Solvent-Controlled Divergent Cyclization of 3-Ylideneoxindoles with Ethyl 2-Diazoacetate: Access to Spirocyclopropyl and Spiropyrazolines Oxindoles.

Herein a catalyst-free solvent-controlled method for the divergent synthesis of spirocyclopropyl and spiropyrazoline oxindoles from 3-ylideneoxindoles and ethyl diazoacetate was developed. With ClCH2CH2Cl as the solvent, spirocyclopropyl oxindoles were obtained in moderate to excellent yields, whereas the use of MeOH as solvent afforded spiropyrazoline oxindoles in moderate to good yields. The readily available substrates, simple operation and various product transformations further highlighted the utility of this method.

Base-Mediated Allylic Defluorinative Functionalizations of ß-CF2H-1,3-enynes Enables the Construction of Terminal Monofluoroenynes.

The base-mediated allylic defluorinative functionalization of ß-CF2H-1,3-enynes with nucleophiles is described, affording terminal monofluoroalkenes bearing an alkynyl group in synthetically useful yields and Z/E selectivities. Importantly, the resultant Z/E mixture could be separated by flash chromatography in all cases; thus, stereoisomerically pure monofluoroenynes were obtained. Postsynthetic modifications of the synthesized monofluoroenynes were also accomplished to access diverse molecular structures. Computational studies disclosed the origin of the diastereoselectivity.

Synthesis of Benzopyrone-Fused Hydrobenzo[c,d]indoles via Cascade Annulation of p-Quinamines and 3-Formylchromones.

A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed cascade annulation reaction between p-quinamines and 3-formylchromones was developed, affording a series of benzopyrone-fused hydrobenzo[c,d]indoles in moderate to high yields with excellent diastereoselectivity. This cascade reaction is efficient since two new rings as well as one C-N, one C═C, and two C-C bonds are created in a single step. The scale-up synthesis and versatile transformations of the products further demonstrated the practicality and utility of this approach.

Triglyceride-glucose index as a potential predictor of major adverse cardiovascular and cerebrovascular events in patients with coronary heart disease complicated with depression.

Background: Triglyceride-glucose (TyG) index is a surrogate marker of insulin resistance and metabolic abnormalities, which is closely related to the prognosis of a variety of diseases. Patients with both CHD and depression have a higher risk of major adverse cardiovascular and cerebrovascular events (MACCE) and worse outcome. TyG index may be able to predict the adverse prognosis of this special population. Methods: The retrospective cohort study involved 596 patients with both CHD and depression between June 2013 and December 2023. The primary outcome endpoint was the occurrence of MACCE, including all-cause death, stroke, MI and emergent coronary revascularization. The receiver operating characteristic (ROC) curve, Cox regression analysis, Kaplan-Meier survival analysis, and restricted cubic spline (RCS) analysis were used to assess the correlation between TyG index and MACCE risk of in patients with CHD complicated with depression. Results: With a median follow-up of 31 (15-62) months, MACCE occurred in 281(47.15%) patients. The area under the ROC curve of TyG index predicting the risk of MACCE was 0.765(0.726-0.804) (P<0.01). Patients in the high TyG index group(69.73%) had a significantly higher risk of developing MACCE than those in the low TyG index group(23.63%) (P<0.01). The multifactorial RCS model showed a nonlinear correlation (nonlinear P<0.01, overall P<0.01), with a critical value of 8.80 for the TyG index to predict the occurrence of MACCE. The TyG index was able to further improve the predictive accuracy of MACCE. Conclusions: TyG index is a potential predictor of the risk of MACCE in patients with CHD complicated with depression.

Base-Controlled Divergent Synthesis of Fluorine-Containing Benzo[4,5]imidazo[2,1-b][1,3]thiazines from 2-Mercaptobenzimidazoles and ß-CF3-1,3-Enynes.

