Flowmicro In-Line Analysis-Driven Design of Reactions Mediated by Unstable Intermediates: Flash Monitoring Approach.

The direct observation of reactive intermediates is an important issue for organic synthesis. However, intermediates with an extreme instability are hard to be monitored by common spectroscopic methods such as FTIR. We have developed synthetic method utilizing flow microreactors, which enables a generation and reactions of unstable intermediates. Herein we report that, based on our flowmicro techniques, we developed an in-line analysis method for reactive intermediates in increments of milliseconds. We demonstrated the direct observation of the living and dead species of the anionic polymerization of alkyl methacrylates. The direct information of the living species enabled the anionic polymerization and copolymerization of oligo(ethylene glycol) methyl ether methacrylates, which is the important but difficult reaction in the conventional method.

Flowmicro in-Line Analysis-Driven Design of Reactions Mediated by Unstable Intermediates: Flash Monitoring Approach.

Invited for the cover of this issue is the group of Aiichiro Nagaki, Yosuke Ashikari and co-workers at Hokkaido University. The image depicts flash monitoring of reactive intermediate in a flow microreactor. Read the full text of the article at 10.1002/chem.202303774.

Not taking sick leave for gynecologic cancer treatment is negatively associated with returning to the same workplace.

BACKGROUND: Gynecologic cancers are one of the most common types of malignancies in working-age women. We aimed to determine the factors that impede women from returning to the same workplace after treatment for such cancers. METHODS: A questionnaire-based survey was conducted on 194 women who underwent treatment for gynecologic cancer at the Okayama University (≥1 year after cancer treatment and <65 years of age). We performed a logistic regression analysis to determine the relationship between returning to the same workplace and not taking sick leave. RESULTS: The median age at diagnosis was 49.0 years, and the median time from cancer treatment to questionnaire completion was 3.8 years. Not returning to the same workplace was positively associated with not being regularly employed (P = 0.018), short work time per day (P = 0.023), low personal income (P = 0.004), not taking sick leave (P < 0.001), advanced cancer stage (P = 0.018) and long treatment time (P = 0.032). Interestingly, not taking sick leave was strongly associated with not returning to the same workplace in the multivariable analysis (P < 0.001). CONCLUSIONS: Not taking sick leave likely was negatively associated with returning to the same workplace after the treatment for gynecologic cancer. Therefore, we suggest that steps be taken to formally introduce a sick leave system over and above the paid leave system in Japan.

Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process.

Electrochemically generated amidyl radical species produced distinct inter- or intramolecular hydroamination reaction products via a proton-coupled electron transfer (PCET) mechanism. Cyclic voltammetry (CV) analysis indicated that the chemoselectivity was derived from the size of the hydrogen bond complex, which consisted of the carbamate substrate and phosphate base, and could be controlled using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as an additive. These results provide fundamental insights for the design of PCET-based redox reaction systems under electrochemical conditions.

External Flash Generation of Carbenoids Enables Monodeuteration of Dihalomethanes.

In this study, incorporation of one deuterium atom was achieved by H-D exchange of one of the two identical methylene protons in various dihalomethanes (halogen=Cl, Br, and I) through a rapid-mixing microflow reaction of lithium diisopropylamide as a strong base and deuterated methanol as a deuteration reagent. Generation of highly unstable carbenoid intermediate and suppression of its decomposition were successfully controlled under high flow-rate conditions. Monofunctionalization of diiodomethane afforded various building blocks composed of boryl, stannyl, and silyl groups. The monodeuterated diiodomethane, which served as a deuterated C1 source, was subsequently subjected to diverted functionalization methods to afford various products including biologically important molecules bearing isotope labelling at specific positions and homologation products with monodeuteration.

ADAR1 and AZIN1 RNA editing function as an oncogene and contributes to immortalization in endometrial cancer.

