Exploring the optimal range of central venous pressure in sepsis and septic shock patients: A retrospective study in 208 hospitals.

BACKGROUND: The aim of this study was to investigate the optimal CVP range in sepsis and septic shock patients admitted to intensive care unit. METHODS: We performed a retrospective study with adult sepsis patients with CVP records based on the eICU Collaborative Research Database. Multivariable logistic regression was performed to explore the associations between CVP level and hospital mortality. Non-linear correlations and optimal CVP range were explored using restricted cubic splines (RCS). RESULTS: A total of 5302 sepsis patients were included in this study. Patients in 4-8 mmHg group owned the lowest odds ratio for raw hospital mortality (19.7%). The logistic regression analyses revealed that hospital death risk increased significantly when mean CVP level exceeds 12 mmHg compared to 4-8 mmHg level. U-shaped association of CVP with hospital mortality was revealed by RCS model in septic shock patients and the optimal range was 5.6-12 mmHg. While, there was a J-shaped trend for non-septic shock patients. For non-septic shock patients, patients had an increased risk of hospital death only if CVP exceeded 11 mmHg. CONCLUSIONS: We observed U-shaped association between mean CVP level and hospital mortality in septic shock patients and J-shaped association in non-septic shock patients. This may imply that patients with different severity of sepsis have different CVP requirements. We need to monitor and manage CVP according to the circulatory status of the sepsis patient.

Pharmacokinetics of nirmatrelvir/ritonavir and the drug-drug interaction with calcineurin inhibitor in renal transplant recipients.

OBJECTIVES: To describe the pharmacokinetic (PK) characteristics of nirmatrelvir/ritonavir in renal transplant recipients and explore the potential factors that related to the PK variance of nirmatrelvir/ritonavir and its interaction with calcineurin inhibitor (CNI). METHODS: Renal transplant recipients treated with CNI and nirmatrelvir/ritonavir were prospectively enrolled. Steady-state plasma concentrations of nirmatrelvir/ritonavir were determined by high-performance liquid chromatography-tandem mass spectrometry, and the PK parameters were calculated using non-compartmental analysis. Spearman correlation analysis was used for exploring influencing factors. RESULTS: A total of eight recipients were enrolled; for nirmatrelvir and ritonavir, AUC/dose was 0.24179 ± 0.14495 and 0.06196 ± 0.03767 µg·h·mL-1·mg-1. Red blood cell (RBC), hematocrit (Ht), hemoglobins (Hb), and creatinine clearance (Ccr) were negatively correlated with AUC/dose of nirmatrelvir, while Ccr, CYP3A5 genotype, and CYP3A4 genotype were related to the AUC/dose of ritonavir. Ccr was negatively correlated with the C0/dose of tacrolimus (TAC) after termination of nirmatrelvir/ritonavir (rs = -0.943, p = 0.008). CONCLUSIONS: The PK characteristics of nirmatrelvir/ritonavir vary greatly among renal transplant recipients. Factors including Ccr and CYP3A5 genotype were related to the in vivo exposure of nirmatrelvir/ritonavir. During the whole process before and after nirmatrelvir/ritonavir therapy, it is recommended to adjust the CNI basing on renal function to avoid CNI toxicity exposure.

DLL1/NOTCH1 signaling pathway maintain angiogenesis in meniscus development and degeneration.

OBJECTIVES: The decline in vascular capacity within the meniscus is a well-documented phenomenon during both development and degeneration. Maintaining vascular integrity has been proposed as a potential therapeutic strategy for osteoarthritis. Therefore, our study aims to investigate the characteristics of endothelial cells and blood vessels in embryonic and degenerated meniscus tissues. METHODS: Human embryonic and mature menisci were used for histological analyses. Single-cell RNA sequencing was used to identify cell clusters and their significant genes in embryo meniscus to uncover characteristic of endothelial cells. Computer analysis and various staining techniques were used to characterize vessels in development and osteoarthritis meniscus. RESULTS: Vessels structure first observed in E12w and increasing in E14w. Vessels were veins majorly and arteries growth in E35w. Endothelial cells located not only perivascular but also in the surface of meniscus. The expression of DLL1 was observed to be significantly altered in endothelial cells within the vascular network that failed to form. Meniscus tissues affected by osteoarthritis, characterized by diminished vascular capacity, displayed reduced levels of DLL1 expression. Experiment in vitro confirmed DLL1/NOTCH1 be vital to angiogenesis. CONCLUSION: Lack of DLL1/NOTCH1 signaling pathway was mechanism of vascular declination in development and degenerated meniscus.