A base-controlled divergent cyclization between 2-mercaptobenzimidazoles and ß-CF3-1,3-enynes providing either trifluoromethylated or fluorinated benzo[4,5]imidazo[2,1-b][1,3]thiazines has been developed. The ß-CF3-1,3-enyne, as a three-carbon synthon, underwent a 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU)-catalyzed tandem hydroamination/intramolecular hydrothiolation to give CF3-substituted 3,4-dihydro-2H-benzo[4,5]imidazo[2,1-b][1,3]thiazine, whereas reaction with KOH afforded fluorinated 4H-benzo[4,5]imidazo[2,1-b][1,3]thiazine exclusively. In addition, the synthetic utility of this methodology was showcased through a variety of downstream derivatizations.

Synthesis of CF3-Substituted Alkylamines, 1,2-Bisazoles, and 1,4,5,6-Tetrahydro-1,2,4-triazines from Newly Designed Tetrazole-Activated Trifluoromethyl Alkenes.

A new class of Michael acceptor, tetrazolyl-trifluoromethyl alkenes, has been discovered. They readily undergo Michael-type addition instead of addition-elimination reaction with aliphatic amines and azoles to furnish ß-trifluoromethyl alkylamines and CF3-substituted 1,2-bisazole derivatives, respectively. Additionally, some of the products are capable of engaging in microwave-assisted intramolecular denitrogenative annulation, leading to the formation of CF3-substituted 1,4,5,6-tetrahydro-1,2,4-triazines that are otherwise difficult to access by other methodologies.

N-Trifluoropropylation of Azoles through N-Vinylation and Sequential Hydrogenation.

Installing a fluoroalkyl group onto the nitrogen atom of azoles represents a potential strategy for lead optimization in medicinal chemistry. Herein, we describe a method for the N-trifluoropropylation of azoles. This process is accomplished using a combination of regioselective N-vinylation and sequential hydrogenation. The two-step sequence is applicable to a diverse set of azoles and tolerates a wide range of functionalities. In addition, we showcase its practicability and utility through the gram-scale synthesis and the late-stage modification of a complex molecule.

Catalytic divergent synthesis of imidazoles via reaction condition-dependent [3 + 2] cyclization of TosMIC.

A base-catalyzed divergent synthesis of multisubstituted imidazoles through TosMIC-based [3 + 2] cyclization reaction has been developed. In the presence of ketenimines and tBuONa, 1,4,5-trisubstituted imidazoles were obtained. Nonetheless, in the absence of ketenimines, 1,4-disubstituted imidazole was produced through cyclodimerization of TosMIC.

Antidiarrheal effect of ethanol extract from Lophatheri Herba and its effect on isolated jejunal smooth muscle in rabbits.

Lophatheri Herba is a traditional Chinese medicine, which is commonly used in the treatment of fever, stomatitis, urodynia. The aim of the study is to evaluate the antidiarrheal activity of the ethanol extract of Lophatheri Herba (Gramineae, ELH) and observe its effect on isolated jejunum smooth muscle in rabbits, so that we can provide a possible pharmacological basis for its clinical use. Methods: In vivo, the antidiarrheal activity of ELH (250, 500 and 1000 mg/kg; orally) in castor oil-induced Kun Ming mice was evaluated. In vitro, the effect of ELH (0.01-10 mg/mL) on the spontaneous and ACh (10µM)/K+ (60mM)-induced contraction of isolated rabbit jejunum smooth muscle was studied. The possible mechanism of spasmolytic effect of ELH (1, 3mg/mL) was explored by pretreatment of intestinal tract with CaCl2. Results: ELH (500 and 1000mg/kg) exhibited antidiarrheal effect and it (0.01-10 mg/mL) inhibited the spontaneous and ACh/K+-induced contraction with an EC50 value of 1.27 (0.89-1.34), 0.76 (0.54-1.02) and 0.34 (0.27-0.53), it also shifted the concentration-response curves of CaCl2 to right with decreased in max, similar to verapamil. ELH has significant antidiarrheal and spasmolytic effect, this provides the pharmacological basis for use in gastrointestinal disorders.

Ursolic acid inhibits Th17 cell differentiation via STAT3/RORγt pathway and suppresses Schwann cell-mediated Th17 cell migration by reducing CXCL9/10 expression.