OBJECTIVE: Adenosine-to-inosine (A-to-I) RNA editing is a recently described epigenetic modification, which is believed to constitute a key oncogenic mechanism in human cancers. However, its functional role and clinical significance in endometrial cancer (EC) remain unclear. METHODS: Adenosine Deaminase family Acting on RNA1 (ADAR1) expression and Antizyme inhibitor 1 (AZIN1) RNA editing were examined to clarify the correlation with clinicopathological parameters and prognosis in EC patients. The biological functions and inhibitory effects of ADAR1 knockdown were investigated in JHUCS-1 and TU-ECS-1 EC cell lines. RESULTS: ADAR1 showed significant association with worse histology (P = 0.006), and lymph vascular space involvement (P = 0.049) in EC. The level of AZIN1 RNA editing was also significantly associated with worse histology (P = 0.012). ADAR1 expression was significantly correlated with AZIN1 RNA editing level (R = 0.729, R2 = 0.547, P < 0.001). Multivariate analysis indicated that higher ADAR1 expression along with AZIN1 RNA editing is an independent predictor of prognosis in EC patients (P = 0.015). Knockdown of ADAR1 led to increased MDA-5, RIG-I, PKR, and IRF-7 expression, which in turn resulted in increased levels of Bak and apoptosis in EC cells. CONCLUSIONS: High ADAR1 expression along with AZIN1 RNA editing could be a predictor of worse prognosis in EC. ADAR1 could be a potential therapeutic target in EC patients.

The Combination of D-dimer and Glasgow Prognostic Score Can Be Useful in Predicting VTE in Patients with Stage IIIC and IVA Ovarian Cancer.

Cancer patients have increased risk of venous thromboembolism (VTE) that must be assessed before treatment. This study aimed to determine effective VTE biomarkers in gynecologic cancer (GC). We investigated the correlation between D-dimer levels, Khorana risk score (KRS), Glasgow prognostic score (GPS), and VTE in 1499 GC patients (583 cervical cancer (CC), 621 endometrial cancer (EC), and 295 ovarian cancer (OC) patients) treated at our institution between January 2008 and December 2019. χ2 and Mann-Whitney U-tests were used to determine statistical significance. We used receiver operating characteristic-curve analysis to evaluate the discriminatory ability of each parameter. D-dimer levels were significantly correlated with KRS and GPS in patients with GC. VTE was diagnosed in 11 CC (1.9%), 27 EC (4.3%), and 39 OC patients (13.2%). Optimal D-dimer cut-off values for VTE were 3.1, 3.2, and 3.9 µg/ml in CC, EC and OC patients, respectively. D-dimer could significantly predict VTE in all GC patients. Furthermore, D-dimer combined with GPS was more accurate in predicting VTE than other VTE biomarkers in stage IIIC and IVA OC (AUC: 0.846; p<0.001). This study demonstrates that combined D-dimer and GPS are useful in predicting VTE in patients with OC.

Oxidation Potential Gap (ΔEox ): The Hidden Parameter in Redox Chemistry.

Oxidative biaryl coupling of aryls with different electronic features generally fails. However, this has not been systematically studied via theoretical analysis, and thus, the crucial factor governing coupling efficiency remains unclear. Herein, we propose that the "oxidation potential gap (ΔEox )" is a key parameter in predicting the efficiency of an intramolecular oxidative coupling reaction, with ΔEox defined as a difference in the oxidation potentials of the relevant aromatic rings. Our experimental and computational analyses revealed that the efficiency of an aromatic intramolecular coupling reaction correlates with the activation energy (ΔE≠ ) of C-C bond formation of the radical cation intermediates. Furthermore, ΔE≠ correlates with ΔEox . Therefore, we demonstrate the tuning of ΔEox by attaching cleavable extra electron-donating/-withdrawing groups, enabling the rational synthesis of a phenanthridone skeleton using aromatic rings with an electronic gap.

Hydrosilane-Mediated Electrochemical Reduction of Amides.

Electrochemical reduction of amides was achieved by using a hydrosilane without any toxic or expensive metals. The key reactive ketyl radical intermediate was generated by cathodic reduction. Continuous reaction with anodically generated silyl radicals or zinc bromide resulted in chemoselective deoxygenation to give the corresponding amines.

Design, synthesis and biological evaluation of simplified analogues of MraY inhibitory natural product with rigid scaffold.

Muraymycins and caprazamycins are strong inhibitors of MraY, which is responsible for peptidoglycan biosynthesis. Although they are promising antibacterial agents with a novel mode of action, their chemical structures are rather complex. This study investigated the simplification of these natural products by structure-based drug design, synthesis, and biological evaluation. We developed a simplified rigid scaffold with an arylalkyne moiety, which shows sub-micromolar MraY inhibitory activity. The scaffold is suitable for further investigating the structure-activity relationship by virtue of our synthetic strategy, where the substituent of interest is installed in the last stage of synthesis. This scaffold shows the potential for further use in optimizing MraY inhibitory and antibacterial activities.