Risk factors and predictive models for early recurrent intussusception in children: a retrospective cohort study.

Background: Early recurrent intussusception (ERI) in children is common and seriously affects the physical and mental health of the children. There are few reports discussing risk factors for ERI in children, and this study aims to identify risk factors for ERI in children and build predictive models. Methods: We conducted a retrospective study of 787 children with no relapse intussusception (NRI) and 82 children with ERI between January 2011 and December 2021. Univariate and multifactorial stepwise logistic regression analysis was used to analyze the correlation between 11 factors and ERI, to determine the independent risk factors for ERI in children. The prediction model was established by independent risk factors and then verified. Results: Age, vomiting, bloody stools, and monocyte ratios were independently correlated with the composite endpoint (P<0.05). A nomogram was constructed and a calibration curve was plotted, using independent risk factors. Based on the disease's diagnostic score, the predictive model's performance was validated by using logistic regression receiver operating characteristic (ROC) curve detection, with area under the curve (AUC) value of 0.883 [95% confidence interval (CI): 0.846-0.920], and the calibration curve was close to the ideal diagonal line. In addition, the decision curve analysis (DCA) showed that the model had significant net benefits. Conclusions: Independent risk factors for ERI in children are age, vomiting, bloody stool, and monocyte ratio. Children older than 1 year in age, who lacked vomiting and bloody stool symptoms, and who exhibited an elevated ratio of monocytes were more likely to relapse early. The predictive model constructed herein can predict the early recurrence of children with ERI, providing a reference for clinicians' individualized judgments.

Lipid reprogramming induced by the NNMT-ABCA1 axis enhanced membrane fluidity to promote endometrial cancer progression.

Elucidating the mechanism for the high metastasis capacity of Endometrial cancer (EC) is crucial to improve treatment outcomes of EC. We have recently reported that nicotinamide N-methyltransferase (NNMT) is overexpressed in EC, especially in EC, and predicts poor survival of chemotherapy patients. Here, we aimed to determine the function and mechanism of NNMT on metastasis of EC. Additionally, analysis of public datasets indicated that NNMT is involved in cholesterol metabolism. In vitro, NNMT overexpression promoted migration and invasion of EC by reducing cholesterol levels in the cytoplasm and cell membrane. Mechanistically, NNMT activated ABCA1 expression, leading to cholesterol efflux and membrane fluidity enhancement, thereby promoting EC's epithelial-mesenchymal transition (EMT). In vivo, the metastasis capacity of EC was weakened by targeting NNMT. Our findings suggest a new molecular mechanism involving NNMT in metastasis, poor survival of EC mediated by PP2A and affecting cholesterol metabolism.

Diastereo- and Enantioselective Hydrophosphination of Cyclopropenes under Lanthanocene Catalysis.

The asymmetric hydrophosphination of cyclopropenes with phosphines is of much interest and importance, but has remained hardly explored to date probably because of the lack of suitable catalysts. We report here the diastereo- and enantioselective hydrophosphination of 3,3-disubstituted cyclopropenes with phosphines by a chiral lanthanocene catalyst bearing the C2 -symmetric 5,6-dioxy-4,7-trans-dialkyl-substituted tetrahydroindenyl ligands. This protocol offers a selective and efficient route for the synthesis of a new family of chiral phosphinocyclopropane derivatives, featuring 100 % atom efficiency, good diastereo- and enantioselectivity, broad substrate scope, and no need for a directing group.

Pharmacokinetics of Voriconazole in Peritoneal Fluid of Critically Ill Patients.

Data on the distribution of voriconazole (VRC) in the human peritoneal cavity are sparse. This prospective study aimed to describe the pharmacokinetics of intravenous VRC in the peritoneal fluid of critically ill patients. A total of 19 patients were included. Individual pharmacokinetic curves, drawn after single (first dose on day 1) and multiple (steady-state) doses, displayed a slower rise and lower fluctuation of VRC concentrations in peritoneal fluid than in plasma. Good but variable penetration of VRC into the peritoneal cavity was observed, and the median (range) peritoneal fluid/plasma ratios of the area under the concentration-time curve (AUC) were 0.54 (0.34 to 0.73) and 0.67 (0.63 to 0.94) for single and multiple doses, respectively. Approximately 81% (13/16) of the VRC steady-state trough concentrations (Cmin,ss) in plasma were within the therapeutic range (1 to 5.5 µg/mL), and the corresponding Cmin,ss (median [range]) in peritoneal fluid was 2.12 (1.39 to 3.72) µg/mL. Based on the recent 3-year (2019 to 2021) surveillance of the antifungal susceptibilities for Candida species isolated from peritoneal fluid in our center, the aforementioned 13 Cmin,ss in peritoneal fluid exceeded the MIC90 of C. albicans, C. glabrata, and C. parapsilosis (0.06, 1.00, and 0.25 µg/mL, respectively), which supported VRC as a reasonable choice for initial empirical therapies against intraabdominal candidiasis caused by these three Candida species, prior to the receipt of susceptibility testing results.