Th17 cells represent important immune cells. Ursolic acid (UA) can regulate immune cell activities. This study was aimed to explore the effects of UA on Th17 cell differentiation and Schwann cell(SCs)-mediated migration and the potential mechanism. Naïve CD4+ T cells were isolated from rat peripheral blood, induced for Th17 cell differentiation, and treated with UA. The proportion of Th17 cells was detected by flow cytometry assay. SCs were co-cultured with Th17 cells. Th17 cell migration was detected by Transwell assay. The molecule expression was determined by Western blot and qRT-PCR. UA inhibited the Th17 cell differentiation and suppressed the STAT3/RORγt pathway. STAT3 overexpression up-regulated p-STAT3 and RORγt expression and promoted Th17 cell differentiation under the UA treatment. In LPS- and IFN-γ-stimulated-SCs, UA suppressed the expression of chemokines CXCL9/10, but had no significant effect of CCL20 expression. The expression CXCL9/10 receptor CXCR3 was higher in Th17 cells than that in Treg cells, while the expression CCL20 receptor CCR6 was lower in Th17 cells than that in Treg cells. UA, anti-CXCR3, and anti-CCR6 treatment inhibited SCs-mediated Th17 cell migration, and anti-CXCR3 exerted stronger inhibitory effect than Anti-CCR6. UA inhibited Th17 cell differentiation through STAT3/RORγt pathway and suppressed Th17 cell migration through down-regulating CXCL9/10 expression in SCs.

Diversity-Oriented Synthesis of Fluoromethylated Arenes via Palladium-Catalyzed C-H Fluoromethylation of Aryl Iodides.

Herein we report the first versatile and expeditious method for the site-selective C-H fluoromethylation of aryl iodides via Pd/norbornene cooperative catalysis, which could work as a robust toolbox for the diversity-oriented synthesis (DOS) of fluoromethylated arenes. This methodology features the use of the low-cost industrial raw material CH2IF as the fluoromethyl source, an excellent functional group tolerance, and a broad ipso termination scope and can be expanded to the late-stage modification of biorelevant molecules.

1,2-Dicarbofunctionalization of Trifluoromethyl Alkenes with Pyridinium Salts via a Cycloaddition/Visible-Light-Enabled Fragmentation Cascade.

Although trifluoromethyl alkenes have great synthetic potential, their 1,2-difunctionalization has been a challenge. In this Letter, we disclose the first 1,2-dicarbofunctionalization of trifluoromethyl alkenes with pyridinium salts via a cascade process involving a base-promoted [3 + 2] cycloaddition followed by a visible-light-mediated Norrish-type-II fragmentation. This protocol allows for the formation of pyridines bearing a trifluoromethyl-substituted quaternary center in moderate to excellent yields under mild conditions.

Stereoselective Access to Spirooxindoles and Bisoxindoles Through Organocatalyzed Asymmetric Divergent Transformations of Isatin-derived MBH Carbonates.

An interesting ß-isoquinidine catalyzed divergent reaction was developed to produce either spirocyclopentene oxindoles, spirocyclopentadiene oxindoles or bisoxindoles in a high enantioselective fashion. The utility of this protocol was demonstrated by the versatile transformations of the products. This work not only represents the first highly stereoselective intermolecular catalytic asymmetric allylic alkylation reaction between two isatin-derived MBH carbonate molecules but also constitutes a rare example of isatin-derived MBH carbonate-based enantioselective and α-regioselective [3+2] cycloaddition reactions.

Catalytic Enantioselective Isocyanide-Based Reactions: Beyond Passerini and Ugi Multicomponent Reactions.

The development of catalytic enantioselective isocyanide-based reactions is currently of great interest because the resulting products are valuable in organic synthesis, pharmacological chemistry, and materials science. This review assembles and comprehensively summarizes the recent achievements in this rapidly growing area according to the reaction types. Special attention is paid to the advantages, limitations, possible mechanisms, and synthetic applications of each reaction. In addition, a personal outlook on the opportunities for further exploration is given at the end.

Catalytic enantioselective synthesis using carbon dioxide as a C1 synthon.

This review summarizes the advances in catalytic enantioselective reactions using CO2 as a C1 synthon, introduces major synthetic strategies and discusses their advantages and limitations, highlights the application of known protocols, and outlines the synthetic opportunities.

