Regio- and Stereoselective Installation of Bromide onto Vinyl Sulfonyl Fluorides: Construction of a Class of Versatile Sulfur Fluoride Exchange Hubs

A convenient protocol for the exclusively regio- and stereoselective installation of a bromine atom on the 2-arylvinylsulfonyl fluorides using lithium bromide (LiBr) as the bromine source was described, providing (Z)-1-bromo-2-arylethene-1-sulfonyl fluorides (Z-BASF) with versatile reactive handles (bromide, vinyl, and sulfonyl fluoride) in ≤88% yield. Meanwhile, Z-BASF molecules displayed various reactivities in a series of chemical transformations.

Clickable Transformation of Nitriles (RCN) to Oxazolyl Sulfonyl Fluoride Warheads

The protocol for simple, efficient, and mild synthesis of oxazolyl sulfonyl fluorides was developed through Rh₂(OAc)₄-catalyzed annulation of methyl-2-diazo-2-(fluorosulfonyl)acetate (MDF) or its ethyl ester derivative with nitriles. This practical method provides a general and direct route to a unique class of highly functionalized oxazolyl-decorated sulfonyl fluoride warheads with great potential in medicinal chemistry, chemical biology, and drug discovery.

A Simple Protocol for the Stereoselective Construction of Enaminyl Sulfonyl Fluorides

A clickable connective hub 1-bromo-2-triazolethane-1-sulfonyl fluoride BTESF (1) was developed and successfully applied for the fluorosulfonylvinylation of a host of primary and secondary cyclic or acyclic amines including amino acids and pharmaceuticals. Further antimicrobial experiments revealed that vinyl sulfonyl fluoride functionalized norfloxacin (3ak), ciprofloxacin (3am), and lomefloxacin (3an) exhibited 4-fold improved antimicrobial activity against Gram-positive bacteria compared to their parent drugs.

Copper-catalyzed mild desulfonylation of vinyl sulfonyl molecules

The first Cu-catalyzed chemical selective desulfonylation of vinyl sulfonyl molecules to olefins was developed using B₂pin₂–water as the reductant.

Ethenesulfonyl Fluoride (ESF) and Its Derivatives in SuFEx Click Chemistry and More

The sulfur(VI) fluoride exchange reaction (SuFEx), developed by Sharpless and co-workers in 2014, is a new category of click reaction that creates molecular connections with absolute reliability and unprecedented efficiency through a sulfur(VI) hub. Ethenesulfonyl fluoride (ESF), as one of the most important sulfur(VI) hubs, exhibits extraordinary reactivity in SuFEx click chemistry and organic synthesis. This review summarizes the chemical properties and applications of ESF in click chemistry, organic chemistry, materials science, medicinal chemistry and in many other fields related to organic synthesis.

1 Introduction

2 Chemical Transformations of ESF

3 Chemical Transformations of 2-Arylethenesulfonyl Fluorides

4 Novel SuFEx Reagents Derived from ESF

5 Applications of ESF Derivatives in Medicinal Chemistry

6 Applications of ESF Derivatives in Materials Science

7 Conclusion

Rh-Catalyzed Highly Enantioselective Synthesis of Aliphatic Sulfonyl Fluorides

Rh-catalyzed, highly enantioselective (up to 99.8% ee) synthesis of aliphatic sulfonyl fluorides was accomplished. This protocol provides a portal to a class of novel 2-aryl substituted chiral sulfonyl fluorides, which are otherwise extremely difficult to access. This asymmetric synthesis has the feature of mild conditions, excellent functional group compatibility, and wide substrate scope (51 examples) generating a wide array of structurally unique chiral β-arylated sulfonyl fluorides for sulfur(VI) fluoride exchange (SuFEx) click reaction and drug discovery.

