Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 166
Filter
Add more filters










Publication year range
1.
Chem Sci ; 15(10): 3610-3615, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38455024

ABSTRACT

We report herein the synthesis of highly enantiopure inherently chiral N3,O-calix[2]arene[2]triazines from enantioselective macrocyclization enabled by chiral phosphoric acid-catalyzed intramolecular nucleophilic aromatic substitution reaction. In contrast to documented examples, the inherent chirality of the acquired compounds arises from one heteroatom difference in the linking positions of heteracalix[4](het)arenes.

2.
Scand Cardiovasc J ; 57(1): 2286885, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38010775

ABSTRACT

Objectives. Studies have shown that fasting blood glucose (FBG) is closely associated with poor prognosis in patients with coronary heart disease (CHD) after percutaneous coronary intervention (PCI), but its association with in-stent restenosis (ISR) is still unclear. Therefore, this study was to explore the association between FBG with ISR in patients with CHD after PCI. Design. In this cohort study, we included 531 patients with CHD who underwent PCI. Logistic regression, receiver operating characteristic (ROC), subgroup analysis and restricted cubic spline (RCS) were used to assess the association between FBG with ISR. Results. A total of 124 (23.4%) patients had ISR. Patients with higher levels of FBG had higher incidence of ISR compared to those with lower levels of FBG (p = 0.002). In multivariable logistic regression analyses, higher levels of FBG remained strongly associated with higher risk of ISR (as a categorical variable, OR: 1.89, 95% CI: 1.21-2.94, p = 0.005; as a continuous variable, OR: 1.12, 95% CI: 1.03-1.23, p = 0.011). ROC analysis also showed that FBG might be associated with the occurrence of ISR (AUC = 0.577, 95% CI: 0.52-0.64, p = 0.013). Subgroup analyses showed the association of FBG with ISR was also stable in several subgroups (< 60 years or ≥ 60 years, male, with or without smoking, without diabetes and without hypertension). And RCS analysis showed that FBG was linearly and positively associated with the risk of ISR. Conclusions. Higher levels of FBG were closely associated with higher risk of ISR in patients with CHD after PCI.


Subject(s)
Coronary Restenosis , Percutaneous Coronary Intervention , Humans , Male , Percutaneous Coronary Intervention/adverse effects , Cohort Studies , Blood Glucose , Coronary Restenosis/etiology , Constriction, Pathologic , Fasting , Coronary Angiography/adverse effects , Risk Factors , Retrospective Studies , Stents/adverse effects
3.
Support Care Cancer ; 31(10): 578, 2023 Sep 16.
Article in English | MEDLINE | ID: mdl-37715817

ABSTRACT

PURPOSE: Children with acute leukemia have suffered from a considerable symptom burden during chemotherapy. However, few studies have focused on exploring the mechanisms among symptoms in children with acute leukemia. Our study aims to explore core symptoms and describe the interrelationships among symptoms in children with acute leukemia during chemotherapy. METHODS: From January 2021 to March 2023, 469 children with acute leukemia were recruited from 20 Chinese cities. The Memorial Symptom Assessment Scale 10-18 (MSAS 10-18) was used to evaluate the prevalence and severity of symptoms during chemotherapy. A network analysis was performed by the R software based on 31 symptoms. Centrality indices and density were used to explore core symptoms and describe interrelationships among symptoms in the network during chemotherapy. RESULTS: Worrying and feeling irritable were the central symptoms across the three centrality indices, including strength, closeness, and betweenness. Lack of energy was the most prevalent symptom; however, it was less central than other symptoms. The density of the "induction and remission" network significantly differed from other cycles' counterparts (p < 0.001). Global strength was greater in the " ≥ 8 years group " network than the " < 8 years group " network (p = 0.023). CONCLUSION: Network analysis provides a novel approach to identifying the core symptoms and understanding the interrelationships among symptoms. Our study indicates the need to assess emotional symptoms in children with acute leukemia during chemotherapy, especially during the induction and remission phases, as well as in older children. Future research is imperative to construct trajectories of dynamic symptom networks and centrality indices in longitudinal data to investigate the causal relationships among symptoms.