Relationship Between Olfactory Disturbance After Acute Ischemic Stroke and Latent Thalamic Hypoperfusion.

Odor detection, recognition, and identification were assessed in 19 acute ischemic stroke patients who had no magnetic resonance imaging-detectable thalamic lesions but in whom technetium-99m ethyl cysteinate dimer single photon emission tomography revealed thalamic hypoperfusion. Although these patients were unaware of reduced olfactory function, they exhibited significantly lower scores in tests for odor identification and recognition threshold as compared with 9 ischemic stroke controls that had normal thalamic hypoperfusion. However, absolute odor detection thresholds were similar in the 2 groups. These results demonstrate the usefulness of cerebral perfusion scintigraphy in assessing sensory loss after ischemic stroke and provide further evidence for the role of the thalamus in olfaction.

Introduction of the Purdue Pegboard Test for fine assessment of severity of cervical myelopathy before and after surgery.

[Purpose] To evaluate the severity of symptoms before and after cervical myelopathy surgery using the Simple Test for Evaluating hand Function. Because a test ceiling effect was observed in patients with less severe forms of myelopathy, we investigated the correlation between and accuracy of several different tests in order to clarify the usefulness of the Purdue Pegboard Test for evaluation of one or both hands. [Participants and Methods] Thirty-four patients (6 females and 28 males; mean age, 64.5 years) were examined, and scores were determined for each of the following tests: Purdue Pegboard Test; Simple Test for Evaluating hand Function; Japanese Orthopedic Association assessment; and Disabilities of the Arm, Shoulder, and Hand assessment. Correlations between scores of different tests were then determined. The cut-off values used for the Purdue Pegboard Test and the Simple Test for Evaluating hand Function were determined using the area under the receiver operating characteristic curve to assess the use of chopsticks. [Results] The Purdue Pegboard Test assembly task correlated moderately with the Japanese Orthopedic Association and Disabilities of the Arm, Shoulder, and Hand scores. In the receiver operating characteristic curve analyses, the Purdue Pegboard Test cut-off value was 11 and the Simple Test for Evaluating hand Function cut-off value was 90. [Conclusion] The Purdue Pegboard Test is useful for evaluating manual dexterity and coordination in both hands in patients with cervical myelopathy.

Recent Progress on Cyclic Nitrenoid Precursors in Transition-Metal-Catalyzed Nitrene-Transfer Reactions.

Nitrene-transfer reactions are powerful synthetic tools for the direct incorporation of nitrogen atoms into organic molecules. The discovery of novel nitrene-transfer reactions has been dominantly supported not only by improvements in transition-metal catalysts but also by the employment of novel precursors of nitrenoids. Since pioneering work involving the use of organic azides and iminoiodinanes as practical synthetic tools for nitrogen-containing compounds was reported, a new approach using various N-heterocycles containing strain energy or a weak bond has emerged. In this review, we briefly summarize the history of nitrene-transfer chemistry from the viewpoint of its precursors. In particular, the use of N-heterocycles such as 2H-azirines, 1,4,2-dioxazol-5-ones, 1,2,4-oxadiazol-5-ones, isoxazol-5(4H)-ones, and isoxazoles is comprehensively described, showing the recent remarkable progress in this chemistry.

Development of the modified simple test for evaluating hand function (modified STEF): Construct, reliability, validity, and responsiveness.

STUDY DESIGN: Clinimetric evaluation study. INTRODUCTION: Despite the availability of numerous performance tests to measure finger dexterity, there is no international consensus on hand function evaluation. PURPOSE OF THE STUDY: To evaluate the reliability, validity, and responsiveness of the modified version of the simple test for evaluating hand function (STEF), which is widely used in Japan. METHODS: The intrarater (n = 40) and inter-rater (n = 32) reliability of the modified STEF was evaluated by calculating the intraclass correlation coefficient (ICC), models (1,1) and (2,1), respectively, in healthy individuals. The criterion validity of the modified STEF (n = 50) was evaluated by calculating the Pearson correlation coefficient relative to the STEF, the Purdue pegboard test (PPT), and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. The standardized response mean of the scores was calculated to determine responsiveness (n = 35). The modified STEF was used prospectively to measure the change in hand function in a cohort of patients with hand trauma injuries and inflammatory diseases (n = 30), as well as in a cohort of patients with cervical spondylosis (n = 20), from preoperative baseline to 1 and 3 months postoperatively. RESULTS: ICC1.1 and ICC2.1 values were ≥0.80, indicative of high intrarater and inter-rater reliability. All correlation coefficients were significant (P < .05): STEF (r = 0.89), PPT (r = 0.69), and DASH (r = -0.34). The standardized response mean indicated greater responsiveness of the modified STEF (0.89) than the STEF (0.71) and PPT (0.68) but a lower responsiveness than the DASH (1.11). DISCUSSION: It must be mentioned that modified STEF and DASH cannot be compared without caution. The two types of tools should complement each other when measuring someone's activity and participation level. CONCLUSIONS: The modified STEF is a reliable measurement tool, with a moderate positive correlation with the PPT and a greater responsiveness than the STEF and PPT.