Synthetic approaches and pharmaceutical applications of chloro-containing molecules for drug discovery: A critical review

At present more than 250 FDA approved chlorine containing drugs were available in the market and many pharmaceutically important drug candidates in pre-clinical trials. Thus, it is quite obvious to expect that in coming decades there will be an even greater number of new chlorine-containing pharmaceuticals in market. Chlorinated compounds represent the family of compounds promising for use in medicinal chemistry. This review describes the recent advances in the synthesis of chlorine containing heterocyclic compounds as diverse biological agents and drugs in the pharmaceutical industries for the inspiration of the discovery and development of more potent and effective chlorinated drugs against numerous death-causing diseases.

Cascade Process for Direct Transformation of Aldehydes (RCHO) to Nitriles (RCN) Using Inorganic Reagents NH2OH/Na2CO3/SO2F2 in DMSO

A simple, mild, and practical process for direct conversion of aldehydes to nitriles was developed feathering a wide substrate scope and great functional group tolerability (52 examples, over 90% yield in most cases) using inorganic reagents (NH₂OH/Na₂CO₃/SO₂F₂) in DMSO. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable nitriles in a pot, atom, and step-economical manner without transition metals. This protocol will serve as a robust tool for the installation of cyano-moieties to complicated molecules.

Pharmaceutical and medicinal significance of sulfur (SVI)-Containing motifs for drug discovery: A critical review

Sulfur (S^VI) based moieties, especially, the sulfonyl or sulfonamide based analogues have showed a variety of pharmacological properties, and its derivatives propose a high degree of structural diversity that has established useful for the finding of new therapeutic agents. The developments of new less toxic, low cost and highly active sulfonamides containing analogues are hot research topics in medicinal chemistry. Currently, more than 150 FDA approved Sulfur (S^VI)-based drugs are available in the market, and they are widely used to treat various types of diseases with therapeutic power. This comprehensive review highlights the recent developments of sulfonyl or sulfonamides based compounds in huge range of therapeutic applications such as antimicrobial, anti-inflammatory, antiviral, anticonvulsant, antitubercular, antidiabetic, antileishmanial, carbonic anhydrase, antimalarial, anticancer and other medicinal agents. We believe that, this review article is useful to inspire new ideas for structural design and developments of less toxic and powerful Sulfur (S^VI) based drugs against the numerous death-causing diseases.

Regioselective installation of fluorosulfate (–OSO2F) functionality into aromatic C(sp2)–H bonds for the construction of para-amino-arylfluorosulfates

The synthesis of novel para-amino-arylfluorosulfates was achieved through installing fluorosulfate functionality into aromatic C(sp²)–H bonds mediated by sulfuryl fluoride.

[Effect of paraquat on the expression of a disintegrin and metalloproteinase-17 in A549 cells]

Objective: Construct a paraquat (PQ) cell fibrosis model in vitro, observe the effect of PQ on the expression of a disintegrin and metalloproteinase-17 (ADAM17) in A549 cells, and explore the role of ADAM17 in the pulmonary fibrosis induced by PQ poisoning. Methods: A549 cells are divided into normal control group, different concentration of PQ groups, CCK-8 is used to detect cell viability, screening concentration and time of PQ, cell morphology is observed under microscope; Enzyme-linked immunosorbent assay (ELISA) detectes fibrosis markers of collagen type I (Col I) and fibronectin (FN) expression. Establishment of cell model of fibrosis; distribution by immunocytochemical detection of ADAM17 in A549 cells, Reverse transcription-polymerase chain reaction and Western blot are used to detect the expression of ADAM17 mRNA and protein. Results: 1. With the increase of PQ concentration and the prolongation of the action time, the activity of A549 cells decreased (P< 0.05) , which is dose-dependent and time dependent. 2.The normal A549 cells fusion is paving stone growth and arranged more closely. After PQ induction, the cell arrangement was loose, the intercellular connection became loose, and some cells dissolved and died. 3.ELISA showed that with the increase of PQ concentration, the expression of Col I and FN increased (P<0.05) , and Col I and FN expression gradually increased with the prolongation of PQ time (P<0.05) , and the fibroblast model is successfully established. 4. Immunocytochemistry showes that ADAM17 is expressed in the cytoplasm of A549 cells. 5. RT-PCR and Western blot showed that the expression of ADAM17 mRNA and protein increased significantly with the increase of PQ concentration (P<0.05) , which is most obvious at PQ 200 μmol/L. With the prolonged action of PQ, the expression level of ADAM17 mRNA and protein also increased significantly (P<0.05) , and reached the peak in 24 h. Conclusion: PQ can induce morphological changes of alveolar epithelial cells, cause cell damage, and successfully establish a cell fibrosis model, which has a dose and time dependence on the toxicity of A549 cells. ADAM17 is overexpressed in the A549 cells induced by PQ and may be involved in the process of pulmonary fibrosis induced by paraquat.