Subject(s)
Antineoplastic Agents , Leukemia , Child , Humans , Asian People , Emotions , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/epidemiology , Software , Antineoplastic Agents/therapeutic use , Leukemia/diagnosis , Leukemia/drug therapy , Leukemia/psychology , Acute Disease , China
4.
Front Oncol ; 13: 1236129, 2023.
Article in English | MEDLINE | ID: mdl-37671049

ABSTRACT

Background: Previous studies have examined symptom clusters in children with acute leukemia, yet a knowledge gap persists regarding central symptom clusters and their influencing factors. By identifying these central clusters and associated factors, healthcare providers can enhance their understanding and effective management of symptoms. Our study seeks to address this gap by identifying symptom clusters, exploring central clusters, and investigating the demographic and health-related factors associated with these clusters in children with acute leukemia undergoing chemotherapy. Methods: A total of 586 children with acute leukemia from January 2021 to April 2023 were recruited from China. They were investigated using Memorial Symptom Assessment Scale 10-18 during chemotherapy. The principal component analysis was used to identify the symptom clusters. An association network was conducted to describe the relationships among symptoms and clusters. A multiple linear model was used to investigate the associated factors for the severity of overall symptoms and each symptom cluster. Results: Five clusters were identified, including oral and skin cluster, somatic cluster, self-image disorder cluster, gastrointestinal cluster and psychological cluster. Gastrointestinal cluster was the most central symptom cluster. Age, sex, clinical classification, number of having chemotherapy and education degree and marital status of the primary caregiver are associated with the severity of these five symptom clusters. Conclusion: Our study highlights the importance of evaluating symptom clusters in children with acute leukemia during chemotherapy. Specifically, addressing gastrointestinal symptoms is crucial for effective symptom management and overall care.

5.
Chem Sci ; 14(31): 8393-8400, 2023 Aug 09.
Article in English | MEDLINE | ID: mdl-37564407

ABSTRACT

In contrast to a plethora of macrocyclic and cage compounds, spirophanes have remained largely unexplored. We report herein the construction, structure and properties of unprecedented tetrahomo corona[4]arene-based ditopic and tritopic macrocycles of spiro structures. Synthesis was conveniently achieved by means of an efficient SNAr reaction from simple and commercially available starting materials. Racemic samples were resolved into enantiopure chiral tetrahomo i-corona[4]arenes, spirophanes and bispirophanes which show interesting chiroptical properties. The acquired electron-deficient macrocyclic compounds were found to adopt unique conformational structures and to form distinct complexes with TTF in the solid state. Our study provides a new opportunity to develop multitopic macrocycles of different topologies which have potential applications in supramolecular chemistry.

6.
Org Lett ; 25(27): 5105-5110, 2023 Jul 14.
Article in English | MEDLINE | ID: mdl-37383012

ABSTRACT

Despite their interesting stereochemistry and potential applications in (supramolecular) chemistry and chiroptical materials, inherently chiral macrocyclic compounds remain rare and are largely unexplored. We report herein a fragment coupling method to construct ABAC- and ABCD-type inherently chiral heteracalix[4]aromatics. The synthesis involves SNAr CuI-catalyzed Ullmann coupling and aliphatic nucleophilic substitution reactions as key steps using readily available starting materials. Postmacrocyclization functionalization reactions enabled the production of amino-substituted and (benzo[d])imidazole-2-(thi)one-bearing heteracalix[4]aromatics. Enantiopure ABCD-type macrocycles were obtained from resolution.


Subject(s)
Macrocyclic Compounds , Molecular Structure , Stereoisomerism , Calixarenes/chemistry
7.
Org Lett ; 25(21): 3936-3940, 2023 Jun 02.
Article in English | MEDLINE | ID: mdl-37219082

ABSTRACT

Asymmetric synthesis of enantioenriched zigzag-type molecular belts featuring copper/H8-binaphthol-catalyzed kinetic resolution of a resorcinarene derivative and subsequent transformations was developed. The acquired rigid and C4-symmetric belt exhibited remarkably enhanced photophysical and chiroptical properties in comparison to its conformationally fluxional macrocyclic precursor.

