Relay Annulation of Ammonium Ylides with Oxindole-Derived α,ß-Unsaturated Ketimines: Catalytic Construction of Spiro-polycyclic Oxindoles.

An ammonium ylide-based relay annulation was disclosed, which uses DABCO as the catalyst and oxindole-derived α,ß-unsaturated ketimines and γ-bromo-crotonates as the starting materials. This method enables the rapid assembly of a series of structurally novel spiro-polycyclic oxindoles containing a bicyclo[4.1.0]heptane moiety through simultaneous generation of three new bonds and two rings in one step under mild reaction conditions.

1,5-Hydrogen atom transfer of α-iminyl radical cations: a new platform for relay annulation for pyridine derivatives and axially chiral heterobiaryls.

The exploitation of new reactive species and novel transformation modes for their synthetic applications have significantly promoted the development of synthetic organic methodology, drug discovery, and advanced functional materials. α-Iminyl radical cations, a class of distonic ions, exhibit great synthetic potential for the synthesis of valuable molecules. For their generation, radical conjugate addition to α,ß-unsaturated iminium ions represents a concise yet highly challenging route, because the in situ generated species are short-lived and highly reactive and they have a high tendency to cause radical elimination (ß-scission) to regenerate the more stable iminium ions. Herein, we report a new transformation mode of the α-iminyl radical cation, that is to say, 1,5-hydrogen atom transfer (1,5-HAT). Such a strategy can generate a species bearing multiple reactive sites, which serves as a platform to realize (asymmetric) relay annulations. The present iron/secondary amine synergistic catalysis causes a modular assembly of a broad spectrum of new structurally fused pyridines including axially chiral heterobiaryls, and exhibits good functional group tolerance. A series of mechanistic experiments support the α-iminyl radical cation-induced 1,5-HAT, and the formation of several radical species in the relay annulations. Various synthetic transformations of the reaction products demonstrate the usefulness of this relay annulation protocol for the synthesis of significant molecules.

Modular Assembly of 2-Aminoaniline Derivatives by Merging Hydroxylamine-Passerini and Hetero-Cope Rearrangement.

A metal-free three-component protocol that combines a hydroxylamine-Passerini reaction and hetero-Cope rearrangement was realized, which enables the modular assembly of a wide range of structurally new and interesting 2-aminoanilines bearing an α-hydroxyamide substructure.

Skeletal Transformation of Oxindoles into Quinolinones Enabled by Synergistic Copper/Iminium Catalysis.

We describe a synergistic Cu/secondary amine catalysis for skeletal transformation of an oxindole core into a quinolinone skeleton, which generates several structurally new pyridine-fused quinolinones. The synergistic reactions allow expansion of a five-membered lactam ring by radical cation-triggered C-C bond cleavage and enable a further intramolecular cyclization with the aim to construct totally distinct core skeletons.

Iminyl radical-triggered relay annulation for the construction of bridged aza-tetracycles bearing four contiguous stereogenic centers.

Bridged tetracyclic nitrogen scaffolds are found in numerous biologically active molecules and medicinally relevant structures. Traditional methods usually require tedious reaction steps, and/or the use of structurally specific starting materials. We report an unprecedented, iminyl radical-triggered relay annulation from oxime-derived peresters and azadienes, which shows good substrate scope and functional group compatibility, and can deliver various bridged aza-tetracyclic compounds with complex molecular topology and four contiguous stereogenic centers (dr > 19 : 1) in a single operation. This transformation represents the first example of trifunctionalization of iminyl radicals through simultaneous formation of one C-N and two C-C bonds. DFT calculation studies were conducted to obtain an in-depth insight into the reaction pathways, which revealed that the reactions involved an interesting 1,6-hydrogen atom transfer process.

Deconstructive Insertion of Oximes into Coumarins: Modular Synthesis of Dihydrobenzofuran-Fused Pyridones.

In the presence of a copper catalyst, a series of oximes undergo deconstructive insertion into coumarins to afford structurally interesting dihydrobenzofuran-fused pyridones in moderate to good yields with good functional group compatibility. The reaction likely involves a radical relay annulation, leading to the ring opening of the lactone moiety of the coumarins, and simultaneous formation of three new bonds. The investigation of photoluminescent properties reveals that several obtained compounds may have potential as fluorescent materials.

Two new lignans from Zanthoxylum armatum.

Zanthoxylum armatum, its peels possessed better special flavour, as well as various bioactivities, such as anti-inflammatory, anti-microbial and anti-tumour. In our chemical investigation on the peels of Z. armatum, two new lignans (1 and 2) and three known lignans (3-5) were isolated by silica gel column chromatography, ODS column and preparative HPLC and their structures were established as zanthlignans A and B (1-2), (-)-asarinin (3), phylligenin (4) and planispine A (5) through various spectroscopic techniques including UV, IR, HR-ESI-MS, NMR and CD methods.

[Network pharmacological analysis and experimental verification of anti-inflammatory and analgesic effect of Zanthoxyli Pericarpium].

