Netrin-1 induces the anti-apoptotic and pro-survival effects of B-ALL cells through the Unc5b-MAPK axis.

BACKGROUND: B-cell acute lymphoblastic leukemia (B-ALL) comprises over 85% of all acute lymphoblastic leukemia (ALL) cases and is the most common childhood malignancy. Although the 5 year overall survival of patients with B-ALL exceeds 90%, patients with relapsed or refractory B-ALL may suffer from poor prognosis and adverse events. The axon guidance factor netrin-1 has been reported to be involved in the tumorigenesis of many types of cancers. However, the impact of netrin-1 on B-ALL remains unknown. METHODS: The expression level of netrin-1 in peripheral blood samples of children with B-ALL and children without neoplasia was measured by enzyme-linked immunosorbent assay (ELISA) kits. Then, CCK-8 cell proliferation assays and flow cytometric analysis were performed to detect the viability and apoptosis of B-ALL cells (Reh and Sup B15) treated with exogenous recombinant netrin-1 at concentrations of 0, 25, 50, and 100 ng/ml. Furthermore, co-immunoprecipitation(co-IP) was performed to detect the receptor of netrin-1. UNC5B expression interference was induced in B-ALL cells with recombinant lentivirus, and then CCK-8 assays, flow cytometry assays and western blotting assays were performed to verify that netrin-1 might act on B-ALL cells via the receptor Unc5b. Finally, western blotting and kinase inhibitor treatment were applied to detect the downstream signaling pathway. RESULTS: Netrin-1 expression was increased in B-ALL, and netrin-1 expression was upregulated in patients with high- and intermediate-risk stratification group of patients. Then, we found that netrin-1 induced an anti-apoptotic effect in B-ALL cells, implying that netrin-1 plays an oncogenic role in B-ALL. co-IP results showed that netrin-1 interacted with the receptor Unc5b in B-ALL cells. Interference with UNC5B was performed in B-ALL cells and abolished the antiapoptotic effects of netrin-1. Further western blotting was applied to detect the phosphorylation levels of key molecules in common signaling transduction pathways in B-ALL cells treated with recombinant netrin-1, and the FAK-MAPK signaling pathway was found to be activated. The anti-apoptotic effect of netrin-1 and FAK-MAPK phosphorylation was abrogated by UNC5B interference. FAK inhibitor treatment and ERK inhibitor treatment were applied and verified that the FAK-MAPK pathway may be downstream of Unc5b. CONCLUSION: Taken together, our findings suggested that netrin-1 induced the anti-apoptotic effect of B-ALL cells through activation of the FAK-MAPK signaling pathway by binding to the receptor Unc5b. Video Abstract.

Effects of decompressive operation on cardiac autonomic regulation in patients with cervical spondylotic myelopathy: analysis of blood pressure, heart rate, and heart rate variability.

PURPOSE: To investigate the effects of cervical decompression operation on cardiac autonomic regulation and its relationship to recovery of somatic neurological function in cervical spondylotic myelopathy (CSM) patients. METHODS: One hundred and thirty-two consecutive patients were enrolled in this study, in which 73 patients received decompression operation and the remaining 59 were treated non-operatively. The follow-up period was 6 months. Baseline and follow-up evaluation included Japanese Orthopaedic Association (JOA) score, office-based blood pressure (BP) measurement, heart rate (HR), and 24-h heart rate variability (HRV) assessment. Relationship between achieved JOA score (final JOA score-baseline score) and changes of BP, HR, and HRV parameters in both operative and non-operative groups was analyzed. RESULTS: In operative group, patients' JOA score and markers of parasympathetic activity in HRV assessment were significantly higher than baseline level 6 months later. Blood pressure, especially systolic blood pressure (SBP), was significantly downregulated in both hypertension and non-hypertension patients. Mean heart rate was also significantly decreased. Furthermore, achieved JOA score was significantly negatively correlated with changes of SBP, minimal HR, mean HR, maximum HR, but significantly positively correlated with changes of HRV parameters reflecting parasympathetic activity. However, changes of JOA score, BP, HR, and HRV parameters in non-operative group were not significant. CONCLUSIONS: Cervical decompression operation could improve both somatic neurological function and cardiac autonomic regulation in CSM patients, and achieved JOA score was significantly positively correlated with improvement in HRV and cardiac parasympathetic activity. These slides can be retrieved under Electronic Supplementary Material.