8.
Angew Chem Int Ed Engl ; 62(24): e202302646, 2023 Jun 12.
Article in English | MEDLINE | ID: mdl-37088714

ABSTRACT

Hydrocarbon belts have drawn great attention because of their unique structures and tantalizing properties. Although a few belts and heteroatom-doped analogs have been synthesized, belt molecules containing non-hexagonal rings remain rare. Herein we report the construction and application of unprecedented zigzag-type hydrocarbon belts which contain functionalized eight-membered rings. The synthesis features fourfold intramolecular acylation reactions of resorcin[4]arene-derived intermediates, which affords C4 -symmetric tetrabenzobelt[4]arene[4]cyclooctatrienones. Stereoselective ketone reduction with LiAlH4 and nucleophilic addition with alkynyllithiums provide the corresponding tetrahydroxylated belts. The tetraol and its methyl ether are powerful and selective hosts to form 2 : 1 and 1 : 1 complexes with cesium ion, respectively, with binding constants up to (1.71±0.33)×1011  M-2 and (1.50±0.16)×106  M-1 . In addition, enantiopure C4 -symmetric belts can emit CPL with |glum | being around 0.01.

9.
Chem Sci ; 14(4): 827-832, 2023 Jan 25.
Article in English | MEDLINE | ID: mdl-36755707

ABSTRACT

Under the catalysis of PdBr2 and a chiral phosphoramidite ligand, the upper-rim mono (2-bromoaroyl)-substituted calix[4]arene derivatives underwent a facile enantioselective desymmetrization reaction to afford 9H-fluorene-embedded inherently chiral calixarenes in good yields with excellent enantioselectivities. The transannular dehydrogenative arene-arene coupling reaction proceeded most probably through an oxidative addition of the Caryl-Br bond to a ligated palladium catalyst followed by a sequence of an enantioselective 1,5-palladium migration and an intramolecular C-H arylation sequence. This new family of inherently chiral calixarenes possesses unique chiroptical properties thanks to their highly rigid structure induced by the 9H-fluorene segment.

10.
Angew Chem Int Ed Engl ; 62(15): e202301782, 2023 Apr 03.
Article in English | MEDLINE | ID: mdl-36808689

ABSTRACT

Herein we report a two-directional cyclization strategy for the synthesis of highly strained depth-expanded oxygen-doped chiral molecular belts of the zigzag-type. From the easily accessible resorcin[4]arenes, an unprecedented cyclization cascade generating fused 2,3-dihydro-1H-phenalenes has been developed to access expanded molecular belts. Stitching up the fjords through intramolecular nucleophilic aromatic substitution and ring-closing olefin metathesis reactions furnished a highly strained O-doped C2 -symmetric belt. The enantiomers of the acquired compounds exhibited excellent chiroptical properties. The calculated parallelly aligned electric (µ) and magnetic (m) transition dipole moments are translated to the high dissymmetry factor (|glum | up to 0.022). This study provides not only an appealing and useful strategy for the synthesis of strained molecular belts but also a new paradigm for the fabrication of belt-derived chiroptical materials with high CPL activities.

11.
Org Lett ; 24(39): 7107-7112, 2022 Oct 07.
Article in English | MEDLINE | ID: mdl-36148969

ABSTRACT

A diversity of unprecedented chiral aza-crown ethers were synthesized straightforwardly from readily available and inexpensive aza-crown ethers. Catalyzed by a chiral phosphoric acid, desymmetrization of an array of symmetric N-arylated aza-crown ethers through tert-amino reaction proceeded efficiently under mild conditions to produce novel tetrahydroquinoline-fused aza-crown ethers in good to excellent yields with up to 96% ee. Our strategy opens a new route to functionalized chiral crown ethers.

