized commodities and the greater insight and understanding of olfaction, the synthesis of fragrances with diverse structures and odor characters has become a core task. Recent progress in organic synthesis and catalysis enables the rapid construction of carbocycles and heterocycles from readily available unsaturated molecular building blocks, with increased selectivity, atom economy, sustainability and product diversity. In this review, synthetic methods for creating cyclic fragrances, including both natural and synthetic ones, will be discussed, with a focus on the key transformations of alkenes, alkynes, dienes and enynes. Several strategies will be discussed, including cycloaddition, catalytic cyclization, ring-closing metathesis, intramolecular addition, and rearrangement reactions. Representative examples and the featured olfactory investigations will be highlighted, along with some perspectives on future developments in this area.

Correction: Rhodium(iii)-catalyzed oxidative alkylation of N-aryl-7-azaindoles with cyclopropanols.

Correction for 'Rhodium(iii)-catalyzed oxidative alkylation of N-aryl-7-azaindoles with cyclopropanols' by Jidan Liu et al., Org. Biomol. Chem., 2021, DOI: .

Rhodium(III)-catalyzed oxidative alkylation of N-aryl-7-azaindoles with cyclopropanols.

An efficient Rh(iii)-catalyzed C-H oxidative alkylation of N-aryl-7-azaindoles with cyclopropanols by merging tandem C-H and C-C cleavage was developed. This transformation features mild reaction conditions, high regioselectivity, and excellent functional group compatibility. The resulting ß-aryl ketone derivatives can be readily transformed into 7-azaindole-containing π-extended polycyclic heteroarenes.

Enantioselective Organocatalytic Desymmetrization of Cyclopentene-1,3-diones through Formal C(sp2)-H Amidation.

An enantioselective organocatalytic desymmetrization of 2,2-disubstituted cyclopentene-1,3-diones via a formal C(sp2)-H amidation is reported. The reaction was carried out with N-methoxy amide as the nitrogen source and commercially available cinchonidine as the catalyst under mild reaction conditions, releasing methanol as the only byproduct. It provides an efficient way to synthesize enantioenriched chiral cyclopentenyl amines bearing an all-carbon quaternary stereogenic carbon center.

Synthesis of Multisubstituted 1-Naphthoic Acids via Ru-Catalyzed C-H Activation and Double-Alkyne Annulation under Air.

An efficient [2 + 2 + 2] benzannulation of phthalic acids/anhydrides with two alkynes was developed for synthesis of multisubstituted 1-naphthoic acids via Ru-catalyzed C-H activation. The reaction preceded well using atmospheric oxygen as the sole oxidant with high atom/step economies. Facilitated by the free carboxyl group, the products can be easily converted to diverse polycyclic molecules.

C-H Activation and Alkyne Annulation via Automatic or Intrinsic Directing Groups: Towards High Step Economy.

Direct transformation of carbon-hydrogen bond (C-H) has emerged to be a trend for construction of molecules from building blocks with no or less prefunctionalization, leading high atom and step economy. Directing group (DG) strategy is widely used to achieve higher reactivity and selectivity, but additional steps are usually needed for installation and/or cleavage of DGs, limiting step economy of the overall transformation. To meet this challenge, we proposed a concept of automatic DG (DGauto ), which is auto-installed and/or auto-cleavable. Multifunctional oxime and hydrazone DGauto were designed for C-H activation and alkyne annulation to furnish diverse nitrogen-containing heterocycles. Imidazole was employed as an intrinsic DG (DGin ) to synthesize ring-fused and π-extended functional molecules. The alkyne group in the substrates can also be served as DGin for ortho-C-H activation to afford carbocycles. In this account, we intend to give a review of our progress in this area and brief introduction of other related advances on C-H functionalization using DGauto or DGin strategies.

Metal-free synthesis of imidazo[1,5-a]pyridines via elemental sulfur mediated sequential dual oxidative Csp3-H amination.