Pd-Catalyzed one-pot dehydroxylative coupling of phenols with K4[Fe(CN)6] mediated by SO2F2: a practical method for the direct conversion of phenols to aryl nitriles

A SO₂F₂ mediated Pd-catalyzed one-pot dehydroxylative cyanation of phenols to aryl nitriles was accomplished by employing (K₄[Fe(CN)₆]) as the cyanating reagent.

A portal to a class of novel sultone-functionalized pyridines via an annulative SuFEx process employing earth abundant nickel catalysts

An efficient Ni²⁺ promoted process for the synthesis of a class of structurally unique heterocycles containing both pyridines and sultones was developed through a SuFEx annulation. This protocol serves as an irreplaceable asset for medicinal chemistry and drug discovery.

Amino acids/peptides conjugated heterocycles: A tool for the recent development of novel therapeutic agents

Amino acids/peptide conjugated heterocycles represent an important class of therapeutical agents. Biologically active heterocycles are conjugated with amino acids or peptides to increase the drug resistance. Furthermore, the amino acid/peptide based drugs have low toxicity, ample bioavailability and permeability, modest potency and good metabolic and pharmacokinetic properties. Synthetic amino acid/peptides based heterocyclic conjugates constitute a promising choice for the development of new, less toxic and safer conventional pharmaceutical drugs in the near future. In this review, we discuss and highlight the recent findings of the structural features that encourage biological applications of amino acid/peptides based conjugates.

SO2 F2 -Mediated One-Pot Synthesis of Aryl Carboxylic Acids and Esters from Phenols through a Pd-Catalyzed Insertion of Carbon Monoxide

A one-pot Pd-catalyzed carbonylation of phenols into their corresponding aryl carboxylic acids and esters through the insertion of carbon monoxide has been developed. This procedure offers a direct synthesis of aryl carboxylic acids and esters from inexpensive and abundant starting materials (phenols, SO₂ F₂ and CO) under mild conditions. This method tolerates a broad range of functional groups and is also applicable for the modification of complicated natural products.

Natural Proline-Rich Cyclopolypeptides from Marine Organisms: Chemistry, Synthetic Methodologies and Biological Status

Peptides have gained increased interest as therapeutics during recent years. More than 60 peptide drugs have reached the market for the benefit of patients and several hundreds of novel therapeutic peptides are in preclinical and clinical development. The key contributor to this success is the potent and specific, yet safe, mode of action of peptides. Among the wide range of biologically-active peptides, naturally-occurring marine-derived cyclopolypeptides exhibit a broad range of unusual and potent pharmacological activities. Because of their size and complexity, proline-rich cyclic peptides (PRCPs) occupy a crucial chemical space in drug discovery that may provide useful scaffolds for modulating more challenging biological targets, such as protein-protein interactions and allosteric binding sites. Diverse pharmacological activities of natural cyclic peptides from marine sponges, tunicates and cyanobacteria have encouraged efforts to develop cyclic peptides with well-known synthetic methods, including solid-phase and solution-phase techniques of peptide synthesis. The present review highlights the natural resources, unique structural features and the most relevant biological properties of proline-rich peptides of marine-origin, focusing on the potential therapeutic role that the PRCPs may play as a promising source of new peptide-based novel drugs.

