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A simple protocol to overcome the explosive pentafluoroethylation of carbonyl compounds by HFC-125 is described. The use of potassium (K) bases with triglyme or tetraglyme as a solvent safely yields the pentafluoroethylation products in good to high yields. The experimental results suggest that an encapsulation of the K cation by glymes as K(glyme)2 inhibits the contact between the K cation and the reactive anionic pentafluoroethyl counterion, preventing their transformation into KF and explosive tetrafluoroethylene (TFE). The generation of sterically demanding [K(G3)2]+ and [K(G4)2]+ is an effective way as an unstable pentafluoroethyl anion reservoir.
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A straightforward method that enables the formation of biologically attractive trifluoromethyl ketones from readily available methyl esters using the potent greenhouse gas fluoroform (HCF3, HFC-23) was developed. The combination of fluoroform and KHMDS in triglyme at -40 °C was effective for this transformation, with good yields as high as 92%. Substrate scope of the trifluoromethylation procedure was explored for aromatic, aliphatic, and conjugated methyl esters. This study presents a straightforward trifluoromethylation process of various methyl esters that convert well to the corresponding trifluoromethyl ketones. The tolerance of various pharmacophores under the reaction conditions was also explored.
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Fluoroform, HFC-23, is an industrial byproduct from the synthesis of polytetrafluoroethylene and is a vastly underused resource; however, its physicochemical properties have hindered progress toward synthetic uses. Herein, we describe the use of HFC-23 as a cheap trifluoromethylating agent in two reactions for the highly diastereoselective synthesis of medicinally attractive chiral amines with two stereogenic carbon centers: a base-dependent, stereodivergent nucleophilic addition to synthesize enantioenriched vicinal diamines and a tandem nucleophilic addition/aza-Michael sequence toward enantioenriched isoindolines.
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Endoscopía del Sistema Digestivo , Neoplasias Pancreáticas , Humanos , Endoscopía del Sistema Digestivo/métodos , Carcinoma Ductal Pancreático/cirugía , Carcinoma Ductal Pancreático/diagnóstico , Neoplasias Intraductales Pancreáticas/cirugía , Masculino , Adenocarcinoma Mucinoso/cirugía , Anciano , FemeninoRESUMEN
Protein-protein interaction (PPI) analysis is very important for elucidating the functions of proteins because many proteins execute their functions in living cells by interacting with one another. In PPI analysis, methods using the sensor chips are widely employed to obtain quantitative data. However, these methods require that the target proteins be immobilized on the sensor chips, and the immobilization processes can affect the binding of the target proteins to their binding partners. In the present work, we propose a PPI analysis system in which the surface of the living cells is utilized as a sensing platform. In our approach, the target protein is displayed on the cell surface by expressing it as a fusion protein with a membrane protein, and the PPI analysis is then conducted by applying its binding partner labeled with a fluorescent dye to the cell surface. We have constructed a model of this binding analysis system using the interaction between biotin protein ligase (BPL) and biotin carboxyl carrier protein (BCCP), where BCCP was displayed on the cell surface and BPL labeled with fluorescein was applied to the cell surface. Here, a red fluorescent protein, mApple, was attached to the C-terminus of the fusion protein of BCCP with a membrane protein. We evaluated the binding level of the labeled BPL by using the intensity ratios of fluorescence from fluorescein to that from mApple. We found that the binding level of the labeled BPL was stably evaluated at least across 60 min observation period and estimated the binding dissociation constant between BPL and BCCP by equilibrium analysis to be 0.33 ± 0.05 µM.
