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1.
J Asian Nat Prod Res ; : 1-7, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38676379

RESUMO

Many organic reactions rely on CO2 sources to generate important structural units and valuable chemicals. In this study, we compared the effects of cannabidiol (CBD) and cannabidiolic acid (CBDA) on the supercritical CO2 (scCO2)-induced de/carboxylation reaction. The results showed that CBD was directly carboxylated in the ortho-position to form CBDA with up to 62% conversion. Meanwhile, CBDA decarboxylation occurred on hemp plant material via varying composition. Mechanistic studies revealed that CBD carboxylation was influenced not only by the physical properties of scCO2, but also by the vegetable matrix.

2.
J Fluoresc ; 33(4): 1413-1419, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36719610

RESUMO

As one of the most toxic metals, Mercury ions cause serious environmental pollution and threaten the health of living organisms. Hence, we designed and synthesised a new near-infrared (NIR) ratiometric fluorescent probe toward monitoring of Hg2+ based on quinoline-fused rhodamine dye. Owing to the specific spirolactam ring-opening reaction, the probe exhibits a ratiometric fluorescent change after treatment of Hg2+ with increased emission in NIR and significantly reduced emission in visible region. The specific response mechanism and dual-channel fluorescence change allow the probe to have remarkable detection selectivity, fast response and high detection sensitivity. Moreover, with the properties of excellent cell permeability and low cytotoxicity, probe can be applied as detection tool for mercury ions with dual-channel ratiometric fluorescence imaging in living cell.


Assuntos
Corantes Fluorescentes , Mercúrio , Rodaminas , Microscopia de Fluorescência , Íons
3.
Macromol Rapid Commun ; 44(5): e2200755, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36433758

RESUMO

The facile and rapid fabrication of oriented porous polymers is crucial for flexible pressure sensors. Herein, a pressure sensor is developed based on oriented porous polydimethylsiloxane (PDMS) composites for detecting human motion and identifying joint motion patterns. The oriented porous PDMS composite is first constructed through thiol-ene click chemistry and directional freezing within only 30 min, then fabricated by interfacial in situ polymerization of dopamine and pyrrole to generate robust interfaces. As a result, the as-prepared oriented porous PDMS composite is assembled into a pressure sensor that shows potential applications in pressure and human motion detection. Interestingly, a sensor assembled by orthogonally stacking the PDMS composites can be used for joint motion pattern recognition with potential monitoring of football motion due to their directional structures. This facile strategy coupled with the oriented porous structure is expected to help design advanced wearable electronic devices.


Assuntos
Dispositivos Eletrônicos Vestíveis , Humanos , Porosidade , Movimento (Física) , Polímeros , Dimetilpolisiloxanos/química
4.
Molecules ; 28(19)2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37836635

RESUMO

Syndiotactic polystyrene (SPS) refers to a type of thermoplastic material with phenyl substituents that are alternately chirally attached on both sides of an aliphatic macromolecular main chain. Owing to its excellent physical and mechanical properties, as well as its chemical stability, high transparency, and electrical insulation characteristics, SPS is used in a wide variety of technical fields. SPS is commonly produced via the stereoselective transition metal-catalyzed coordination polymerization method mediated by stereospecific catalysts, which consists of anionic mono-cyclopentadienyl derivative η5-coordinated single active metal centers (referred to as "mono-Cp'-M"), with active center metals involving Group 4 transition metals (with an emphasis on titanium) and rare-earth (RE) metals of the periodic table. In this context, the use of mono-cyclopentadienyl titanocene (mono-Cp'Ti) catalysts and mono-cyclopentadienyl rare-earth metal (mono-Cp'RE) metallocene catalysts for the syndiospecific polymerization of styrene is discussed. The effects of the mono-cyclopentadienyl ligand structure, cationic active metal types, and cocatalysts on the activity and syndiospecificity of mono-Cp' metallocene catalysts are briefly surveyed.