Population pharmacokinetics and limited sampling strategies of polymyxin B in critically ill patients.

OBJECTIVES: To characterize the pharmacokinetics (PK) of polymyxin B in Chinese critically ill patients. The factors significantly affecting PK parameters are identified, and a limited sampling strategy for therapeutic drug monitoring of polymyxin B is explored. METHODS: Thirty patients (212 samples) were included in a population PK analysis. A limited sampling strategy was developed using Bayesian estimation, multiple linear regression and modified integral equations. Non-linear mixed-effects models were developed using Phoenix NLME software. RESULTS: A two-compartment population PK model was used to describe polymyxin B PK. Population estimates of the volumes of central compartment distribution (V) and peripheral compartment distribution (V2), central compartment clearance (CL) and intercompartmental clearance (Q) were 7.857 L, 12.668 L, 1.672 L/h and 7.009 L/h. Continuous renal replacement therapy (CRRT) significantly affected CL, and body weight significantly affected CL and Q. The AUC0-12h of polymyxin B in patients with CRRT was significantly lower than in patients without CRRT. CL and Q increased with increasing body weight. A limited sampling strategy was suggested using a two-sample scheme with plasma at 0.5h and 8h after the end of infusion (C0.5 and C8) for therapeutic drug monitoring in the clinic. CONCLUSIONS: A dosing regimen should be based on body weight and the application of CRRT. A two-sample strategy for therapeutic drug monitoring could facilitate individualized treatment with polymyxin B in critically ill patients.

Risk factors for recurrence of gestational diabetes mellitus in southern Chinese women: a retrospective study.

OBJECTIVES: Predictors of gestational diabetes mellitus (GDM) recurrence (GDMR) was determined in southern Chinese women. MATERIAL AND METHODS: A total of 376 women with GDM who had two consecutive singleton deliveries at our hospital between January 2014 and October 2020 were enrolled in the current study. We retrospectively compared the clinical characteristics, fasting plasma glucose level (FPG-1), and oral glucose tolerance test-1h-1 and -2h-1 (OGTT 1hr-1: 1-h post-load glucose level during the first pregnancy and OGTT 2hr-1: 2-h post-load glucose level during the first pregnancy) for the first pregnancy between patients in the GDMR group (n = 166) and the non-GDMR group (n = 210). RESULTS: The incidence of GDMR in the study population was 44.15%. During the first pregnancy, women in the GDMR group had significantly higher OGTT 1h-1, OGTT 2h-1, and FPG-1 + OGTT 1h + 2h-1 compared to the non-GDMR group. When the threshold of the FPG-1 + OGTT 1h + 2h-1 level in the first pregnancy was > 23.6 mmol/L, the specificity for predicting GDMR was 0.85, the sensitivity was 0.45, and the area under the receiver operating characteristic curve (ROC-AUC) was 0.70, indicating a 70% probability of predicting GDMR in the next pregnancy. Logistic regression analysis showed that patients with a combined abnormal FPG-1 + OGTT 1h + 2 h-1 level had a 10-fold increased risk for GDMR in subsequent pregnancies than patients with normal indicators (OR: 10.542, 95% CI: 3.097-35.881; p < 0.0001). CONCLUSIONS: The OGTT 1h-1 and OGTT 2h-1 are independent risk factors for GDMR in southern Chinese women. Women with an FPG-1 + OGTT 1h + 2h-1 threshold level > 23.6 mmol/L in the first pregnancy had a 10-fold greater probability of developing GDMR in the second pregnancy than women in the non-GDMR group.

Tacrolimus pharmacokinetics in pediatric nephrotic syndrome: A combination of population pharmacokinetic modelling and machine learning approaches to improve individual prediction.