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Proteínas Arqueales , Fluorescencia , Proteínas de la Membrana , Fluoresceínas , Biotina/metabolismoRESUMEN
Objectives Dermatomyositis (DM) is often associated with fatal anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive rapidly progressive interstitial lung disease (RP-ILD). RP-ILD often fails to respond to intensive treatment and has a poor prognosis. We examined the effectiveness of early plasma exchange therapy plus intensive treatment with high-dose corticosteroids and multiple immunosuppressants. Methods Autoantibodies were identified by an immunoprecipitation assay and enzyme-linked immunosorbent assay. All clinical and immunological data were collected retrospectively from medical charts. We divided patients into two groups based on treatment regimen: intensive immunosuppressive therapy alone as initial treatment (IS group) and early initiation of plasma exchange (PE) plus intensive immunosuppressive therapy (ePE group). Early PE therapy was designated if PE therapy was initiated within two weeks of starting treatment. Comparisons of the treatment response and prognosis between groups were performed. Patients Anti-MDA5-positive DM with RP-ILD was screened. Results Forty-four RP-ILD and DM patients had anti-MDA5 antibodies. Four patients were excluded because they died before receiving sufficient combined immunosuppressive therapy or before the evaluation of the immunosuppressive treatment effectiveness (IS, n=31; ePE, n=9). All 9 patients in the ePE group had improved respiratory symptoms and were alive, whereas 12 of 31 patients in the IS group died (100 vs. 61%, p=0.037). Of the 8 patients who had 2 values for a poor prognosis, indicating the highest risk for death using the MCK model, 3 of 3 patients in the ePE group and 2 of 5 in the IS group were alive (100 vs. 40%, p=0.20). Conclusion The early initiation of ePE therapy plus intensive immunosuppressive therapy was effective for patients with DM and refractory RP-ILD.
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Dermatomiositis , Enfermedades Pulmonares Intersticiales , Humanos , Intercambio Plasmático/métodos , Dermatomiositis/complicaciones , Dermatomiositis/terapia , Dermatomiositis/diagnóstico , Estudios Retrospectivos , Pronóstico , Inmunosupresores/uso terapéutico , Enfermedades Pulmonares Intersticiales/complicaciones , Enfermedades Pulmonares Intersticiales/terapia , Autoanticuerpos , Helicasa Inducida por Interferón IFIH1 , Progresión de la EnfermedadRESUMEN
INTRODUCTION: Stomach metastasis is rare, and there are few reports on its endoscopic features. Herein, we focused on the endoscopic features and discussed and reviewed the clinicopathological characteristics of metastatic gastric tumors. METHODS: We conducted an analysis on the clinicopathological features of individuals with gastric metastases originating from solid organ tumors at the Department of Gastroenterology, Toranomon Hospital, Minato-ku, Tokyo, Japan. Thirty-one cases were identified and evaluated for histology, initial presentation, endoscopic findings, lesion locations, treatment courses, and overall survival of the patients. RESULTS: Endoscopic findings resembling submucosal tumors were present in five cases (16%), and those with a morphology similar to that of primary gastric cancer were present in 26 cases (84%). In addition, seven patients (22%) were diagnosed with gastric metastasis due to a suspected biopsy of early gastric cancer. Solitary metastasis (21 patients, 67.7%) was more common than multiple metastases (10 patients, 32.2%). The median time from primary tumor to diagnosis was 36 months, and survival after metastasis was 19 months. The overall survival (OS) after the diagnosis of the primary tumor was 22 months for esophageal cancer, 25 months for lung cancer, and 100 months for breast cancer, and the OS after the diagnosis of gastric metastasis was almost the same. The average time from the diagnosis of the primary tumor to the diagnosis of gastric metastasis (*timespan) was more than seven years for breast and kidney cancers. CONCLUSION: As the prognosis of patients with cancer gradually improves, they develop metastases more frequently. Understanding the endoscopic findings and information about a patient's clinical history is useful to correctly diagnose gastric metastases.
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Alveolar echinococcosis (AE), caused by Echinococcus multilocularis, is an aggressive and potentially critical infestation that primarily affects the liver and can metastasize to any part of the body. We herein report two cases of echinococcosis, which could be differentiated from malignancy on imaging studies, with infections of the liver and mediastinal lymph nodes, and also associated with systemic disseminated lesions. AE is a very invasive infectious disease, and in order to detect such lesions at an early stage when they are still resectable, it is necessary to understand the characteristic imaging findings and determine the patient's current medical history.
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Gastric cancer without Helicobacter pylori infection accounts for less than 1% of all gastric cancers, and is generally considered to be less invasive. This report describes a rare case of H. pylori-uninfected gastric cancer with deep submucosal invasion and lymph node metastasis. Endoscopic submucosal dissection was performed, and pathological examination revealed tubular adenocarcinoma with deep submucosal invasion. We diagnosed foveolar-type gastric adenocarcinoma. While many cases of foveolar-type gastric adenocarcinoma, especially of the white elevated type, are reported as early stage gastric cancer, this case is very rare because it showed submucosal invasion and lymph node metastasis.