12.
Acc Chem Res ; 55(19): 2796-2810, 2022 10 04.
Article in English | MEDLINE | ID: mdl-35994690

ABSTRACT

Recent decades have witnessed a resurgence of the study of copper-catalyzed organic reactions. As the surrogate of noble metal catalysts, copper salts have been shown to exhibit remarkable versatility in activating various C-H bonds enabling the construction of diverse carbon-carbon and carbon-heteroatom bonds. Advantageously, copper salts are also naturally abundant, inexpensive, and less toxic in comparison to precious metals. Despite significant developments in synthesis, the mechanism of copper catalysis remains elusive. Hypothetical pathways such as the two-electron Cu(III)/Cu(I) and Cu(II)/Cu(0) catalytic cycles and the one-electron Cu(II)/Cu(I) catalytic cycle have been invoked to diagram C-H bond transformations because of the formidable challenges to isolate and characterize transient high valent organocopper intermediates. In fact, organocopper chemistry has been dominated for a long time by the acknowledged nucleophilic organocopper(I) compounds. Since the beginning of the new millennium, we have been systematically studying the supramolecular chemistry of heteracalix[n]aromatics. Owing to the ease of their synthesis and selective functionalizations, self-tunable conformation and cavity structures resulting from the interplay of heteroatoms with aromatic subunits, and outstanding properties in molecular recognition and self-assembly, heteracalix[n]aromatics have become a class of privileged synthetic macrocyclic hosts. Our journey to the chemistry of high valent organocopper compounds started with a serendipitous discovery of the facile formation of a stable organocopper compound, which contains astonishingly a Ph-Cu(III) σ-bond under very mild aerobic conditions. When we examined routinely the effect of the macrocyclic structures on noncovalent complexation properties, titration of tetraazacalix[1]arene[3]pyridine with Cu(ClO4)2·6H2O resulted in the precipitation of dark-purple crystals of phenylcopper(III) diperchlorate. Our curiosity about the transformation of an arene C-H bond into an Ar-Cu(III) bond prompted us to conduct an in-depth investigation of the reaction of macrocyclic arenes with copper(II) salts, leading to the isolation of arylcopper(II) compounds which are unprecedented and the missing link in organocopper chemistry. With structurally well-defined organometallics in hand, we have explored extensively the reactivities of both arylcopper(II) and arylcopper(III) compounds, demonstrating their versatility and uniqueness in chemical synthesis. Novel and fascinating arene C-H transformations under copper catalysis have been developed. Using acquired high valent arylcopper compounds as molecular probes, and employing the functionalizations of tetraazacalix[1]arene[3]pyridines as model reactions, we have revealed the diverse mechanisms of copper-promoted arene C-H bond reactions. Elusive reaction pathways of some copper-catalyzed C-X bond activations have also been unraveled. In the meantime, we have also witnessed pleasingly the rapid development of field with the advent of new high valent organocopper compounds. Without any doubt, studies of the synthesis, reactivity, and catalysis of high valent organocopper compounds have been reshaping the field of organocopper chemistry. This Account summarizes our endeavors to explore the chemistry of structurally well-defined arylcopper(II) and arylcopper(III) compounds and the mechanisms of copper-catalyzed arene C-H and C-X bond transformations. We hope this Account will inspire chemists to study thoroughly the fundamentals and the cutting-edge catalysis of high valent organocopper compounds advancing and redefining the discipline of organocopper chemistry.


Subject(s)
Copper , Organocopper Compounds , Carbon , Catalysis , Copper/chemistry , Molecular Probes , Pyridines/chemistry , Salts
13.
World J Clin Cases ; 10(12): 3872-3878, 2022 Apr 26.
Article in English | MEDLINE | ID: mdl-35647151

ABSTRACT

BACKGROUND: In patients who suffer from both atrial fibrillation (AF) and atrial septal defect (ASD), cryoballoon pulmonary vein isolation (PVI), sequential left atrial appendage (LAA) occlusion and ASD closure could be a strategy for effective prevention of stroke and right heart failure. CASE SUMMARY: A 65-year-old man was admitted to our institution due to recurrent episodes of palpitations and shortness of breath for 2 years, which had been worsening over the last 48 h. He had a history of AF, ASD, coronary heart disease with stent implantation and diabetes. Physical and laboratory examinations showed no abnormalities. The score of CHA2DS2VASc was 3, and HAS-BLED was 1. Echocardiography revealed a 25-mm secundum ASD. Pulmonary vein (PV) and LAA anatomy were assessed by cardiac computed tomography. PV mapping with 10-pole Lasso catheter was performed following ablation of all four PVs with complete PVI. Following the cryoballoon PVI, the patient underwent LAA occlusion under transesophageal echocardiographic monitoring. Lastly, a 34-mm JIYI ASD occlude device was implanted. A follow-up transesophageal echocardiography at 3 mo showed proper position of both devices and neither thrombi nor leakage was found. CONCLUSION: Sequential cryoballoon PVI and LAA occlusion prior to ASD closure can be performed safely in AF patients with ASD.