5.
Org Biomol Chem ; 20(8): 1642-1646, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35108719

RESUMO

Catalytic construction of oxindoles bearing all-carbon-quaternary centers attracts wide attention from the synthetic chemistry community. Herein, we report a palladium-catalyzed sequential Heck coupling/C-C bond activation of aryl halide-tethered alkenes with benzocyclobutenols affording a series of oxindole-derived compounds in good to excellent yields, as well as the preliminary enantioselectivity results.

6.
J Gene Med ; 23(12): e3388, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34438465

RESUMO

BACKGROUND: Circular RNAs (circRNAs) are key regulators in the progression of various cancers. Abnormal DNA methylation patterns feature prominently in the regulation of the expression of tumor-related genes. This study is aimed at investigating the molecular mechanism of circ_0040809 affecting colorectal cancer (CRC) progression by regulating DNA methyltransferase 1 (DNMT1). METHODS: circ_0040809 was selected from the circRNA microarray datasets (GSE142837 and GSE138589). Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to examine the expression of circ_0040809, miR-515-5p, and DNMT1 mRNA in paired cancerous and paracancerous tissues of 40 CRC patients, as well as in cell lines. Western blotting was conducted for detecting DNMT1 protein expression in CRC cells. Cell proliferation, migration, and apoptosis were assessed through CCK-8, Transwell, and flow cytometry assays. Bioinformatics and dual-luciferase gene assay were conducted to predict and verify, respectively, the targeted relationships between circ_0040809 and miR-515-5p, as well as between miR-515-5p and DNMT1 mRNA. RESULTS: In CRC tissues and cells, circ_0040809 and DNMT1 expression are markedly increased, whereas miR-515-5p expression is decreased. Also, high circ_0040809 expression is significantly linked to shorter overall survival. Cell function compensation experiments reveal that circ_0040809 silencing inhibits CRC cell proliferation and migration and promotes apoptosis, while circ_0040809 overexpression has the opposite effects. Mechanistically, circ_0040809 competitively binds to miR-515-5p to elevate DNMT1 expression. Rescue assay reveals that overexpressed miR-515-5p partly counteracts the tumor-facilitating impact of circ_0040809. CONCLUSIONS: circ_0040809 facilitates CRC cell proliferation and migration, and inhibits apoptosis, through modulating miR-515-5p/DNMT1 axis. Our study implies that targeting circ_0040809 may be a therapy strategy for CRC treatment.


Assuntos
Neoplasias Colorretais , MicroRNAs , Proliferação de Células/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , Humanos , Metiltransferases , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Circular/genética , Regulação para Cima
7.
Proc Natl Acad Sci U S A ; 115(43): 11036-11041, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-30297433

RESUMO

Damage to intestinal epithelial cell (IEC) layers during intestinal inflammation is associated with inflammatory bowel disease. Here we show that the endoribonuclease Regnase-1 controls colon epithelial regeneration by regulating protein kinase mTOR (the mechanistic target of rapamycin kinase) and purine metabolism. During dextran sulfate sodium-induced intestinal epithelial injury and acute colitis, Regnase-1∆IEC mice, which lack Regnase-1 specifically in the intestinal epithelium, were resistant to body weight loss, maintained an intact intestinal barrier, and showed increased cell proliferation and decreased epithelial apoptosis. Chronic colitis and tumor progression were also attenuated in Regnase-1∆IEC mice. Regnase-1 predominantly regulates mTORC1 signaling. Metabolic analysis revealed that Regnase-1 participates in purine metabolism and energy metabolism during inflammation. Furthermore, increased expression of ectonucleotidases contributed to the resolution of acute inflammation in Regnase-1∆IEC mice. These findings provide evidence that Regnase-1 deficiency has beneficial effects on the prevention and/or blocking of intestinal inflammatory disorders.