Ultrahigh surface area zirconium MOFs and insights into the applicability of the BET theory.

An isoreticular series of metal-organic frameworks (MOFs) with the ftw topology based on zirconium oxoclusters and tetracarboxylate linkers with a planar core (NU-1101 through NU-1104) has been synthesized employing a linker expansion approach. In this series, NU-1103 has a pore volume of 2.91 cc g(-1) and a geometrically calculated surface area of 5646 m(2) g(-1), which is the highest value reported to date for a zirconium-based MOF and among the largest that have been reported for any porous material. Successful activation of the MOFs was proven based on the agreement of pore volumes and BET areas obtained from simulated and experimental isotherms. Critical for practical applications, NU-1103 combines for the first time ultrahigh surface area and water stability, where this material retained complete structural integrity after soaking in water. Pressure range selection for the BET calculations on these materials was guided by the four so-called "consistency criteria". The experimental BET area of NU-1103 was 6550 m(2) g(-1). Insights obtained from molecular simulation suggest that, as a consequence of pore-filling contamination, the BET method overestimates the monolayer loading of NU-1103 by ∼16%.

Multiobjective Evolutionary Learning for Multitask Quality Prediction Problems in Continuous Annealing Process.

In industrial production processes, the mechanical properties of materials will directly determine the stability and consistency of product quality. However, detecting the current mechanical property is time-consuming and labor-intensive, and the material quality cannot be controlled in time. To achieve high-quality steel materials, developing a novel intelligent manufacturing technology that can satisfy multitask predictions for material properties has become a new research trend. This article proposes a multiobjective evolutionary learning method based on a two-stage model with topological sparse autoencoder (TSAE) and ensemble learning. For the structure characteristics of a typical autoencoder (AE), a topology-related constraint is incorporated into the loss function of the AE, thus maintaining the global relationship among multistage input data to improve the data reconstruction quality. Then, a sparse representation of the data is added to the AE to achieve dimensionality reduction. Moreover, the extreme gradient boosting (XGBoost) method is applied to predict the mechanical properties of steel materials through collaboration learning mechanisms. To enhance the model accuracy, a multiobjective evolutionary algorithm (MOEA) with a knee solution strategy is used to optimize the network structure and hyperparameters of the two-stage model. Experiments are conducted using real steel production data from a continuous annealing process (CAP). The results verify that the proposed method obtains a higher prediction accuracy than other state-of-the-art methods and can guide practical production and new material design.

Effects of mind-body exercise on cognitive performance in middle-aged and older adults with mild cognitive impairment: A meta-analysis study.