Background and Aim: Tacrolimus (TAC) is a first-line immunosuppressant for the treatment of refractory nephrotic syndrome (RNS), but the pharmacokinetics of TAC varies widely among individuals, and there is still no accurate model to predict the pharmacokinetics of TAC in RNS. Therefore, this study aimed to combine population pharmacokinetic (PPK) model and machine learning algorithms to develop a simple and accurate prediction model for TAC. Methods: 139 children with RNS from August 2013 to December 2018 were included, and blood samples of TAC trough and partial peak concentrations were collected. The blood concentration of TAC was determined by enzyme immunoassay; CYP3A5 was genotyped by polymerase chain reaction-restriction fragment length polymorphism method; MYH9, LAMB2, ACTN4 and other genotypes were determined by MALDI-TOF MS method; PPK model was established by nonlinear mixed-effects method. Based on this, six machine learning algorithms, including eXtreme Gradient Boosting (XGBoost), Random Forest (RF), Extra-Trees, Gradient Boosting Decision Tree (GBDT), Adaptive boosting (AdaBoost) and Lasso, were used to establish the machine learning model of TAC clearance. Results: A one-compartment model of first-order absorption and elimination adequately described the pharmacokinetics of TAC. Age, co-administration of Wuzhi capsules, CYP3A5 *3/*3 genotype and CTLA4 rs4553808 genotype were significantly affecting the clearance of TAC. Among the six machine learning models, the Lasso algorithm model performed the best (R2 = 0.42). Conclusion: For the first time, a clearance prediction model of TAC in pediatric patients with RNS was established using PPK combined with machine learning, by which the individual clearance of TAC can be predicted more accurately, and the initial dose of administration can be optimized to achieve the goal of individualized treatment.

Transverse testicular ectopia with persistent Mullerian duct syndrome: Report and review of two cases.

Transverse testicular ectopia is a rare anomaly characterized by both testes descending through a single inguinal canal. The objective of this study was to investigate the pathogenesis, diagnosis, and treatment of transverse testicular ectopia (TTE) with persistent Mullerian duct syndrome (PMDS), and to deepen the understanding of the disease in clinical. A retrospective analysis of the clinical manifestation, diagnosis, and treatment of two children suffering from TTE with PMDS was conducted. Previous studies on the characteristics, diagnosis, and treatment of this disease were reviewed. The two patients were treated with laparoscopy-assisted transseptal orchidopexy-inguinal evaluation. After the surgery, the two patients recovered well. The follow-up visits were done 3 months after the operation. An ultrasound examination confirmed that the two patients had testes in the orthotopic position and normal size. TTE with PMDS is an exceedingly rare disease. The patients manifested cryptorchidism on one side; contralateral inguinal hernia was suspected. Detailed physical and ultrasound examinations before the operation are the key to the early diagnosis of TTE. Laparoscopic evaluation is helpful for the diagnosis and finding of other abnormalities. Surgical treatment is the only method to cure the disease; long-term follow-up is needed after TTE operation.

The Nazeris fauna of the Leigong Mountain, Guizhou, China (Coleoptera, Staphylinidae, Paederinae).

Seven species of Nazeris Fauvel, 1873 are reported for Guizhou, China. All of them are described as new: N. ingentis Lin, Yu Hu, sp. n., N. resimus Lin, Yu Hu, sp. n., N. leigongensis Lin, Yu Hu, sp. n., N. yujiei Lin, Yu Hu, sp. n., N. muricatus Lin, Yu Hu, sp. n., N. excertus Lin, Yu Hu, sp. n. and N. serratus Lin, Yu Hu, sp. n.

A new species and additional records of Lobrathium Mulsant amp; Rey (Coleoptera: Staphylinidae: Paederinae) from southern China.

Lobrathium chengzhifeii Lin Peng sp. n. (Yunnan: Mengsong) is described and illustrated. The female sexual characters of L. anatinum W.-R. Li and L.-Z. Li, 2013 are described and illustrated for the first time. Additional records of L. ablectum Assing, 2012, L. biaculeatum Assing, 2012, L. demptum Assing, 2012, L. diaoluoense W.-R. Li and L.-Z. Li, 2013, L. excisissimum Assing, 2012, L. hongkongense Bernhauer, 1931 and L. tortile F.-K. Zheng, 1988 are reported. Including the new taxa, 66 Lobrathium species are currently known from China.

The neutrophil-to-lymphocyte ratio: A potential predictor of poor prognosis in adult patients with trauma and traumatic brain injury.