Assuntos
Colo/metabolismo , Células Epiteliais/metabolismo , Mucosa Intestinal/metabolismo , Purinas/metabolismo , Regeneração/fisiologia , Ribonucleases/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Apoptose/fisiologia , Proliferação de Células/fisiologia , Colite/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Camundongos , Transdução de Sinais/fisiologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-38523537

RESUMO

BACKGROUND: Lung Adenocarcinoma (LUAD), a common and aggressive form of lung cancer, poses significant treatment challenges due to its low survival rates. AIM: To better understand the role of ferroptosis driver genes in LUAD, this study aimed to explore their diagnostic and prognostic significance, as well as their impact on treatment approaches and tumor immune function in LUAD. METHOD: To accomplish the defined goals, a comprehensive methodology incorporating both in silico and wet lab experiments was employed. A comprehensive analysis was conducted on a total of 233 ferroptosis driver genes obtained from the FerrDB database. Utilizing various TCGA databases and the RT-qPCR technique, the expression profiles of 233 genes were examined. Among them, TP53, KRAS, PTEN, and HRAS were identified as hub genes with significant differential expression. Notably, TP53, KRAS, and HRAS exhibited substantial up-regulation, while PTEN demonstrated significant down-regulation at both the mRNA and protein levels in LUAD samples. The dysregulation of hub genes was further associated with poor overall survival in LUAD patients. Additionally, targeted bisulfite-sequencing (bisulfite-seq) analysis revealed aberrant promoter methylation patterns linked to the dysregulation of hub genes. RESULT & DISCUSSION: Furthermore, hub genes were found to participate in diverse oncogenic pathways, highlighting their involvement in LUAD tumorigenesis. By leveraging the diagnostic and prognostic potential of ferroptosis driver hub genes (TP53, KRAS, PTEN, and HRAS), significant advancements can be made in the understanding and management of LUAD pathogenesis. CONCLUSION: Therapeutic targeting of these genes using specific drugs holds great promise for revolutionizing drug discovery and improving the overall survival of LUAD patients.

9.
Prev Med Rep ; 37: 102536, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38186662

RESUMO

Purpose: The aim of this study was to explore the relationship between non-alcoholic fatty liver disease (NAFLD) and the two blood inflammatory markers including the systemic immune-inflammation (SII) index, and the system inflammation response index (SIRI). Methods: The National Health and Nutrition Examination Survey data between the year of 2017-2018 was used for this cross-sectional study. In order to analyze the association of SII index, and SIRI and risk of NAFLD, we used multivariable logistic regression models, restricted cubic spline (RCS) plot, and subgroup analysis to analyze the data. Results: In total, there were 1,199 individuals who participated in the survey. As shown by the RCS plot, SII index, and SIRI were linked with NAFLD risk in a U-shaped pattern. With regard to known confounding variables, when comparing the lowest quartile, the odds ratio with 95 % confidence interval for prevalence of NAFLD across the quartiles of SII index and SIRI were (0.89 (0.57, 1.41), 0.56 (0.35, 0.89) and 1.01 (0.64, 1.59)), and (0.77 (0.48, 1.23), 0.79 (0.50, 1.24) and 0.94 (0.60, 1.47)), respectively. Additionally, SII index, and SIRI and NAFLD risk also were U-curve correlated among the participants in age ≥60 years, female, without hypertension, and BMI of ≥30 kg/m2. Conclusions: There was a U-shaped association of SII index and SIRI with prevalence of NAFLD, indicating that SII index and SIRI should be monitored dynamically.