BACKGROUND: To systematically evaluate the clinical efficacy of physical and mental exercise on cognitive performance in middle-aged people with mild cognitive impairment (MCI). METHODS: Computer searches of PubMed, Web of science, Embase, Cochrane Library, China Biomedical Literature Service, Wanfang database, China Knowledge Network, and VIP full-text database of Veep journals were conducted to obtain clinical randomized controlled trials on physical and mental exercise interventions in middle-aged and elderly people with MCI. The literature was screened according to inclusion and exclusion criteria, and the final included literature was subjected to data extraction and risk of bias assessment. Meta-analysis was performed using Review Manager 5.4.1 software, and publication bias test was performed using stata17.0 software. RESULTS: A total of 27 publications with a total of 2565 cases of elderly people with MCI were included. The control group was conventional care, health education, or blank control, and the physical and mental exercise group was exercises including Tai Chi, dance, orthopraxia, and qigong for 30 to 90 minutes each time, 3 to 6 times per week, for a total duration of 8 to 36 weeks. Meta-analysis results showed that Montreal cognitive assessment scores (mean difference [MD] = 2.33, 95% CI [1.55, 3.10], P < .00001), the mini-mental state examination score (MD = 1.73, 95% CI [0.60, 2.86], P = .003), trail making test-A score (MD = -4.00, 95% CI [-6.75, -1.25], P = .004), trail making test-B score (MD = -18.46, 95% CI [-23.87, -13.06], P < .00001), global deterioration scale score (MD = -0.72, 95% CI [-1.09, -0.34], P = .0002), Wechsler Logical Memory Scale score (MD = 2.07, 95% CI [0.03, 4.10], P = .05), berg score (MD = -0.70, 95% CI [0.32, 1.07], P < .0003), cerebrospinal fluid Tau protein level (MD = -166.69, 95% CI [-196.93, -136.45], P < .00001), and cerebrospinal fluid levels of αß1-42 protein (MD = 180.39, 95% CI [134.24, 226.55], P < .00001). CONCLUSION: Mind-body exercise can improve cognitive performance, depressive status, and balance as well as increase αß1-42 protein levels and decrease Tau protein levels in middle-aged and older adults with mild cognitive impairment.

Subcutaneous infection mouse model could be applied into real time monitoring the efficacy of anti-cystic echinococcosis drug in vivo.

Cystic echinococcosis (CE) is a zoonotic parasitic disease with a cosmopolitan distribution, and it is urgent to develop novel anti-helminthic agents. The intraperitoneal (ip) infection mice model was widely used to evaluate the efficacy of potential anti-CE compounds. Still, it's time-consuming, and the inability to achieve real-time monitoring hinders the development of potential anti-CE compounds. In this study, a CE mouse model was established by subcutaneous (sc) injection of protoscoleces of Echinococcus granulosus sensu stricto (E.granulosus s.s.) and used to assess the efficiency and efficacy of prospective anti-CE drugs. Compared to the ip infection CE mice model, the lesion volume of sc infection protoscoleces of E.granulosus s.s. (EgPSCs) could be measured by vernier caliper at week 6 post-infection. In contrast, the lesion volume of ip infection CE mice model was detected by ultrasound-assisted diagnosis at week 16 post-infection. Oral administration of albendazole (ABZ) could reduce cystic weight by 32.17% and 17.61%, the cystic number by 12.24% and 25.19%, and damage the ultrastructure of the cysts of E. granulosus s.s. in the sc and ip infection group, respectively. Furthermore, we found that the sc infection mice model could real-time monitor the lesion volume of E. granulosus s.s. during the ABZ and everolimus treatment. Therefore, we consider that the sc infection CE mice model is an assistant tool for screening and developing potential anti-CE compounds.

Netrin-1 inducing antiapoptotic effect of acute myeloid leukemia cells in a concentration-dependent manner through the Unc-5 netrin receptor B-focal adhesion kinase axis.

Acute myeloid leukemia (AML) is a hematological malignancy that commonly occurs in children. The prognosis of pediatric AML is relatively poor, thus threatening the patient's survival. The aberrant expression of the axon guidance factor, netrin-1, is observed in various types of malignancies, and it participates in the proliferation and apoptosis of tumor cells. Herein, we aimed to explore the role of netrin-1 in AML cells. Netrin-1 is highly expressed in AML patients. Proliferation and anti-apoptosis were observed in AML cells treated with netrin-1. The interaction between netrin-1 and Unc-5 netrin receptor B (UNC5B) was detected through coimmunoprecipitation, and UNC5B ribonucleic acid interference restrained the influence of netrin-1 on the AML cells. The phosphorylation of focal adhesion kinase-protein kinase B (FAK-Akt) was upregulated in AML cells treated with netrin-1. Both FAK and Akt inhibitors abrogated the effects of netrin-1 on the proliferation and apoptosis of AML cells. In conclusion, netrin-1 could promote the growth and reduce the apoptosis of AML cells in a concentration-dependent manner, and that these effects were mediated by activating the FAK-Akt signaling pathway via the UNC5B.

