Visible light-induced chemoselective 1,2-diheteroarylation of alkenes.

Visible-light photocatalysis has evolved as a powerful technique to enable controllable radical reactions. Exploring unique photocatalytic mode for obtaining new chemoselectivity and product diversity is of great significance. Herein, we present a photo-induced chemoselective 1,2-diheteroarylation of unactivated alkenes utilizing halopyridines and quinolines. The ring-fused azaarenes serve as not only substrate, but also potential precursors for halogen-atom abstraction for pyridyl radical generation in this photocatalysis. As a complement to metal catalysis, this photo-induced radical process with mild and redox neutral conditions assembles two different heteroaryl groups into alkenes regioselectively and contribute to broad substrates scope. The obtained products containing aza-arene units permit various further diversifications, demonstrating the synthetic utility of this protocol. We anticipate that this protocol will trigger the further advancement of photo-induced alkyl/aryl halides activation.

Construction of Bridged Benzazepines via Photo-Induced Dearomatization.

Bridged benzazepine scaffolds, possessing unique structural and physicochemical activities, are widespread in various natural products and drugs. The construction of these skeletons often requires elaborate synthetic effort with low efficiency. Herein, we develop a simple and divergent approach for constructing various bridged benzazepines by a photocatalytic intermolecular dearomatization of naphthalene derivatives with readily available α-amino acids. The bridged motif is created via a cascade sequence involving photocatalytic 1,4-hydroaminoalkylation, alkene isomerization and cyclization. Interestingly, the diastereoselectivity can be regulated through different reaction modes in the cyclization step. Moreover, aminohydroxylation and its further bromination have also been demonstrated to access highly functionalized bridged benzazepines. Preliminary mechanistic studies have been performed to get insights into the mechanism. This method provides a divergent synthetic approach for construction of highly functionalized bridged benzazepines, which have been otherwise difficult to access.

Hydrated [3+2] Cyclotelomerization of Butafulvenes to Create Multiple Contiguous Fully Substituted Carbon Centers.

The construction of multiple continuous fully substituted carbon centers, which serve as unique structural motif in natural products, is a challenging topic in organic synthesis. Herein, we report a hydrated [3+2] cyclotelomerization of butafulvenes to create contiguous fully substituted carbon backbone. In the presence of scandium triflate, all-carbon skeleton with spiro fused tricyclic ring can be constructed in high diastereoselectivity by utilizing butafulvene as the synthon. Mechanistic studies suggest that this atom-economic reaction probably proceeds through a synergistic process containing butafulvenes dimerization and nucleophilic attack by water. In addition, the tricyclic product can undergo a series of synthetic derivatizations, which highlights the potential applications of this strategy. The recyclability of Sc(OTf)3 has also been demonstrated to show its robust performance in this hydrated cyclotelomerization.

Photo-induced imino functionalizations of alkenes via intermolecular charge transfer.

A catalyst-free photosensitized strategy has been developed for regioselective imino functionalizations of alkenes via the formation of an EDA complex. This photo-induced protocol facilitates the construction of structurally diverse ß-imino sulfones and vinyl sulfones in moderate to high yields. Mechanistic studies reveal that the reaction is initiated with an intermolecular charge transfer between oximes and sulfinates, followed by fragmentation to generate a persistent iminyl radical and transient sulfonyl radical. This catalyst-free protocol also features excellent regioselectivity, broad functional group tolerance and mild reaction conditions. The late stage functionalization of natural product derived compounds and total synthesis of some bioactive molecules have been demonstrated to highlight the utility of this protocol. Meanwhile, the compatibility of different donors has proved the generality of this strategy.

Palladium-catalysed construction of butafulvenes.