10.
Front Oncol ; 14: 1274953, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38590655

RESUMO

Background: Angiomyolipoma with epithelial cysts (AMLEC) is an extremely rare subtype of kidney angiomyolipoma that contains epithelial-lined cysts. The most distinctive immunohistochemical feature of AMLEC is its immunoreactivity with melanocytic markers. AMLEC also has a distinct histological structure, which aids in its pathological diagnosis. To date 27 cases of AMLEC have been reported in 11 case series. However, the molecular biology underlying the pathogenesis of AMLEC remains unexplored. Case report: A 30-year-old female was diagnosed with AMLEC and underwent partial nephrectomy. Histologically, the cross-section of cystic tissue revealed a multilocular appearance, with some cysts containing thrombus-like material, and the wall thickness was approximately 0.2 ~ 0.3 cm. Additionally, the compact subepithelial cellular stroma showed strong and diffuse nuclear labeling for estrogen receptor, progesterone receptor, and CD10, as well as HMB45 and Melan A, which are markers of melanocytic differentiation. Furthermore, using a DNA targeted sequencing panel with next-generation sequencing, we identified a nonsense mutation in TSC Complex Subunit 2 (TSC2) gene, resulting in the formation of a premature termination codon. Moreover, the mutated genes found to be enriched in the PI3K-AKT pathway. The patient in this case had a favorable postoperative follow-up at 3 months. Conclusion: To the best of our knowledge, this study represents the first analysis of genotype mutations in AMLEC, providing valuable insights for future clinical practice. These findings have significant potential in guiding the understanding and management of AMLEC, paving the way for further research and advancements in the field.

11.
Gels ; 9(12)2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38131936

RESUMO

Hydrogel has been widely used in reservoir regulation for enhancing oil recovery, however, this process can experience negative influences on the properties and effects of the hydrogels. Therefore, developing novel hydrogels with excellent environmental responsiveness would improve the formation adaptability of hydrogels. In this study, novel polyvinyl polyamine hydrogels were synthesized by a ring-opening addition reaction between polyvinyl polyamines and polyethylene glycol glycidyl ether. The results of atomic force microscopy and transmission electron microscopy showed that the polyvinyl polyamine gel had a porous and irregular bulk structure and was endowed with water storage. With the temperature rising from 30 °C to 60 °C, the transmittance of diethylenetriamine hydrogel decreased from 84.3% to 18.8%, indicating that a phase transition had occurred. After the polyvinyl polyamine hydrogel with low initial viscosity was injected into the formation in the liquid phase, the increase of the reservoir temperature caused it to turn into an elastomer, thereby migrating to the depth of the reservoir and achieving effective plugging. Polyvinyl polyamine hydrogel could improve the profile of heterogeneous layers significantly by forcing subsequent fluids into the low permeability zone in the form of elastomers in the medium temperature reservoirs of 40-60 °C. The novel environmentally responsive polyvinyl polyamine hydrogels, capable of phase transformation with temperature, exhibited superior performance in recovering residual oil, which was beneficial for applications in reservoir profile control and oilfield development.

12.
ACS Omega ; 7(4): 3277-3283, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35128239

RESUMO

Confined compounds in SAPO-34 cages are important to understand the activation and deactivation mechanisms of the methanol-to-olefin process. In this work, gas chromatography-mass spectrometry (GC-MS) chromatograms of CCl4-extracted samples of used SAPO-34 were denoised by subtracting signals of air compounds and stationary phase bleeding of the chromatographic column, which enhanced the identification of trace compounds. In addition to the generally noted methyl aromatics, this work also identified alkanes, cycloalkanes, alkyl (ethyl, propyl, and butyl) compounds, partially saturated compounds, and bridged compounds. These novel identified trace compounds favor the evolution route depiction of monocyclic, bicyclic, tricyclic, tetracyclic, and multicore hydrocarbons in the SAPO-34 cage. Confined compounds should grow via step-by-step alkylation, cyclization, and aromatization processes. C2+ side chains, especially C3+, favor the growth of rings. Alkyldihydroindenes should be key intermediates between monocyclic and bicyclic aromatics. Bridged soluble compounds provide evidence that insoluble coke is formed across cages in the SAPO-34 crystal.