Silver-mediated direct trifluoromethoxylation of α-diazo esters via the (-)OCF3 anion

Silver-mediated direct trifluoromethoxylation of α-diazo esters and ketosteroid was disclosed. The reactions of alkyl α-diazo arylacetates with AgOCF3 or CF3SO2OCF3/AgF at -30 to 10 °C under a N2 atmosphere provided α-trifluoromethoxyl arylacetates in up to 90% yield, while alkyl α-diazo vinylacetates reacting with CF3SO2OCF3/AgF or AgOCF3 afforded γ-trifluoromethoxyl α,β-unsaturated esters in up to 94% yield. The α-diazo ketosteroid was also trifluoromethoxylated under the standard reaction conditions. This protocol allows for an effective and convenient access to a large number of synthetic building blocks, which are promising in the development of new functional OCF3-molecules.

Expeditious trifluoromethylthiolation and trifluoromethylselenolation of alkynyl(phenyl)iodoniums by [XCF3]− (X = S, Se) anions

Metal- and additive-free trifluoromethylthiolation and trifluoromethylselenolation of alkynyl(phenyl)iodoniums by [XCF₃]⁻ (X = S, Se) anions was accomplished in 5–10 minutes.

BRAF mutation correlates with recurrent papillary thyroid carcinoma in Chinese patients

PURPOSE

We investigated correlations of somatic BRAF V600E mutation and RET/PTC1 rearrangement with recurrent disease in Chinese patients with papillary thyroid carcinoma (ptc).

METHODS

This prospective study included 214 patients with ptc histologically confirmed between November 2009 and May 2011 at a single institute.

RESULTS

We found somatic BRAF V600E mutation in 68.7% and RET/PTC1 rearrangement in 25.7% of the patients. Although BRAF mutation was not significantly associated with clinicopathologic features such as patient sex or age, multicentric disease, thyroid capsule invasion, tumour stage, or nodal metastasis, it was significantly associated with recurrent disease. Multivariate analysis revealed that BRAF mutation and tumour size were independent risk factors associated with recurrent disease, with odds ratios of 9.072 and 2.387 respectively. The area under the receiver operating characteristic curve increased 8.3% when BRAF mutation was added to the traditional prognostic factors, but that effect was statistically nonsignificant (0.663 vs. 0.746, p = 0.124). RET/PTC1 rearrangement and nodal metastasis were significantly associated in all patients (p = 0.042), marginally associated in ptc patients (p = 0.051), but not associated in microptc patients (p = 0.700). RET/PTC1 rearrangement was not significantly associated with recurrent disease.

CONCLUSIONS

BRAF positivity is an independent predictor of recurrent disease in ptc.

Percutaneous balloon mitral valvuloplasty. An observation of 50 patients

Percutaneous balloon mitral valvuloplasty (PBMV) was successfully performed in 50 selected patients with mitral stenosis by using Inoue pillow-shaped balloon and Inoue technique. The average diameter of balloon used was 26.9 +/- 0.9 mm. 90% (45/50) of cases had either double or single mitral commissura split. Of the rest 5 cases, 1 had a mitral score 13 and 4 had a history of mitral valve commissurotomy. Totally they had a mean mitral valve area increase from 1.13 +/- 0.32 to 2.21 +/- 0.43 cm2, left atrial pressure decrease from 31.8 +/- 9.3 to 14.7 +/- 5.6 mmHg, left atrial diameter reduction from 44.9 +/- 7.7 to 37.4 +/- 4.9 mm, and transmitral gradient decrease from 21.7 +/- 9.8 to 4.0 +/- 5.2 mmHg. Most patients had a obvious cardiac function improvement, especially in patients with mitral score of 8 or less. 30% patients (15/50) had a mild mitral regurgitation, but relieved 3-6 months after procedure. During one year of follow up, the majority of patients (16/20) were found in a good cardiac function, mitral area and the left atrial diameter, except in 4 patients with a high mitral score of more than 10. It is suggested that for patient with lower mitral morphological score and good general health, a larger diameter balloon might be suitable for effectively improving patient's symptom, but for patients with a previous surgical mitral commissurotomy, PBMV should not be selected.