Butafulvene is a constitutional isomer of benzene, comprising a cyclobutene skeleton bearing two exocyclic conjugated methylene units. As a result of the intrinsic high strain energy and anti-aromaticity, the preparation of butafulvene compounds has been a fundamental issue for the development of butafulvene chemistry. Here an efficient palladium-catalysed coupling protocol involving propargylic compounds has been developed, providing a solid and versatile strategy for the rapid assembly of symmetric butafulvene derivatives. Based on mechanistic studies, two complementary mechanisms, both involving palladium catalysis, have been confirmed. With the mechanism unveiled, the synthesis of non-symmetric butafulvenes has also been achieved. Advantages of this strategy include tolerance to a wide range of propargylic molecules, mild reaction conditions, simple catalytic systems and easy scalability. The synthetic potential of the products as platform molecules for cyclobutene derivatives has also been demonstrated.

Rhodium-Catalyzed Deuterated Tsuji-Wilkinson Decarbonylation of Aldehydes with Deuterium Oxide.

The recent surge in the applications of deuterated drug candidates has rendered an urgent need for diverse deuterium labeling techniques. Herein, an efficient Rh-catalyzed deuterated Tsuji-Wilkinson decarbonylation of naturally available aldehydes with D2O is developed. In this reaction, D2O not only acts as a deuterated reagent and solvent but also promotes Rh-catalyzed decarbonylation. In addition, decarbonylative strategies for the synthesis of terminal monodeuterated alkenes from α,ß-unsaturated aldehydes are within reach.

The effect of percutaneous drainage using tiny incisions on the inflammatory factors in chronic venous insufficiency combined with lipodermatosclerosis of the lower extremities.

OBJECTIVE: To explore the efficacy of percutaneous drainage with tiny incisions in chronic venous insufficiency (CVI) combined with lipodystrophy syndrome (LDS) of the lower extremities and its effect on the inflammatory factors. METHODS: Sixty patients with CVI and LDS hospitalized for surgical treatment in Jiading District Central Hospital were recruited as the study cohort and randomly divided into a control group and an experimental group. The control group (n = 30) underwent varicose vein stripping in the lower extremities, while the experimental group (n = 30) was additionally treated with percutaneous drainage with tiny incisions for LDS. The efficacy of the two treatments, the mRNA expressions of collagen type I alpha 1 chain 1 (COL1A1), the lower limb circumferences, the subcutaneous thicknesses, the transcutaneous partial pressure of oxygen (TcPO2), the venous clinical severity scores (VCSS), the serum i TGF-ß1, TNF-α, IL-2R, and IL-1ß levels, the soluble intercellular adhesion molecule-1 (sICAM-1) levels, the soluble vascular cell adhesion molecule-1 (sVCAM-1) levels, and the quality of life scores (CIVIQ) were compared. RESULTS: The total effective rate in the experimental group was 93.33% (28/30), which was higher than the rate of 73.33% (22/30) in the control group (P < 0.05). The experimental group exhibited shorter ankle circumferences and calf circumferences, smaller subcutaneous thicknesses, lower VCSS scores, lower sICAM-1, sVCAM-1, TGF-ß1, TNF-α, IL-1ß, IL-2R, and COL1A1 levels, and higher ABI and TcPO2 levels, and higher CIVIQ scores than the control group at 6 months after the treatment (P < 0.05). CONCLUSION: Percutaneous drainage with tiny incisions has a high efficacy for CVI with LDS, and it can relieve the condition, inhibit the expression of adhesion molecules as well as the inflammatory response, improve the microcirculation of the lower extremities, reduce COL1A1 expression, and improve the quality of life.

MiR-410-3p activates the NF-κB pathway by targeting ZCCHC10 to promote migration, invasion and EMT of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is a prevalent malignancy of the digestive tract. miR-410-3p is involved in oncogenesis and development of CRC, but the specific regulation mechanism is still not known clearly. METHODS: The expression of miR-410-3p and zinc finger CCHC-type containing 10 (ZCCHC10) in CRC cells was detected by qRT-PCR and western blot method, respectively. The dual-luciferase reporter gene detection was applied for determination of interaction between miR-410-3p and ZCCHC10. The wound healing assay and transwell assay were carried out to measure cell migration and invasive ability, respectively. RESULTS: The miR-410-3p expression levels were markedly increased, but ZCCHC10 levels were reduced in CRC cells and tissues. Dual-luciferase reporter gene detection indicated that miR-410-3p targeted ZCCHC10 directly. Functionally knockdown of ZCCHC10 or overexpression of miR-410-3p activated nuclear factor-κB (NF-κB) signaling pathway, promoted epithelial-mesenchymal transition (EMT) process, as well as cell migration and invasion of CRC cells. After adding NF-κB inhibitor BAY 11-708 to inhibit NF-κB pathway, the promoting effects of si-ZCCHC10 on cell migration, invasion and EMT of HT29 and SW480 cells were suppressed. Meanwhile, overexpression of ZCCHC10 inhibited the effects of miR-410-3p on cell migration, invasion and EMT of HT29 and SW480. CONCLUSION: miR-410-3p-mediated ZCCHC10 suppression regulates NF-κB activation, thereby promoting EMT process, cell migration and invasion of CRC cells. This study provides a new insight into the specific mechanism by which miR-410-3p mediates CRC progression.