An expeditious route to eight-membered heterocycles by nickel-catalyzed cycloaddition: low-temperature C(sp)2-C(sp)3 bond cleavage.

A cool break: 3-Azetidinone and a variety of diynes undergo a cycloaddition reaction catalyzed by Ni/IPr to give dihydroazocine compounds (see scheme; IPr=1,3-bis(2,6-diisopropylphenyl)imidazolidene). The reaction involves a challenging C(sp)2-C(sp)3 bond cleavage step, yet, surprisingly, proceeds at low temperature.

Upregulated TUBG1 expression is correlated with poor prognosis in hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) development is a complex pathological process. Tubulin gamma 1 (TUBG1) plays an oncogenic role in several human cancers; however, its functional role in HCC tumorigenesis remains unknown. Methods: Herein we first evaluated the gene expression levels of TUBG1 in HCC using data from The Cancer Genome Atlas and Gene Expression Profiling Interactive Analysis databases. We then elucidated the association between TUBG1 gene expression levels and survival rates of patients with HCC. Cell cycle, proliferation, transwell migration, and matrigel invasion assays were used to study the effects of TUBG1 on the malignant phenotypes of HCC cells. Results: Based on the data obtained from the aforementioned databases and our in vitro experiments, TUBG1 was found to be overexpressed in HCC and patients with high TUBG1 expression levels showed a remarkably poor overall survival rate. In addition, the expression of TUBG1 significantly promoted the malignant phenotypes of HCC cells in vitro. Gene ontology term enrichment analysis revealed that co-regulated genes were enriched in biological processes mainly involved in chromosome segregation, chromosomal region, and chromatin binding; moreover, Kyoto Encyclopedia of Genes and Genome pathway analysis showed that they were mainly involved in cell cycle, oocyte meiosis, platinum drug resistance, and the p53 signaling pathway. Conclusions: We report that TUBG1 is an important oncogene in HCC. It promotes HCC progression and may serve as a potential prognostic biomarker for HCC. Future studies are warranted to unveil molecular biological mechanisms underlying TUBG1 carcinogenesis.

[Effect of Netrin-1 on VEGFA Expression in T-ALL Cells and Its Related Mechanism].

AbstractObjective: To investigate the effect of the axon guidance factor Netrin-1 on the expression of VEGFA in T cell acute lymphoblastic leukemia(T-ALL) and its related mechanism. METHODS: ELISA assays were applied to detect the levels of Netrin-1 and VEGFA in the bone marrow (BM) samples from children in the T-ALL and control group. The level of Netrin-1 and VEGFA were compared between control children and patients, and the liner correlation between Netrin-1 and VEGFA was analyzed. The T-ALL cells Jurkat and Molt-4 were culture in vitro, and the cells were treated with different concentration of Netrin-1 (0, 25, 50, 100 ng/ml) for 24 h, quantitative RT-PCR (qRT-PCR) and Western blot were used to detect the VEGFA expression in Jurkat, Molt-4 cells. The expression of Netrin-1 receptors in T-ALL cells was detected by qRT-PCR and the interaction between Netrin-1 and receptor in each cells was detected by co-IP. Furthermore, Western blot was used to detect the phosphorylation level of key prateins of AKT signal transduction pathway including Akt and mTOR in T-ALL cells treated with Netrin-1 (100 ng/ml). The expression of VEGFA and phosphorylation of AKT pathway transducers were detected by Western blot, after T-ALL cells treated with Netrin-1 (100 ng/ml) combined with inhibitors specific to Akt or mTOR. RESULTS: The expression level of Netrin-1 and VEGFA in T-ALL patients BM samples were both signi-ficantly higher than that of control group. And the expression level of Netrin-1 was positively correlated with that of VEGFA（r2=0974). With the increase of Netrin-1 concentration, the expression level of VEGFA also increased(P<0.05）. Netrin-1 interacted with its receptor, integrin-ß4 at the Netrin-1 concentration of 100 ng/ml. Further, the treatment of Netrin-1 could increase the phosphorylation of Akt and mTOR, which were the key transducers of AKT pathway. After treatment of T-ALL cells with Netrin-1 (100 ng/mL) and Akt inhibitor, the expression of VEGFA and phosphorylation of Akt or mTOR decreased. When the cells were treated with Netrin-1(100 ng/ml) and mTOR inbititor, the phosphorylation level of mTOR and the expression of VEGFA decreased, the phosphorylation level of Akt increased. CONCLUSION: The expression of Netrin-1 and VEGFA in bone marrow of childred with T-ALL were abnormal, and there was a linear relationship between them. Netrin-1 can interact with its receptor, integrin-ß4 and activate AKT transduction pathway to elevate the expression of VEGFA in T-ALL cells.