To explore the mechanism of anti-inflammatory and analgesic effect of Zanthoxyli Pericarpium based on network pharmacology and inflammatory or pain mouse models. The effective components of Zanthoxyli Pericarpium were screened out by TCMSP database. And their potential corresponding targets were predicted by PharmMapper software. The possible targets relating to inflammation and pain were mainly collected through DrugBank, TTD and DisGeNET databases. The "active ingredient-gene-disease" network diagram was constructed by Cytoscape 3.7.0 software. The network pharmacology results showed 5 potential effective compounds, which were related to 29 targets; 132 targets relating to inflammation and pain were screened out in the DrugBank, TTD and DisGeNET databases. The network analysis results indicated that the phosphatidylinositol 3-kinase catalytic subunit gamma isoform(PIK3 CG) gene may be the key to the anti-inflammatory and analgesic effect of Zanthoxyli Pericarpium. The anti-inflammatory and analgesic effects of essential oil extract and dichloromethane extract of Zanthoxyli Pericarpium were explored through the mouse model of inflammation induced by xylene or carrageenan and the mouse model of pain induced by acetic acid or formalin. The experimental results showed that essential oil extract and dichloromethane extract of Zanthoxyli Pericarpium could reduce xylene-induced ear swelling and carrageenan-induced paw swelling and decrease the number of writhing responses in mice induced by acetic acid and the licking foot time of mice in phase Ⅱ induced by formalin. Western blot results showed that Zanthoxyli Pericarpium extract could inhibit the expressions of PIK3 CG, phosphonated nuclear factor kappaB(p-NF-κB) and phosphonated p38(p-p38 MAPK) protein. The present study showed the anti-inflammatory and analgesic effect of Zanthoxyli Pericarpium through multiple components and targets, so as to provide a pharmacodynamic basis for the study of Zanthoxyli Pericarpium and its mechanism.

OnclncRNA-626 promotes malignancy of gastric cancer via inactivated the p53 pathway through interacting with SRSF1.

Gastric cancer (GC) is a serious health problem worldwide. The potential involvement of long noncoding RNAs in GC progression remains largely unexplored. Here, we identified a novel long noncoding RNA referred to as onclncRNA-626 (oncogenic lncRNA RP11-626H12.3), which was highly upregulated in GC tissues. The high expression levels of onclncRNA-626 in GC patients predicted poor prognoses. Functional assays indicated that onclncRNA-626 could promote the proliferation and metastasis of GC cells in vitro and in vivo. In exploring the molecular mechanisms guiding these functions, we found that onclncRNA-626 specifically interacted with serine- and arginine-rich splicing factor 1 (SRSF1) and increased its stability. SRSF1 was upregulated in GC tissues and correlated with onclncRNA-626 expression and patient survival. Furthermore, RNA-seq data revealed that onclncRNA-626 affected multiple signaling pathways, including the p53 signaling pathway. Rescue experiments showed that onclncRNA-626 probably performed its biological function through SRSF1 mediation of the p53 pathway. Together, our findings demonstrate that onclncRNA-626 promotes GC progression by binding SRSF1; further, this lncRNA is a potential prognostic biomarker for GC patients.

Copper(II)-Catalyzed Alkene Aminosulfonylation with Sodium Sulfinates For the Synthesis of Sulfonylated Pyrrolidones.

A copper-catalyzed direct aminosulfonylation of unactivated alkenes with sodium sulfinates for the efficient synthesis of sulfonylated pyrrolidones is described. This reaction features good functional group tolerance and wide substrate scope, providing an efficient and straightforward protocol to access this kind of pyrrolidones. Moreover, preliminary mechanistic investigations disclosed that a free-radical pathway might be invovled in the process.

Selective O-Cyclization of N-Methoxy Aryl Amides with CH2Br2 or 1,2-DCE via Palladium-Catalyzed C-H Activation.

A selective O-cyclization of N-methoxy aryl amides with CH2Br2 or 1,2-DCE (1,2-dichloroethane) via palladium-catalyzed C-H activation has been described. New C(sp3)-O and C(sp2)-C(sp3) bonds are forged simultaneously with the assistance of an N-methoxy amide group, and good functional group tolerance in substrates is observed. Preliminary mechanistic investigations show that the process may involve a five-membered palladacycle intermediate.

Asymmetric Synthesis of 1,3-Oxazolidine Derivatives with Multi-Component Reaction and Research of Kinetic Resolution.

An efficient multi-component reaction to synthesize multi-substituted 1,3-oxazolidine compounds of high optical purity was described. All the products were well-characterized and the absolute configuration of one chiral center was determined. The plausible mechanism was proposed and a kinetic resolution of epoxides process was confirmed.

Stable acyclic aliphatic solid enols: synthesis, characterization, X-ray structure analysis and calculations.

A synthetic approach to stable enols was introduced and series of acyclic aliphatic solid enols were obtained and characterized. Relationship between the structure and the stability of these enols was discussed. Gaussian 09 calculations had been carried out to rationalize the stability of the enols. These enol structures were confirmed by (1)H NMR, (13)C NMR, MS, IR, partly by single crystal X-ray structure analysis and the protons exchange experiments. This work showed that very stable acyclic aliphatic enols can be synthesized efficiently without any purification.

[4 + 3] Cycloaddition of aromatic α,ß-unsaturated aldehydes and ketones with epoxides: one-step approach to synthesize seven-membered oxacycles catalyzed by Lewis acid.

A novel intermolecular [4 + 3] cycloaddition method to construct 1,4-dioxide seven-membered oxacycles was developed. This one-step method was carried out in the presence of catalytic amount of (C(2)H(5))(2)OBF(3) under mild conditions. Seven-membered oxacycles and some natural compounds could be easily synthesized via this protocol. Control experiments were carried out and possible mechanism for the reaction was proposed. Asymmetric reactions were proceeded and 3e was obtained with moderate ee value.