Reactivity of ynamides in catalytic intermolecular annulations.

Ynamides are unique alkynes with a carbon-carbon triple bond directly attached to the nitrogen atom bearing an electron-withdrawing group. The alkyne is strongly polarized by the electron-donating nitrogen atom, but its high reactivity can be finely tempered by the electron-withdrawing group. Accordingly, ynamides are endowed with both nucleophilic and electrophilic properties and their chemistry has been an active research field. The catalytic intermolecular annulations of ynamides, featuring divergent assembly of structurally important amino-heterocycles in a regioselective manner, have gained much attention over the past decade. This review aims to provide a comprehensive summary of the advances achieved in this area involving transition metal and acid catalysis. Moreover, the intermolecular annulations of ynamide analogs including ynol ethers and thioalkynes are also discussed, which can provide insights into the reactivity difference caused by the heteroatoms.

Visible Light Induced Bifunctional Rhodium Catalysis for Decarbonylative Coupling of Imides with Alkynes.

Transition metal catalyzed decarbonylation offers a distinct synthetic strategy for new chemical bond formation. However, the π-backbonding between CO π* orbitals and metal center d-orbitals impedes ligand dissociation to regenerate the catalyst under mild reaction conditions. Developed here is visible light induced rhodium catalysis for decarbonylative coupling of imides with alkynes under ambient conditions. Initial mechanistic studies suggest that the rhodium complex simultaneously serves as the catalytic center and photosensitizer for decarbonylation. This visible light promoted catalytic decarbonylation strategy offers new opportunities for reviewing old transformations with ligand dissociation as a rate-determining step.

Copper-catalyzed boroacylation of allenes to access tetrasubstituted vinylboronates.

A distinct copper-catalyzed boroacylation of allenes with acyl chlorides and bis(pinacolato)diboron is developed. For aromatic acyl chlorides, 1,2-boroacylation of allenes readily takes place, leading to the formation of tetrasubstituted vinylboronates with exclusive (E)-stereoselectivity. In comparison, the employment of alkyl acyl chlorides as electrophiles alters the selectivity to 2,3-boroacylated products. Additionally, the product can easily undergo Suzuki-Miyaura cross-coupling to afford tetrasubstituted alkene with complete retention of the configuration.

Cobalt-Catalyzed Regioselective Carboamidation of Alkynes with Imides Enabled by Cleavage of C-N and C-C Bonds.

Through the oxidative addition of cobalt into the N-C(O) bond of phthalimide and the subsequent decarbonylation, we describe an efficient cobalt-catalyzed intermolecular decarbonylative carboamidation of alkynes. High regioselectivities have been achieved for unsymmetrical alkynes (including aryl-alkyl or aryl-aryl) to deliver polysubstituted isoquinolones. To facilitate step economy, a three-component decarbonylative carboamidation of alkynes with phthalic anhydrides and amines has been demonstrated using the current cobalt catalysis.

Ruthenium(ii)-catalyzed intermolecular annulation of alkenyl sulfonamides with alkynes: access to bicyclic sultams.

A ruthenium-catalyzed allylic C(sp3)-H activation strategy has been employed to develop an intermolecular coupling of alkenyl sulfonamides with alkynes. This protocol features the diastereoselective construction of [3.3.0] and [4.3.0] bicyclic sultams in one step.