13.
RSC Adv ; 10(71): 43640-43652, 2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-35519670

RESUMO

Linear α-olefins are widely used as raw materials in the chemical industry. Selective ethylene oligomerization is an important development direction of the linear α-olefin production process. Iron-based catalysts have become a research hotspot in selective ethylene oligomerization due to their advantages like high activity, high selectivity and convenience of adjusting their ligand structures. In this paper, the research progress of catalysts for selective oligomerization of ethylene was reviewed in terms of the cocatalysts, ligand structure, and immobilization of homogeneous catalysts.

14.
Org Lett ; 21(16): 6259-6263, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31369287

RESUMO

The [4 + 1] annulation of benzamides and aldehydes for phthalide synthesis was achieved via rhenium-catalyzed C-H activation, which demonstrates an unprecedented reaction pattern distinct from those of other transition-metal catalyses. The reaction also features readily available starting materials, a wide scope for both electro-rich and electro-deficient substrates, and the elimination of homoannulation byproducts.

15.
Chem Commun (Camb) ; (38): 4848-50, 2005 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-16193135

RESUMO

Multiply-substituted iminocyclopentadienes were formed from Lewis acid-promoted reactions of zirconacyclopentadienes and isocyanates via a one-pot three-component coupling process; the C=O double bond of the RN=C=O moiety in the isocyanate was cleaved, and the isocyanates behaved formally as a one-carbon unit with Lewis acid-dependent and substituent-dependent reactions being realized.


Assuntos
Alcinos/química , Ciclopentanos/química , Ciclopentanos/síntese química , Isocianatos/química , Compostos Organometálicos/química , Zircônio/química , Estrutura Molecular
16.
Virol Sin ; 28(1): 24-35, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23385352

RESUMO

A quantitative real time reverse-transcription polymerase chain reaction (qRT-PCR) assay with specific primers recommended by the World Health Organization (WHO) has been widely used successfully for detection and monitoring of the pandemic H1N1/2009 influenza A virus. In this study, we report the design and characterization of a novel set of primers to be used in a qRT-PCR assay for detecting the pandemic H1N1/2009 virus. The newly designed primers target three regions that are highly conserved among the hemagglutinin (HA) genes of the pandemic H1N1/2009 viruses and are different from those targeted by the WHO-recommended primers. The qRT-PCR assays with the newly designed primers are highly specific, and as specific as the WHO-recommended primers for detecting pandemic H1N1/2009 viruses and other influenza viruses including influenza B viruses and influenza A viruses of human, swine, and raccoon dog origin. Furthermore, the qRT-PCR assays with the newly designed primers appeared to be at least 10-fold more sensitive than those with the WHO-recommended primers as the detection limits of the assays with our primers and the WHO-recommended primers were 2.5 and 25 copies of target RNA per reaction, respectively. When tested with 83 clinical samples, 32 were detected to be positive using the qRT-PCR assays with our designed primers, while only 25 were positive by the assays with the WHO-recommended primers. These results suggest that the qRT-PCR system with the newly designed primers represent a highly sensitive assay for diagnosis of the pandemic H1N1/2009 virus infection.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , China/epidemiologia , Primers do DNA/genética , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza B/genética , Vírus da Influenza B/isolamento & purificação , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Sensibilidade e Especificidade , Proteínas Virais/genética
17.
Artigo em Zh | MEDLINE | ID: mdl-22321415

RESUMO

OBJECTIVE: To investigate the clinical effect of orbit blowout fracture reconstruction under nasal endoscope. METHODS: Forty-one cases of orbit fracture were reconstructed for lost or damaged orbit under nasal endoscope through maxillary sinus, ethmoidal sinus or the both. RESULTS: Among the 35 cases of orbit blowout fracture, enophthalmos in 33 cases were completely improved, 29 cases were symmetrical to normal eye after operation without diplopia except that 6 cases had slight enophthalmos accompanied with slight diplopia. Among these 6 cases, 4 cases returned to normal without diplopia 6 months after operation. In the 6 cases of orbit non-blowout fracture, 4 cases were symmetrical to normal eye after operation without enophthalmos, diplopia and facial malformation. One case had slight enophthalmos and diplopia, 1 case had slight enophthalmos with slight facial malformation. CONCLUSIONS: The surgery under nasal endoscope is safe and credible. The method can be easily mastered and its complication is less.