Purpose: This study aimed to determine the prognostic impact of the neutrophil-to-lymphocyte ratio (NLR) in critically ill trauma patients. Methods: This retrospective study involved adult trauma patients from 335 intensive care units (ICUs) at 208 hospitals stored in the eICU database. The primary outcome was ICU mortality. The lengths of ICU and hospital stay were calculated as the secondary outcomes. The multivariable logistic regression model was used to identify independent predictors of mortality. To identify the effect of the NLR on survival, a 15-day survival curve was used. Results: A total of 3,865 eligible subjects were enrolled in the study. Univariate analysis showed that patients in the group with a higher NLR were more likely to receive aggressive methods of care delivery: mechanical ventilation, vasopressor, and antibiotics ( P < 0.001 for all). The ICU, in-hospital, and 15-day mortality rates of the four groups increased in turn (P < 0.001 for all). The multivariable logistic Cox regression model indicated that a higher NLR was an independent risk factor of ICU mortality in trauma patients. ROC analysis showed that the NLR had better predictive capacity on the mortality of patients with traumatic brain injury (TBI) than those with trauma (AUC 0.725 vs. 0.681). An NLR > 7.44 was an independent risk factor for ICU death in patients with TBI (OR: 1.837, 95% CI: 1.045-3.229) and TBI victims whose NLR > 7.44 had a 15-day survival disadvantage (P = 0.005). Conclusion: A high NLR is associated with a poor prognosis in trauma patients, even worse in patients with TBI. An NLR > 7.44 is an independent risk factor for death in patients with TBI.

Organic chromium derived from the chelation of Ganoderma lucidum polysaccharide and chromium (III) alleviates metabolic syndromes and intestinal microbiota dysbiosis induced by high-fat and high-fructose diet.

Organic chromium is of great interest and has become an important chromium supplement resource in recent years because of its low toxicity and easy absorption. In our previous study, we synthesized a novel organic chromium [GLP-Cr] through the chelation of Ganoderma lucidum polysaccharide and chromium (III). The purpose of this study was to investigate the beneficial effects of GLP-Cr on the improvement of metabolic syndromes (MetS) in mice fed with a high-fat and high-fructose diet (HFHFD) and its mechanism of action. The results indicated that oral administration of GLP-Cr inhibited the excessive exaltation of body weight, glucose tolerance, fasting blood glucose and lipid levels, hepatic total cholesterol (TC), triglyceride (TG) levels caused by HFHFD. Besides, 16S rRNA amplicon sequencing showed that GLP-Cr intervention evidently ameliorated intestinal microbiota dysbiosis by changing the proportions of some intestinal microbial phylotypes. In addition, correlation network-based analysis indicated that the key intestinal microbial phylotypes were closely related to biochemical parameters associated with MetS under GLP-Cr intervention. Liver metabolomics analysis suggested that GLP-Cr intervention significantly regulated the levels of some biomarkers involved in alpha-linolenic acid metabolism, fatty acid biosynthesis, steroid hormone biosynthesis, glycerophospholipid metabolism, glycerolipid metabolism, steroid hormone biosynthesis, primary bile acid biosynthesis, and so on. Moreover, GLP-Cr intervention regulated liver mRNA levels of key genes associated with glucose and lipid metabolism. The mRNA level of glucose transporter type 4 (Glut4) was markedly increased by GLP-Cr intervention, and the mRNA levels of phosphoenolpyruvate carboxykinase (Pepck) and glucose-6-phosphatase (G6Pase) in the liver were significantly decreased. Meanwhile, GLP-Cr intervention significantly decreased hepatic mRNA levels of cluster of differentiation 36 (Cd36), acetyl-CoA carboxylase 1 (Acc1) and sterol regulatory element binding protein-1c (Srebp-1c), indicating that GLP-Cr intervention inhibited the excessive accumulation of free fatty acids in the liver. These findings suggest that the prevention of hyperglycemia and dyslipidemia by GLP-Cr may be closely related to the regulation of gut microbial composition and hepatic metabolic pathways, thus GLP-Cr can be serving as a functional component in the prevention of MetS.

Pregnant Populations which Benefit from Vaginal Progesterone for Preventing Preterm Birth at <34 Weeks and Neonatal Morbidities: A Systematic Review and Meta-analysis.