A simple and efficient approach has been developed for the synthesis of imidazo[1,5-a]pyridines using the elemental sulfur mediated sequential dual oxidative Csp3-H amination of 2-pyridyl acetates and amines under metal- and peroxide-free conditions. Broad substrate scope, operational simplicity and gram-scale ability make this chemistry very practical.

Synthesis of Natural Product-like Polyheterocycles via One-Pot Cascade Oximation, C-H Activation, and Alkyne Annulation.

An efficient protocol for the direct transformation of chroman-4-ones to tricyclic fused pyridines with the skeleton of cassiarins, a family of alkaloids with antimalarial activity, was developed. Also, a general strategy for modular construction of polyheterocycles with diverse natural product-like skeletons was developed by using ketone-alkyne bifunctional substrates. These reactions involved a one-pot cascade oximation of ketones, rhodium-catalyzed C-H activation, and intermolecular/intramolecular alkyne annulations under mild conditions with high atom, step, and redox economy.

Synthesis of Benzofulvene Derivatives from Diarylacetylenes via Pd(II)-Catalyzed Alkyne-Directed C(sp(2))-H Bond Activation.

A novel and efficient protocol for the synthesis of benzofulvene derivatives from easily available diarylacetylenes has been developed. The reaction proceeds through rarely reported carboxylate-assisted alkyne-directed ortho-C(sp(2))-H palladation followed by insertion of another diarylacetylene.

Rhodium(III)-catalyzed C-H activation and indole synthesis with hydrazone as an auto-formed and auto-cleavable directing group.

An efficient, practical, and external-oxidant-free indole synthesis from readily available aryl hydrazines was developed, by using hydrazone as a directing group for Rh(III)-catalyzed C-H activation and alkyne annulation. The hydrazone group was formed by in situ condensation of hydrazines and C=O source, whereas its N-N bond was served as an internal oxidant, for which we termed it as an auto-formed and auto-cleavable directing group (DG(auto)). This method needs no step for pre-installation and post-cleavage of the directing group, making it a quite easily scalable approach to access unprotected indoles with high step economy. The DG(auto) strategy was also applicable for isoquinoline synthesis. In addition, synthetic utilities of this chemistry for rapid assembly of π-extended nitrogen-doped polyheterocycles and bioactive molecules were demonstrated.

Modular assembly of ring-fused and π-extended phenanthroimidazoles via C-H activation and alkyne annulation.

π-Extension of 2-aryl-phenanthroimidazoles via rhodium(III)-catalyzed C-H activation and alkyne annulation is developed. This method enables rapid, practical and modular assembly of diverse ring-fused phenanthroimidazoles, including an unusual rearrangement product using aryl-alkyl asymmetric alkyne and a thiophene fused product which could serve as a Fe(3+) fluorescent probe. The feasibility of the one-pot synthesis and ruthenium(II)-catalyzed versions of this reaction was also verified.

Synthesis of chrysene derivatives via copper-catalyzed one-pot dimerization of 2-alkynyl-1-acetylbenzenes.

An efficient route for highly substituted chrysene derivatives via operationally simple copper-catalyzed one-pot dimerization of 2-alkynyl-1-acetylbenzenes is described.

One-pot synthesis of multisubstituted 2-aminoquinolines from annulation of 1-aryl tetrazoles with internal alkynes via double C-H activation and denitrogenation.

An efficient, one-pot synthesis of multisubstituted 2-aminoquinolines from 1-aryl tetrazoles and internal alkynes has been developed. The reaction involves cyclization of 1-aryl tetrazoles with internal alkynes via rhodium(III)-catalyzed double C-H activation and copper(II)-mediated denitrogenation.

Epilepsy Treatment and Diagnosis Enhanced by Current Nanomaterial Innovations: A Comprehensive Review.