Synthesis of Ribo-Azanucleosides by Anodic Oxidation: Reactivity Control of Intermediate for Efficient Access to Pharmacophores.

Azanucleosides, the sugar-modified nucleoside analogues, have various biological activities, while their efficient synthetic strategy is still under development. Herein, a novel method for the synthesis of pharmaceutically relevant azanucleosides, ß-anomers of ribo-azanucleosides, by means of site-specific anodic C-H activation by using a nitroalkane-lithium perchlorate medium is reported. A mechanistic study of the electrochemical reaction and the armed/disarmed concept from traditional glycochemistry revealed that the 2'-substituent has a significant effect on the reactivity of prolinol derivative, and suitable carboxylic acid additives can control the reactivity of the intermediate species, an iminium cation equivalent. Finally, this method was demonstrated to be applicable for the synthesis of ß-anomers of ribo-azanucleosides with all four nucleobases in a stereoselective manner.

Asymmetric Synthesis of 2H-Azirines with a Tetrasubstituted Stereocenter by Enantioselective Ring Contraction of Isoxazoles.

Highly strained 2H-azirines with a tetrasubstituted stereocenter were synthesized by the enantioselective isomerization of isoxazoles with a chiral diene-rhodium catalyst system. The effect of ligands and the coordination behavior support the proposed catalytic cycle in which the coordination site is fixed in favor of efficient enantiodiscrimination by a bulky substituent of the ligand. In silico studies also support the existence of a rhodium-imido complex as a key intermediate for enantiodiscrimination.

Generation of Stable Ruthenium(IV) Ketimido Complexes by Oxidative Addition of Oxime Esters to Ruthenium(II): Reactivity Studies Based on Electronic Properties of the Ru-N Bond.

The reaction of an oxime ester with [Ru(PPh3 )3 X2 ] proceeded smoothly at room temperature to afford a stable RuIV ketimido complex as oxidative adduct. The structure of the complex was unambiguously determined by X-ray crystallographic analysis, which showed an almost linear Ru-N-C array. The electronic properties of the nitrogen atom were estimated by DFT calculations, and the results suggested double-bond character of the Ru-N bond. Kinetic studies and consideration of the substituent effect on the oxime ester led to the proposal of a reaction mechanism involving oxidative addition, which could proceed by N,O-chelating coordination to the Ru center prior to N-O bond cleavage. The obtained Ru ketimido complex could be transformed into a ruthenacycle by C-H activation by a concerted metalation-deprotonation mechanism in dichloromethane/methanol. Ru ketimido complexes with a tethered alkyne or alkene moiety underwent chloroamination of unsaturated C-C bonds followed by C-H activation, which resulted in the formation of a ruthenacycle. Considering the LUMO of an isolated Ru ketimido complex, the chloroamination should proceed by a synchronous 1,3-dipolar cycloaddition-type mechanism. Insight into the character and reactivity of Ru ketimido complexes will be helpful for developments in the catalytic transformation of oxime esters.

Synthesis of 2H-Azirines by Iridium-Catalyzed Decarboxylative Ring Contraction of Isoxazol-5(4H)-ones.

A phosphine-free iridium-catalyzed reaction of isoxazol-5(4H)-ones (isoxazolones) has been developed, and affords 2H-azirines through decarboxylation and ring contraction. This method provides an efficient and environmentally benign protocol which could replace the conventional approaches used to synthesize 2H-azirines.

Palladium-catalyzed aza-Wittig-type condensation of isoxazol-5(4H)-ones with aldehydes.

This paper describes the development of a palladium-catalyzed decarboxylative inter- and intramolecular condensation reaction of isoxazol-5(4 H)-ones with carbonyl compounds in the presence of PPh3 , giving various 2-azabuta-1,3-dienes or pyrroles in moderate to high yields.