Reductive CO2 Fixation via the Selective Formation of C-C Bonds: Bridging Enaminones and Synthesis of 1,4-Dihydropyridines.

Herein, a selective tandem C-C bond-forming reaction with CO2 was developed to realize the bridging of enaminones and synthesis of 1,4-dihydropyridines, respectively. n-Butylamine significantly promoted this CO2 deoxymethylenation procedure catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and ZnCl2. The mechanism involving the formation of bis(silyl)acetal, nucleophilic addition, and amine elimination was also interpreted to clarify the bridging of two molecules of enaminones with CO2 and the generation of dihydropyridine derivatives.

Hydrosilane-Assisted Synthesis of Urea Derivatives from CO2 and Amines.

A methodology employing CO2, amines, and phenylsilane was discussed to access aryl- or alkyl-substituted urea derivatives. This procedure was characterized by adopting hydrosilane to promote the formation of ureas directly, without the need to prepare silylamines in advance. Control reactions suggested that FeCl3 was a favorable additive for the generation of ureas, and this 1,5,7-triazabicyclo[4.4.0]dec-5-ene-catalyzed reaction might proceed through nucleophilic addition, silicon migration, and the subsequent formal substitution of silylcarbamate.

Synthesis of fused-tetrahydropyrimidines: one-pot methylenation-cyclization utilizing two molecules of CO2.

A methylenation-cyclization reaction, employing cyclic enaminones with primary aromatic amines and two molecules of CO2, furnishing fused-tetrahydropyrimidines, is discussed. In this Cs2CO3 and ZnI2 catalyzed one-pot two-step procedure, two molecules of CO2 were selectively converted to methylene groups. The multi-component reaction might proceed through the formation of bis(silyl)acetal which was followed by condensation and further aza-Diels-Alder reaction. Hydroquinazoline, hydrocyclopenta[d]pyrimidine and hydroindeno[1,2-d]pyrimidine derivatives could be prepared with CO2 as the C1 source, effectively.

Diastereoselective Synthesis of 1,3-Diyne-Tethered Trifluoromethylcyclopropanes through a Sulfur Ylide Mediated Cyclopropanation/DBU-Mediated Epimerization Sequence.

A one-pot synthesis of 1,3-diyne-tethered trifluoromethylcyclopropanes starting from 2-CF3-3,5-diyne-1-enes and sulfur ylides via a sulfur ylide mediated cyclopropanation and a DBU-mediated epimerization sequence is described in this work. This process is highly diastereoselective with broad substrate scope. Moreover, a series of synthetic transformations based on the diyne moieties were conducted smoothly, affording cyclopropanes featuring trifluoromethyl-substituted all-carbon quaternary centers.

Paeoniflorin attenuates early brain injury through reducing oxidative stress and neuronal apoptosis after subarachnoid hemorrhage in rats.

Paeoniflorin is a natural monoterpene glucoside from Paeoniae Radix with neuroprotective properties. However, it is still unclear whether paeoniflorin has neuroprotective effects on subarachnoid hemorrhage (SAH). This study explores the effect of paeoniflorin on early brain injury (EBI) using rat SAH model. We found that paeoniflorin significantly improves neurological deficits, attenuates brain water content and Evans blue extravasation at 72 h after SAH. Paeoniflorin attenuates the oxidative stress following SAH as evidenced by decrease of reactive oxygen species (ROS), malondialdehyde (MDA), 3-Nitrotyrosine, and 8-Hydroxy-2-deoxy guanosine (8-OHDG) level, increase of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase activity, and up-regulates the nuclear factor erythroid­related factor 2 (Nrf2)/heme oxygenase­1 (HO-1) pathway. Inhibition of microglia activation and neuro-inflammatory response both contributed to paeoniflorin's protective effects. Moreover, paeoniflorin treatment significantly reduces the ratio of Bax/Bcl-2, active caspase-3/ neuronal nuclei (NeuN) and TUNEL/DAPI positive cells at 72 h following SAH. Our results indicate that paeoniflorin may attenuate early brain injury after experimental SAH.