Antithrombotic effects of Andrographis paniculata nees in preventing myocardial infarction

In 16 dogs the endothelium of the left anterior descending coronary artery was injured mechanically. Then a copper wire was inserted into the lumen as a choke of flow and the vessel was slightly compressed from outside by a constrictor. Eight dogs had been treated beforehand with a preparation of flavone extracted from the root of the Chinese medicinal herb Andrographis paniculata (TFAP). In the control group, saline solution was given, the epicardially recorded ST segment started to elevate within 15 minutes, the platelet aggregation rate and the plasma levels of TXB2 increased rapidly, whereas the level of 6-k-PGF1 alpha remained stable. Platelet cGMP rose continuously; however, platelet cAMP rose only at 60 minutes. Histological findings confirmed the occurrence of arterial thrombus and myocardial necrosis. Contrariwise, in the pretreated group there was no elevation of the ST segment, plasma 6-k-PGF1 alpha and platelet cAMP were increased, the production of TXB2 and aggregation of platelets were inhibited, and no thrombus or myocardial infarction was induced. All data suggest that TFAP might promote the synthesis of PGI2, inhibit the production of TXA2, stimulate the synthesis of cAMP in platelets, impede aggregation of platelets, and thereby prevent the formation of thrombi as well as the development of myocardial infarction.

Protective effects of andrographis paniculata nees on post-infarction myocardium in experimental dogs

One hour after the development of myocardial infarction by formation of thrombus, watery extract of Andrographis paniculata Nees (APN) was injected intravenously to 7 dogs for observing the protective effect of this drug on ischemic myocardium, 6 dogs served as control group. In the treated group PGI2 increased remarkably, synthesis of TXA2 was inhibited, cAMP in platelets was elevated, CK-MB peak was lowered and appeared earlier, ELT was shortened, release of platelet beta-GT was decreased, platelet maximum aggregation rate was inhibited, the size of ischemic area recorded by epicardial ECG was reduced, the amplitude of ST segment elevation was lower than that in the control group, Q wave appeared in only one dog. Pathologically, the myocardial structure surrounding the initially appearing ischemic area, i.e, the reversibly damaged area, became relatively normal, while the degree of myocardial degeneration and necrosis in the central part of the ischemic area was mild. These data suggest that APN may limit the expansion of ischemic focus, exert marked protective effect on reversibly ischemic myocardium and demonstrate a weak fibrinolytic action.

The effects of dauricine and verapamil as calcium channel blockers on the plasma concentration of 6-keto-prostaglandin F1 alpha and thromboxane B2 during cardiopulmonary bypass

Three groups of ten dogs underwent 80 minutes cardiopulmonary bypass. Two of the three groups were administered dauricine, as a new calcium channel blocker, and verapamil, as a generally recognized calcium channel blocker, respectively, from 15 minutes pre-bypass to the end of the bypass procedure (a period of 95 minutes). By means of radioimmunoassay plasma 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TxB2) as the stable metabolites of prostacyclin and thromboxane A2 were surveyed. During the aortic clamping the hemodynamic changes were recorded. The dauricine and verapamil groups showed markedly inhibited generation of excessive 6-keto-PGF1 and TxB2, a narrowed ratio of TxB2 to 6-keto-PGF1 alpha, as well as a reduced total systemic peripheral resistance within the perfusion period. These results suggest that dauricine and verapamil have a salutary effect in extracorporeal circulation. The possible mechanisms are discussed.