This study aimed to assess vaginal progesterone's effect on different populations and performed comparation between women with varied risk factors. Embase, PubMed, Cochrane library (CENTRAL) were searched without restriction to language up to February 25, 2021. Randomized controlled trials (RCTs) assessing vaginal progesterone administered to women at risk of preterm birth at <37 weeks. Two reviewers independently extracted data, and pooled relative risk (RR) with 95% confidence intervals (CIs) was calculated as well. Women with short cervix have a significantly lower risk of preterm birth at <34 weeks (pooled RR = 0.65; 95% CI: 0.55-0.77; I 2 = 0; p < 0.001; nine studies) and some neonatal morbidities; interaction tests showed that effect of vaginal progesterone differs significantly between women with short cervix and those with other risk factors (history of preterm birth, exclusive twin gestation, and vaginal bleeding). Evidences of this study showed that singleton gestations, as well as women with short cervix, benefit from vaginal progesterone in preventing preterm birth at <34 weeks and some neonatal morbidities. Women with short cervix are populations who benefit the most among other risk populations. KEY POINTS: · Vaginal progesterone reduces preterm birth and neonatal morbidities.. · Vaginal progesterone effects on some specific populations.. · Women with short cervix benefit the most..

New data on the genus Lathrobium Gravenhorst (Coleoptera: Staphylinidae: Paederinae) of Guangxi, South China.

Lathrobium caiyujiei Lin Peng sp. n. (Guangxi: Jinwanshan N. R.), L. jiuwanshanense Lin Peng sp. n. (Guangxi: Jinwanshan N. R.) and L. zhusha Lin Peng sp. n. (Guangxi: Jinwanshan N. R.) are described and illustrated. Additional records of L. damingense Peng Li, 2013, L. dayaoshanense Peng Li, 2012, L. hujiayaoi Peng Li, 2013, L. maoershanense Peng Li, 2012 and L. zhujianqingi Peng Li, 2012 are reported. Including the new taxa, 227 Lathrobium species are currently known from mainland China.

Evaluation of quality and readability of over-the-counter medication package inserts.

BACKGROUND: Over-the-counter (OTC) medication package inserts are vital references for healthcare professionals to make drug recommendations and influential education materials that patients commonly refer to when self-caring. However, little is known about the quality and readability of the OTC medication package inserts in China. OBJECTIVES: This study aimed at evaluating the quality and readability of OTC medication package inserts. METHODS: Package inserts of OTC medication were selected based on the market share and pharmacological category. The quality of the package inserts was evaluated based on standards adapted separately from the Chinese National Medical Products Administration (NMPA) and European Medicines Agency's (EMA) Working Group. The readability was assessed using the Patient Education Materials Assessment Tool (PEMAT) in conjunction with the Chinese Readability Index Explorer (CRIE). RESULTS: A total of 29 OTC medication package inserts consisting of 12 Western Medicine (WM) and 17 Chinese Tradition Patent Medicine (CTPM) package inserts were included. Overall, the OTC package inserts met 92% of the NMPA standards and 54% of the EMA standards. In terms of readability assessment using PEMAT, the overall median (interquartile range) understandability score was 38% (38-45%) and for actionability score was 40% (40-55%). The overall text reading level of package inserts measured by the CRIE, after removing some medical jargon, is equivalent to the median reading level for the 12th (9.5-12th) grade reading level. CONCLUSIONS: The quality of OTC medication package inserts was satisfactory under internal standards but poor under international standards. Some OTC pharmacological information is not provided due to lack of research, especially for CTPM. A more informative and comprehensive package insert may be needed to guide drug use decisions. OTC medication package inserts are not appropriate patient education materials in terms of readability. Additional materials may be developed to supplement package inserts for patient education for OTC medications.

Asymmetric Catalytic (2+1) Cycloaddition of Thioketones to Synthesize Tetrasubstituted Thiiranes.

Herein, we report the first example of enantioselective (2+1) cycloaddition of thioketones with α-diazo pyrazoleamides for the direct synthesis of tetrasubstituted thiiranes. In the presence of chiral N,N'-dioxide/cobalt(ΙΙ) complexes (2-5 mol%), excellent efficiency (up to 99 % yield within 15 mins) and high stereoselectivity (up to >19 : 1 dr and 97 % ee) are available. Elaborations of thiiranes via desulfuration have also been conducted to deliver tetrasubstituted olefins. Density functional theory calculations reveal that the reaction initiates from a doublet state cobalt(ΙΙ) carbenoid, which is followed by a quartet cobalt(ΙΙ)-bound thiocarbonyl ylide pathway. This work provides a route for the selective construction of tetrasubstituted thiiranes and olefins that are otherwise difficult to access.