Type O blood, the MCHC, and the reticulocyte count impact the early recurrence of primary warm-antibody autoimmune hemolytic anemia in children: A retrospective cohort analysis.

Objective: Primary warm-antibody autoimmune hemolytic anemia (w-AIHA) is prone to recurrence in children. In this study, we aimed to identify risk indicators for the early recurrence of primary w-AIHA and construct an effective recurrence risk assessment model. Methods: This was a retrospective cohort study. The clinical data of patients hospitalized with primary w-AIHA in the Department of Hematology and Oncology, Children's Hospital of Chongqing Medical University, between 1 January 2018 and 30 September 2021, were collected at the initial diagnosis. Univariate and multivariate logistic regression analyses were used to determine risk indicators for the early recurrence of primary w-AIHA in children, and ROC curve and Kaplan-Meier survival analyses were used for verification. Finally, a risk assessment model for early recurrence in children with primary w-AIHA was constructed using Cox regression and visualized using a nomogram. The model was also verified internally and externally. Results: This study included 62 children with primary w-AIHA. Of which, 18 experienced recurrence 1 year after the initial diagnosis. The univariate and multivariate logistic regression analyses showed that type O blood and the reticulocyte count (Ret) were risk indicators for the early recurrence of pediatric primary w-AIHA (P = 0.009, 0.047, respectively). The mean corpuscular hemoglobin concentration (MCHC) is a protective factor (P = 0.040). According to the ROC curve and Kaplan-Meier survival analyses, children with primary w-AIHA whose blood type was O or had an MCHC of <313.5 pg/fL or a Ret of ≥0.161×1012/L had a higher risk of early recurrence (HR = 2.640, 4.430 and 4.450, respectively, and P = 0.040, 0.015 and 0.018, respectively). The blood types (O), MCHCs, and Rets of 56 patients were incorporated into the Cox regression model, and the recurrence risk assessment model for children with primary w-AIHA was successfully constructed and visualized using a nomogram. The calibration curves and decision-curve analysis (DCA) suggested that the risk model has clinical applicability and effectiveness. Conclusion: Children with type O blood and an MCHC value of <313.5 pg/fL or a Ret value of ≥0.161×1012/L have a higher risk of early recurrence. The risk assessment model for the early recurrence of pediatric primary w-AIHA constructed in this study has good clinical applicability and effectiveness.

Rhodium-catalyzed decarboxylative cycloaddition route to substituted anilines.

A convenient method for preparing substituted anilines via a Rh-catalyzed [2 + 2 + 2] cycloaddition reaction of diynes and 2-oxazolone was discovered. The initial cycloaddition adducts undergo facile decarboxylation of carbon dioxide to afford aniline products. Reaction conditions are mild, and only 3 mol % Rh catalyst is required. High regioselectivity was observed when an unsymmetrical diyne was used as a starting material.

Lymphocyte cytosolic protein 2 is a novel prognostic marker in lung adenocarcinoma.