TET1 suppresses colon cancer proliferation by impairing ß-catenin signal pathway.

The function of ten-eleven translocation methylcytosine dioxygenase 1 (TET1) in cancer is background dependent and may be involved in the initial step of active DNA demethylation, while there is little research to decipher the role of TET1 in DNA methylation-sensitive colon cancer. Downregulated TET1 expression assayed by quantitative real-time PCR (qRT-PCR) was observed in both colon cancer samples and cancer cell lines of HT29, HCT116, and SW48. Such downregulation could promote colon cancer cells proliferation as indicated by the fact that shTET1 could increase the viability of HT29 and HCT116 cells determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide and cell count assay accompanied with upregulation of ß-catenin (CTNNB1) and WNT luciferase activity, which was further confirmed as shTET1 could increase the tumor volume and tumor weight, and decrease the body weight in HT29 cells inoculated BALB/C nude mice. The CTNNB1 transfection could rescue the cell growth diminished by normal expression of TET1. shTET1 could promote axis inhibition protein1 (AXIN1) expression and the cell proliferation effect induced by TET1 short hairpin RNA was attenuated by co-inhibition of AXIN1. All of these indicate that TET1 can suppress colon cancer proliferation and the inhibition of the ß-catenin pathway is AXIN1 dependent.

Chiral benzene backbone-based sulfoxide-olefin ligands for highly enantioselective Rh-catalyzed addition of arylboronic acids to N-tosylarylimines.

An efficient Rh-catalyzed addition of arylboronic acids to N-tosylarylimines has been developed with chiral benzene backbone-based sulfoxide-olefin ligands, where 2-methoxy-1-naphthyl sulfinyl functionalized olefin ligands have shown to be more effective. The versatile method tolerates a wide range of functional groups and shows broad scope without regard to electronic or steric substitution pattern, allowing access to a broad range of chiral diarylmethylamines in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee).

HOXB9 inhibits proliferation in gastric carcinoma cells via suppression of phosphorylated-Akt and NF-κB-dependent Snail expression.

BACKGROUND: HOXB9 is a homeobox transcription factor which plays an important role in carcinoma development. This protein has been shown to inhibit cancer cell proliferation. However, the mechanisms that underpin HOXB9-mediated inhibition of cellular proliferation remain to be elucidated. METHODS: In this study, two gastric cancer cell lines, SGC7901 and MKN45, were transfected with plasmids pLVX-HOXB9 and shHOXB9. These transfections resulted in the over-expression of the HOXB9 gene in the SGC7901/HOXB9 cells and knockdown of the HOXB9 gene in the MKN45/shHOXB9 cells. RESULTS: Over-expression of the HOXB9 gene in the SGC7901/HOXB9 cells caused an increase in the apoptotic rate and a concomitant reduction in metastatic ability compared with the knocked-down MKN45/shHOXB9 cells. Moreover, a reduction in the expression of the phosphorylated-Akt protein was observed in the SGC7901/HOXB9 cells, while an increase in expression of the same protein was observed in the MKN45/shHOXB9 cells. We also observed that HOXB9 mediated a reduction in both NF-κB and N-cadherin and Snail protein expression. Conversely, HOXB9 caused an increase in the expression of E-cadherin. CONCLUSIONS: In summary, this study reports that HOXB9 can suppress both phosphorylated-Akt expression and NF-κB activity. The latter phenomenon affects Snail protein expression and the inhibition of gastric carcinoma proliferation.

Astragalus saponins inhibit cell growth, aerobic glycolysis and attenuate the inflammatory response in a DSS-induced colitis model.