Epilepsy is a complex disease in the brain. Complete control of seizure has always been a challenge in epilepsy treatment. Currently, clinical management primarily involves pharmacological and surgical interventions, with the former being the preferred approach. However, antiepileptic drugs often exhibit low bioavailability due to inherent limitations such as poor water solubility and difficulty penetrating the blood-brain barrier (BBB). These issues significantly reduce the drugs' effectiveness and limit their clinical application in epilepsy treatment. Additionally, the diagnostic accuracy of current imaging techniques and electroencephalography (EEG) for epilepsy is suboptimal, often failing to precisely localize epileptogenic tissues. Accurate diagnosis is critical for the surgical management of epilepsy. Thus, there is a pressing need to enhance both the therapeutic outcomes of epilepsy medications and the diagnostic precision of the condition. In recent years, the advancement of nanotechnology in the biomedical sector has led to the development of nanomaterials as drug carriers. These materials are designed to improve drug bioavailability and targeting by leveraging their large specific surface area, facile surface modification, ability to cross the BBB, and high biocompatibility. Furthermore, nanomaterials have been utilized as contrast agents in imaging and as materials for EEG electrodes, enhancing the accuracy of epilepsy diagnoses. This review provides a comprehensive examination of current research on nanomaterials in the treatment and diagnosis of epilepsy, offering new strategies and directions for future investigation.

Targeting Cellular Senescence in Aging and Age-Related Diseases: Challenges, Considerations, and the Emerging Role of Senolytic and Senomorphic Therapies.

Cellular senescence is characterized by the permanent arrest of cell proliferation and is a response to endogenous and exogenous stress. The continuous accumulation of senescent cells (SnCs) in the body leads to the development of aging and age-related diseases (such as neurodegenerative diseases, cancer, metabolic diseases, cardiovascular diseases, and osteoarthritis). In the face of the growing challenge of aging and age-related diseases, several compounds have received widespread attention for their potential to target SnCs. As a result, senolytics (compounds that selectively eliminate SnCs) and senomorphics (compounds that alter intercellular communication and modulate the behavior of SnCs) have become hot research topics in the field of anti-aging. In addition, strategies such as combination therapies and immune-based approaches have also made significant progress in the field of anti-aging therapy. In this article, we discuss the latest research on anti-aging targeting SnCs and gain a deeper understanding of the mechanism of action and impact of different anti-aging strategies on aging and age-related diseases, with the aim of providing more effective references and therapeutic ideas for clinical anti-aging treatment in the face of the ever-grave challenges of aging and age-related diseases.

Construction of cationic meso-thiazolium-BODIPY AIE fluorescent probes for viscosity imaging in dual organelles.

Two new cationic meso-thiazolium-BODIPY-based water-soluble and red-shifted fluorescent probes were constructed for the first time. They can monitor cellular viscosity in dual organelles and show aggregation-induced emission (AIE), which is ascribed to the efficient restricted rotation of meso-thiazolium in viscous or hindered systems. Probe 3 with an N-benzyl group shows better AIE as compared to probe 2 with an N-methyl group.

Synthesis of isoquinolines and heterocycle-fused pyridines via three-component cascade reaction of aryl ketones, hydroxylamine, and alkynes.

An efficient one-pot synthesis of isoquinolines and heterocycle-fused pyridines by three-component reaction of aryl ketones, hydroxylamine, and alkynes is developed. The reaction involves condensation of aryl ketones and hydroxylamine, rhodium(III)-catalyzed C-H bond activation of the in situ generated aryl ketone oximes, and cyclization with internal alkynes. This protocol enables rapid assembly of multisubstituted isoquinolines as well as γ-carbolines, furo[2,3-c]pyridines, thieno[2,3-c]pyridines, and benzofuro[2,3-c]pyridines from readily available substrates.

Novel cationic meso-CF3 BODIPY-based AIE fluorescent rotors for imaging viscosity in mitochondria.

Two novel meso-CF3 BODIPY-based fluorescent rotors have been rationally prepared and found to sensitively respond to viscosity in living cells with a fluorescence "turn-on" effect, attributed to the special restricted rotation of meso-CF3 group in viscous environments. Interestingly, a monostyryl probe with one cationic group exhibits good mitochondrial localization and AIE property.