OBJECTIVE: Lymphocyte cytosolic protein 2 (LCP2) is often ectopically expressed in various human tumors. However, the clinical significance and role of LCP2 in lung adenocarcinoma (LUAD) remain unclear. This study explored the prognostic significance of LCP2 in LUAD patients. METHODS: LCP2 expression in LUAD tissues was analyzed using data from The Cancer Genome Atlas and Genotype-Tissue Expression databases. Western blotting was employed to detect LCP2 expression in LUAD. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to explore signaling pathways mediated by LCP2 co-regulatory genes. Immunohistochemistry was used to examine levels of LCP2 and programmed death ligand 1 (PD-L1) in 68 LUAD patients. Associations between LCP2 expression and clinicopathological features, prognoses, and PD-L1 levels among the LUAD in-patients were analyzed. RESULTS: Among the 68 LUAD in-patients, LCP2 expression was correlated with clinical stage and lymph node metastasis. LUAD patients with high LCP2 expression were associated with increased overall survival. LCP2 expression may be associated with an enrichment of several immune functions. Moreover, our immunohistochemistry results demonstrated that LCP2 expression was positively correlated with PD-L1 expression in LUAD tissues. CONCLUSIONS: In the study, LCP2 was found to be a favorable prognostic biomarker in LUAD patients.

Upregulated LINC01667 Expression Is Correlated With Poor Prognosis in Hepatocellular Carcinoma.

The development of hepatocellular carcinoma (HCC) is a complex pathological process. Long intergenic non-protein-coding RNA 1667 (LINC01667, also known as MGC38584) plays an oncogenic role in several human cancers; however, its functional role in HCC tumorigenesis remains unknown. Here, we first evaluated the gene expression levels of LINC01667 in HCC using data from The Cancer Genome Atlas and Gene Expression Profiling Interactive Analysis (GEPIA) databases. We then elucidated the association between LINC01667 gene expression levels and the survival rates of patients with HCC. We detected the effect of LINC01667 on the malignant phenotypes (cell proliferation, migration, invasion and apoptosis etc.) and the MAPK and PI3K/AKT/mTOR signaling pathways of HepG2, SMMC-7721 and HUH7 cells. We also analyzed the sensitivity of HepG2, SMMC-7721 and HUH7 with different expression levels of LINC01667 to anti-HCC drugs in vitro. Based on data from the aforementioned databases and our experiments in vitro, we found that LINC01667 was overexpressed in HCC, and that patients with high LINC01667 levels had a remarkably poor overall survival rate. In addition, inhibition of LINC01667 expression suppressed the proliferation, migration and invasion of HepG2 and SMMC-7721 cells and promoted their apoptosis in vitro. In contrast, overexpression of LINC01667 promoted the proliferation, migration and invasion of HUH7 cells and suppressed their apoptosis in vitro. ChIRP-seq (chromatin isolation by RNA purification) showed that LINC01667 bound to MEG3, and downregulated the expression of MEG3. In addition, western blotting showed that LINC01667 could activate the NF-κB pathway to promote cancer progression. In conclusion, we report that LINC01667 is an important oncogene in HCC and may be used as a potential diagnostic and prognostic biomarker of HCC.

Corrigendum: Upregulated LINC01667 Expression Is Correlated With Poor Prognosis in Hepatocellular Carcinoma.

[This corrects the article DOI: 10.3389/fonc.2021.650173.].

Increased SPHK1 and HAS2 Expressions Correlate to Poor Prognosis in Pancreatic Cancer.