14.
Org Lett ; 23(18): 7259-7263, 2021 Sep 17.
Article in English | MEDLINE | ID: mdl-34472872

ABSTRACT

Despite their unique structures, tantalizing properties, and potential applications in carbon nanoscience and technology, the synthesis and functionalization of zigzag hydrocarbon nanobelts have remained largely unexplored until recently. Reported herein is the selective transformations of belt[4]arene[4]tropilidenes and their application in the construction of novel belts. The oxidation of belt[4]arene[4]tropilidene with benzeneseleninic anhydride under controlled conditions selectively afforded mono- to tetrakis(α-diketone)-functionalized belt intermediates. A subsequent condensation reaction with 1,2-phenylenediacetonitrile and 1,2-phenylenediamine produced a diversity of unprecedented belts with various macrocyclic cavities.

15.
Nat Chem ; 13(5): 402-419, 2021 05.
Article in English | MEDLINE | ID: mdl-33859393

ABSTRACT

Aromatic hydrocarbon belts (AHCBs) have fascinated scientists for over half a century because of their aesthetically appealing structures and potential applications in the field of carbon nanotechnology. One of the enduring challenges in synthesizing AHCBs is how do we cope with the build-up of energy in the highly strained structures during their synthesis? Successful preparations of AHCBs offer the prospect of providing well-defined templates for the growth of uniform single-walled carbon nanotubes-a long-standing interest in nanocarbon science. In this Review, we revisit the protracted historical background involving the rational design and synthesis of AHCBs and highlight some of the more recent breakthroughs, with emphasis being placed on the different strategies that have been used for building up curved and fused benzenoid rings into molecular belts. We also discuss the scientific challenges in this fledgling field and provide some pointers as to what could transpire in years to come.

16.
Org Lett ; 23(5): 1835-1839, 2021 Mar 05.
Article in English | MEDLINE | ID: mdl-33576640

ABSTRACT

Starting from readily available tetratriflated resorcin[4]arene derivatives, C4-symmetric 1,3,5,7(1,3)-tetrabenzenacyclooctaphane tetraamines were synthesized conveniently by means of Pd-catalyzed C-N bond coupling reaction with diphenylmethanimine followed by hydrolysis. Subsequent Sandmeyer reaction and sulfonylation reaction efficiently afforded the corresponding tetraazide and tetrasulfonamide products, respectively. Upon treatment with PhI(OAc)2, tetrasulfonamides underwent facile oxidative transannular cyclization reaction to produce mono- and dispiro macrocyclic compounds selectively rather than N4-octahydrobelt[8]arenes. Conformational structures of resulting macrocycles are presented, and the reaction mechanism is discussed.