Assuntos
Nariz/cirurgia , Fraturas Orbitárias/cirurgia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Otorrinolaringológicos/métodos , Adulto Jovem
18.
Artigo em Zh | MEDLINE | ID: mdl-19558886

RESUMO

OBJECTIVE: To evaluate the therapeutic efficacy of combined treatment with surgical decompression and drug for traumatic optic neuropathy (TON) and analyze the influential factors. METHODS: A retrospective study on 69 patients (70 eyes) with TON treated with optic canal decompression through transnasal endoscopic approach and drug was conducted. The visual acuity was divided into 5 grades: no light perception (NLP), light perception (LP), hand move, count finger, > 0.02, marked as I-V respectively. Of 40 eyes with grade I, 18 eyes received emergency operation for severe optic canal fracture confirmed by CT; 22 eyes received corticosteroid therapy firstly and then operation. Of 30 eyes above grade I, 16 eyes with optic canal fracture confirmed by CT received emergency operation; 14 eyes received corticosteroid therapy firstly and 3 days later received operation. Postoperative follow-up lasted 3-12 months to observe the recovery of visual acuity. RESULTS: The therapeutic efficacy of patients with the visual acuity of LP and above LP was better than that of NLP (90.0% to 27.5%), the difference had statistical significance (chi(2) = 26.98, P < 0.001). In operated group, the therapeutic efficacy in patients whose visual acuity was improved from NLP after glucocorticoid therapy (80.0%) was better than that of the patients with no improvement (5.9%), the difference had statistical significance (chi(2) = 12.09, P < 0.001). CONCLUSION: The imaging findings of optic canal fracture can not be used as determinants for operation. The patients with NLP whose visual acuity had no improvement after corticosteroid therapy are poor candidates for surgical decompression. The visual acuity before treatment is the main factor affecting the therapeutic efficacy.


Assuntos
Traumatismos do Nervo Óptico/tratamento farmacológico , Traumatismos do Nervo Óptico/cirurgia , Adolescente , Adulto , Criança , Terapia Combinada , Descompressão Cirúrgica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
19.
J Org Chem ; 70(13): 5150-6, 2005 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-15960518

RESUMO

Stereodefined multisubstituted dienamides could be concisely prepared in high yields by direct addition of 1-lithiobutadiene derivatives to both N-aryl and N-alkyl isocyanates. Electrophilic cyclization of these dienamides was achieved to generate substituted cyclic iminoethers in excellent yields with perfect selectivity. When treated with 12 N aqueous HCl, dienamides underwent efficient and selective electrophilic cyclization to afford cyclic imidate derivatives. When treated with NBS, monobrominated or double-brominated cyclic iminoethers were formed.

20.
Chemistry ; 10(14): 3444-50, 2004 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-15252790

RESUMO

1,4-Dilithiobutadiene derivatives 1, 1,4-bis(bromomagnesio)butadiene derivatives 2 and metallacyclic (1,3-butadiene-1,4-diyl)magnesium reagents 3 were prepared and their reactions with ketones, aldehydes, and PhNO were investigated. Multiply substituted cyclopentadienes and N-Ph pyrroles were formed by unprecedented reaction conditions. The carbonyl group of aldehydes and ketones was deoxygenated during the reaction and behaved formally as a one-carbon unit; the N==O moiety of PhNO was cleaved to afford N-Ph pyrrole derivatives. Furthermore, different reactivities among these three types of reagents 1, 2 and 3 were revealed. The 1,4-dilithium reagents 1 readily reacted with both aldehydes and ketones; the 1,4-dimagnesium reagents 2 reacted with aldehydes, but not ketones; the metallacyclopentadiene reagents of magnesium 3 showed higher reactivity and did react with ketones.

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