OBJECTIVE: SPHK1 and HAS2 have been reported to play important roles in tumorigenesis and development. However, their expression and prognostic value in pancreatic cancer (PC) remain unclear. This study is aimed at investigating the expression of SPHK1 and HAS2 on the prognosis of pancreatic cancer. MATERIALS AND METHODS: The expression of SPHK1 and HAS2 in pancreatic cancer tissues was analyzed through TCGA and GTEx databases and validated by qRT-PCR and Western blot in pancreatic cancer cell lines. χ 2 test was used to explore the correlation of the SPHK1 and HAS2 expressions with clinical characteristics. Kaplan-Meier survival analysis and ROC curve were used to evaluate the prognostic and diagnostic roles of SPHK1 and HAS2 in pancreatic cancer. Additionally, Spearman correlation analysis was applied to assess the correlation between the SPHK1 and HAS2 in pancreatic cancer. GO analysis and KEGG analysis were applied to explore the possible signaling pathway that SPHK1 and HAS2 coregulated genes mediated. RESULTS: The expression of SPHK1 and HAS2 was markedly upregulated in pancreatic cancer tissue and cell lines, respectively. Furthermore, there was a significant positive correlation between SPHK1 and HAS2 expressions. ROC curves showed that SPHK1 combine with HAS2 has good diagnostic value in pancreatic cancer patients with 85% sensitivity and 99.4% specificity. Kaplan-Meier analysis showed that increased expression of SPHK1 and HAS2 was significantly associated with short overall survival (OS) of pancreatic cancer patients. GO and KEGG results revealed that SPHK1 and HAS2 mainly involved cell proliferation and invasion mediated by extracellular matrix- (ECM-) receptor interaction, focal adhesion, and PI3K-AKT signaling pathways. CONCLUSIONS: Overexpression of SPHK1 and HAS2 could be important markers for the prognosis of pancreatic cancer.

Coupling of Vinyl Aziridines and Isocyanates.

Thermal coupling of vinyl aziridines and phenyl isocyanate was evaluated. Although oxazolidinone products were predominant, some reactions afforded a seven-membered ring heterocycle. When Ni/IMes was employed as a catalyst, a wider array of vinyl aziridines underwent coupling reactions. The Ni catalyzed reactions generally afforded vinyl imidazolidinones as major products.

Nickel-catalyzed reactions of vinyl aziridines and aziridinylen-ynes.

Ni/NHC was found to catalyze the rearrangement of vinyl aziridines and aziridinylen-ynes under mild conditions.

Liquid-Phase Epitaxially Grown Metal-Organic Framework Thin Films for Efficient Tandem Catalysis Through Site-Isolation of Catalytic Centers.

A functional metal-organic framework (MOF) composed of robust porphyrinic material (RPM) based on the pillared-paddlewheel topology is prepared with large 3 D channels, and is used to perform a tandem epoxidation/CO2 insertion reaction. The designated system benefits from two metalloporphyrins: 1) a Mn-porphyrin, which catalyzes the epoxidation of an olefin substrate, and 2) a Zn-porphyrin, which catalyzes the epoxide opening. By using an automated liquid-phase epitaxial growth system, the RPM-MOF is also prepared in layer-by-layer fashion as an ultrathin film on a self-assembled-monolayer-coated silicon platform. Deployed as a tandem catalyst, the film version yields a substantially higher catalytic turnover number for tandem methoxy-styrene epoxidation followed by CO2 insertion than the bulk crystalline MOF samples.

Stable and catalytically active iron porphyrin-based porous organic polymer: Activity as both a redox and Lewis acid catalyst.

A new porphyrin-based porous organic polymer (POP) with BET surface area ranging from 780 to 880 m(2)/g was synthesized in free-base form via the reaction of meso-tetrakis(pentafluorophenyl) porphyrin and a rigid trigonal building block, hexahydroxytriphenylene. The material was then metallated with Fe(III) imparting activity for Lewis acid catalysis (regioselective methanolysis ring-opening of styrene oxide), oxidative cyclization catalysis (conversion of bis(2-hydroxy-1-naphthyl)methanes to the corresponding spirodienone), and a tandem catalytic processes: an in situ oxidation-cyclic aminal formation-oxidation sequence, which selectively converts benzyl alcohol to 2-phenyl-quinazolin-4(3H)-one. Notably, the catalyst is readily recoverable and reusable, with little loss in catalytic activity.