17.
PeerJ ; 9: e12686, 2021.
Article in English | MEDLINE | ID: mdl-35036160

ABSTRACT

BACKGROUND: At present, there is no effective treatment for myocardial fibrosis in atrial fibrillation (AF). It is reported that miR-15a-5p is abnormally expressed in AF patients but its specific role remains unclear. This study aims to investigate the effect of miR-15a-5p in myocardial fibrosis. METHODS: Left atrial appendage (LAA) tissues were collected from AF and non-AF patients. In lipopolysaccharide (LPS) stimulated H9C2 cells, miR-15a-5p mimic, inhibitor, pcDNA3.1-Smad7 and small interfering RNA-Smad7 (siRNA-Smad7) were respectively transfected to up-regulate or down-regulate the intracellular expression levels of miR-15a-5p and Smad7. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) were used to determine the expression levels of miR-15a-5p, Smad7, transforming growth factor ß1 (TGF-ß1) and collagen I. Cell counting kit-8 (CCK-8) and ethylene deoxyuridine (EdU) were used to determine cell viability and proliferation capacity, respectively. Dual-luciferase was used to detect whether miR-15a-5p interacted with Smad7, hydroxyproline (HYP) and Hematoxylin-Eosin (HE) staining were used to detect tissue fibrosis. RESULTS: The expression levels of miR-15a-5p, TGF-ß1 and collagen I were up-regulated, while Smad7 was down-regulated in AF tissues and LPS-stimulated cells. MiR-15a-5p mimic can inhibit the expression of Smad7, and the dual-luciferase experiment confirmed their interaction. MiR-15a-5p inhibitor or pcDNA3.1-Smad7 can inhibit LPS-induced fibrosis and cell proliferation, while siRNA-Smad7 can reverse the changes caused by miR-15a-5p inhibitor. CONCLUSION: We combined clinical studies with LPS-stimulated H9C2 cell model to validate the role of miR-15a-5p in the regulation of Smad7 and fibrosis. Taken together, the miR-15a-5p/Smad7 pathway might be a potential target for AF therapy.

18.
J Org Chem ; 85(20): 13211-13219, 2020 10 16.
Article in English | MEDLINE | ID: mdl-33026225

ABSTRACT

We report herein an efficient cascade strategy for the rapid construction of a highly enantioenriched erythrinane core skeleton. Under the sequential catalysis of a chiral Cr(III)(salen)Cl and InCl3, cyclohexanone-derived tertiary enamides undergo an intramolecular enantioselective nucleophilic addition followed by diastereoselective Pictet-Spengler cyclization. This method is highly enantio- and diastereoselective, leading to diverse erythrina alkaloid derivatives as the sole diastereoisomer with up to 98% ee.

19.
Angew Chem Int Ed Engl ; 59(52): 23649-23658, 2020 Dec 21.
Article in English | MEDLINE | ID: mdl-33047450

ABSTRACT

Despite the aesthetically appealing structures and tantalizing physical and chemical properties, zigzag hydrocarbon belts and their heteroatom-embedded analogues remain challenging synthetic targets. We report herein the synthesis of diverse O/N-doped zigzag hydrocarbon belts based on selective bridging of the fjords of resorcin[4]arene derivatives through intramolecular SN Ar and palladium-catalyzed intermolecular C-N bond formation reactions. Preorganized conformations of mono-macrocyclic, half-belt and quasi-belt compounds were revealed to facilitate cyclization reactions to construct heteroatom-linked octahydrobelt[8]arenes. The acquired products had strained square-prism-shaped belt structures in which all six-membered heterocyclic rings adopted an unusual boat conformation with equatorially configured alkyl groups. The unprecedented heteroatom-bearing belts also exhibited different photophysical and redox properties to those of octahydrobelt[8]arene analogues.

20.
Angew Chem Int Ed Engl ; 59(52): 23716-23723, 2020 12 21.
Article in English | MEDLINE | ID: mdl-32910541

ABSTRACT

i-Corona[3]arene[3]tetrazines were synthesized from the nucleophilic aromatic substitution reaction of resorcinol and its derivatives with 3,6-dichlorotetrazine in a one-pot fashion under mild conditions. All of the resulting macrocycles adopted 1,3,5-alternate conformation irrespective of the nature of the substituents on both upper- and lower-rims. i-Corona[3]arene[3]tetrazine was found to self-regulate its macrocyclic conformation and cavity to recognize anions with binding constants spanning from 26 M-1 to 2.2×103  M-1 depending on the structure of the anions. The selective binding resulted from a significant interdependent and synergistic effect between multiple tetrazine π/anion and Caryl -H/anion hydrogen bond interactions. Taking advantage of synergistic effect revealed, a cyanobenzene-embedded i-corona[3]arene[3]tetrazine was designedly synthesized and highly selective and very strong affinity toward nitrate with a binding constant of 2.2×105  M-1 was achieved.

SELECTION OF CITATIONS
SEARCH DETAIL
...