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Dermatomyositis (DM) is a categorised as one of idiopathic inflammatory myopathy (IIM) indicated by symmetrical proximal muscle weakness as well as characteristic cutaneous manifestations typical of DM. Clinically amyopathic dermatomyositis (CADM), a subtype of DM, shows only the skin involvement without any clinical signs of myositis. This condition is often associated with fatal anti-MDA5 antibody-positive rapidly progressive interstitial lung disease (RP-ILD), especially in Eastern Asian populations. Here, we report a CADM patient with anti-MDA5 antibody-positive RP-ILD whom we successfully treated by early initiation of plasma exchange (PE) together with multiple immunosuppressive therapies. In this patient, initial treatment with high-dose prednisolone (PSL), tacrolimus and intermittent intravenous cyclophosphamide had resulted in no obvious improvement in the respiratory condition. Therefore, soon after the first evaluation, we initiated PE therapy in addition to these multiple immunosuppressive therapies. Although the patient had pneumomediastinum, cytomegalovirus and fungal infections over the clinical course, RP-ILD did gradually improved and the anti-MDA5 titre decreased down to within the normal range paralleled by improvement in the patient's respiratory condition.
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Autoanticuerpos/sangre , Dermatomiositis/terapia , Helicasa Inducida por Interferón IFIH1/inmunología , Enfermedades Pulmonares Intersticiales/terapia , Intercambio Plasmático/métodos , Anciano , Infecciones por Citomegalovirus , Dermatomiositis/inmunología , Progresión de la Enfermedad , Femenino , Humanos , Enfermedades Pulmonares Intersticiales/inmunología , Enfisema Mediastínico/complicaciones , Micosis/complicaciones , Prednisolona/uso terapéuticoRESUMEN
Invited for this month's cover picture is the group of Norio Shibata at the Nagoya Institute of Technology (Japan). The cover picture shows an image related to the perpetual motion machine of the second kind in the eighteenth century, and "alchemy". Our biggest challenge on the path to the results presented in this paper was the creation of alchemy using fluorine chemistry. Read the full text of their Communication at 10.1002/open.201800286.
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A micro-flow nucleophilic trifluoromethylation of carbonyl compounds using gaseous fluoroform was developed. This method also allows the first micro-flow transformation of N-sulfinylimines into trifluoromethyl amines with excellent diastereoselectivity. To demonstrate the synthetic utility of this micro-flow synthesis, the formal micro-flow synthesis of Efavirenz is described.
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The palladium-catalyzed asymmetric decarboxylative allylic alkylation of trifluoromethoxy allyl enol carbonates afforded enantioenriched α-trifluoromethoxy allyl ketones that feature a tetrasubstituted α-stereogenic center in excellent yield and high enantioselectivity. The method was further extended to the asymmetric synthesis of α-difluoromethoxy and α-methoxy allyl ketones, which proceeded under similar catalytic conditions.
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Efavirenz is manufactured worldwide, and its asymmetric synthesis requires a complex organometallic approach, while an organocatalytic approach is far less efficient. The first highly enantioselective approach is disclosed for the synthesis of Efavirenz under nonmetal organocatalysis with up to 93% ee for the Merck intermediate and 91% ee for the Lonsa intermediate using novel alkynyl cinchona catalysts.
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Fluoroform (HCF3, HFC-23) is a side product in the manufacture of polytetrafluoroethylene (Teflon). Despite its attractive properties, taming HCF3 for trifluoromethylation is quite problematic owing to its low acidity and the lability of the naked trifluoromethyl carbanion generated from HCF3. Herein we report the organic-superbase-catalyzed trifluoromethylation of ketones and arylsulfonyl fluorides by HCF3. The reactions were carried out by using a newly developed "superbase organocatalyst system" consisting of catalytic amounts of P4-tBu and N(SiMe3)3. A series of aryl and alkyl ketones were converted into the corresponding α-trifluoromethyl carbinols in good yields under the organocatalysis conditions in THF. The superbase organocatalytic system can also be applied to the trifluoromethylation of arylsulfonyl fluorides for biologically important aryl triflones in THF or DMF in good yields. Protonated P4-tBu, H[P4-tBu](+), is suggested to be crucial for the catalytic process. This new catalytic methodology using HCF3 is expected to expand the range of synthetic applications of trifluoromethylation.