Recent studies have reported that Astragalus saponins (AST), extracted from the medicinal plant Astragalus membranaceus, possess anti­tumor and apoptosis­inducing abilities on various types of human cancer in vitro and in vivo. However, limited studies have explored how AST impacts glucose metabolism and growth conditions in vitro. The present study aimed to explore cell growth, proliferation, apoptosis and a series of glycolysis metabolic alterations associated with AST treatment in colorectal cancer (CRC) cells. MTT, a colony formation assay and flow cytometry demonstrated that AST dose­dependently inhibited cell viability and induced apoptosis. Glucose uptake and lactate production measurements revealed that AST could inhibit glycolysis metabolism and lactate production. Reverse transcription­quantitative polymerase chain reaction and western blot analysis identified that the expression levels of glycolytic enzymes were decreased by AST treatment in CRC cells. To uncover the possible impact of AST on inflammation and glucose metabolism in vivo, a dextran sulfate sodium (DSS)­induced colitis mouse model was established. Notably, AST could inhibit growth and glycolysis metabolism in CRC cells in vitro, and attenuate the inflammatory response and tumor­like aerobic glycolysis in the DSS­induced mouse model. The findings indicated that AST may have the capacity to resist tumor­associated inflammation and maintain normal glucose homeostasis, suggesting that AST could be a novel therapeutic strategy in CRC treatment.

Treatment of colon cancer in a patient with systemic lupus erythematosus: a case report.

BACKGROUND: Gastrointestinal symptoms occur in approximately 50% of patients with systemic lupus erythematous with low specificity. Although it is well established that colon cancer is one of the many gastrointestinal manifestations associated with systemic lupus erythematous, the diagnosis and treatment remains complex due to adrenal insufficiency symptoms. CASE PRESENTATION: A 43-year-old Chinese woman with a five-year history of systemic lupus erythematous was diagnosed with colon cancer based on imaging test. A radical bowel resection was performed successfully. To avoid serious complications during surgery, prednisone was replaced with methylprednisolone therefore avoiding adrenal insufficiency. The patient was subsequently treated with mFOLFOX6 chemotherapy and recovered well. CONCLUSION: There is a lack of reports for treatment of colon cancer in patients with systemic lupus erythematous. This report provides an effective way to diagnose colon cancer in patients with systemic lupus erythematous and illustrates a successful therapy strategy for this complex medical condition.

Enantiodivergent Desymmetrization in the Rhodium(III)-Catalyzed Annulation of Sulfoximines with Diazo Compounds.

RhIII - and IrIII -catalyzed asymmetric C-H functionalization reactions of arenes have relied on the employment of chiral RhIII /IrIII cyclopentadienyl catalysts, the introduction of chiral carboxylic acids to achiral Cp*RhX2 catalysts, and the integration of both strategies. Despite considerable progress, each reaction only provided a specific configuration of the enantioenriched product when using a particular chiral catalyst. Reported in this work is the enantiodivergent coupling of sulfoximines with various diazo compounds by RhIII -catalyzed desymmetrizing annulation. The enantiodivergence was enabled by a judicious choice of achiral carboxylic acids, and the enantioselectivity correlates with the steric bias of the carboxylic acid and the sulfoximine.

Loss of profilin 2 contributes to enhanced epithelial-mesenchymal transition and metastasis of colorectal cancer.

Profilin 2 (PFN2) functions as an actin cytoskeleton regulator and serves an important role in cell motility. However, a role for PFN2 in the progression of colorectal cancer (CRC), particularly in metastasis, has yet to be clarified. The aim of the present study was to investigate whether PFN2 served specific roles in the progression of human CRC. The results demonstrated that PFN2 was differentially expressed in CRC tissues and cell lines by reverse transcription-quantitative polymerase chain reaction and western blotting. PFN2 expression was also negatively associated with the degree of tumor metastasis. Low PFN2 expression in CRC cells was related with enhanced epithelial-mesenchymal transition (EMT) and, in turn, may increase migratory capabilities. Overexpression of PFN2 in CRC cell lines with a low level of endogenous PFN2 inhibited the EMT process, as well as the associated migration; in addition, myosin light chain (MLC) phosphorylation was upregulated. Inhibition of MLC phosphorylation attenuated the inhibition of EMT and cell migratory abilities induced by PFN2 overexpression in CRC cell lines, the results suggested that PFN2 may suppress cancer EMT and the subsequent metastasis by regulating cytoskeletal reorganization. These results demonstrated that PFN2 may serve a suppressive role in the metastasis of CRC and therefore may provide a new potential target for cancer therapeutics.