Copper-free Sonogashira cross-coupling reactions: an overview

The Sonogashira reaction is a cross-coupling reaction of a vinyl or aryl halide with a terminal alkyne to form a C–C bond. In its original form, the Sonogashira reaction is performed with a palladium species as a catalyst while co-catalyzed by a copper species and a phosphine or amine. The reaction is conducted under mild conditions, i.e., room temperature, aqueous solutions, and the presence of mild bases. Undeniably, the Sonogashira reaction is among the most competent and efficient reactions widely used in organic synthesis. This named reaction has proved useful in many organic synthesis areas, including the synthesis of pharmaceuticals, heterocycles, natural products, organic compounds, complex molecules having biological activities, nanomaterials, and many more materials that we use in our daily lives. The presence of transition metals as a catalyst was indeed essential in the Sonogashira reaction. However, recently, the reaction has been successfully conducted without copper as a co-catalyst and phosphines or amines as bases. In this critical review, we have focused on developments in the Sonogashira reaction successfully performed in the absence of copper complexes, phosphines or amines, which could be of particular advantage in implementing green chemistry principles and making the reactions more achievable from an economic viewpoint.

The Sonogashira reaction is a cross-coupling reaction of a vinyl or aryl halide with a terminal alkyne to form a C–C bond.     

Comparison of Physical/Chemical Properties of Prussian Blue Thin Films Prepared by Different Pulse and DC Electrodeposition Methods

Prussian Blue (PB) thin films were prepared by DC chronoamperometry (CHA), symmetric pulse, and non-symmetric pulse electrodeposition techniques. The formation of PB was confirmed by infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX) and UV-Vis transmission measurements. X-ray diffraction (XRD) shows the stabilization of the insoluble form of PB. From scanning electron microscopy (SEM) studies, an increase in porosity is obtained for the shorter pulse widths, which tends to improve the total charge exchange and electrochemical stability of the films. While the film prepared by CHA suffered a degradation of 82% after 260 cycles, the degradation reduced to 24% and 34% for the samples prepared by the symmetric and non-symmetric pulse methods, respectively. Additionally, in the non-symmetric pulse film, the improvement in the charge exchange reached ~522% after 260 cycles. According to this study, the deposition time distribution affects the physical/chemical properties of PB films. These results then render pulse electrodeposition methods especially suitable to produce high-quality thin films for electrochemical devices, based on PB.     

An overall assessment of circumanal gland adenoma in a terrier mix breed dog

In September 2012, a 10-year-old, intact male, terrier mix breed dog was evaluated because of multiple, 0.5 to 1.2 cm in diameter, round, intradermal nodules around the anus. It had surgery to excise a firm, painful swelling in the left ventrolateral perianal region and the excision part was observed under light microscopy. The mass spreading in to sub acute was of left hind leg out from the ventro-lateral of anus, 1.2 cm×1 cm/ 0 cm×0.5 cm in size and 125 g in weight. A complete blood cell count, serum biochemistry panel, and urinalysis (cystocentesis sample) were evaluated. Significant laboratory data demonstrated microcytic anemia (hemoglobin of 6.4 mg/dL) and normal coagulation times. No remarkable abnormalities were found in the complete blood count and an ionized calcium of 1.91 mmol/L (reference range, 1.1-1.3 mmol/L) was confirmed hypercalcemia. On cytologic and histopathologic examinations, evaluation of the aspirate revealed a prominent population of round-to-polygonal nucleated cells arranged as cohesive groups with isolated individual cells. A mild degree of anisocytosis and anisokaryosis was observed. In addition, smaller reserve type cells, with darker cytoplasm and a higher nucleocytoplasmic ratio. The adenomas generally retain the lobular architecture, but some may contain focal areas of cellular pleomorphism. These changes may suggest malignant transformation and have led to discordant interpretations, the well-developed stroma surrounding the lobules and hepatoid cells was noted. Ulceration, hemorrhage, necrosis and secondary infection with inflammatory cell infiltrates are common. These cytology and histopathology features are consistent with hepatoid gland adenoma.     

Upregulation of KAT2B and ESCO2 gene expression level in patients with rheumatoid arthritis

Clinical Rheumatology - Rheumatoid arthritis (RA) is an autoimmune condition that causes progressive inflammation. It seems that alternations in epigenetic modifications contribute to RA...     

Iranian guideline for rituximab therapy in pemphigus patients

Pemphigus vulgaris (PV) is an autoimmune blistering disease affecting the skin and/or mucosa. Rituximab (RTX) has been approved recently by US FDA as an effective and safe treatment of PV. The high incidence of PV in Iran encouraged our team to prepare a consensus guideline for RTX administration based on literature review and a decade experience of an expert panel. RTX is recommended for the treatment of new cases of PV as well as patients not responding to conventional therapy. Contraindications include history of anaphylaxis or IgE‐mediated hypersensitivity to murine proteins of RTX, severe active infections, pregnancy, breastfeeding, severe heart failure, and arrhythmia. Prophylactic antiviral therapy is recommended in patients at risk of reactivation of HBV and isoniazid for those at risk of reactivation of tuberculosis. Concomitant use of systemic corticosteroids is recommended as a rule. Except for methotrexate, the combination with other immunosuppressive drugs is discouraged. Intravenous immunoglobulin is recommended for those at risk of infections or with extensive disease. The recommended dosage of RTX for the first cycle is 2 g either 500 mg weekly or 1 g biweekly. There is no general consensus whether the next doses of RTX be administered upon relapse or as maintenance therapy. We strongly recommend RTX sooner in the course of pemphigus.     

The expression of GAS5, THRIL,and RMRP lncRNAs is increased in T cells of patients with rheumatoid arthritis

Clinical Rheumatology - Long non-coding RNAs (lncRNAs) comprise a large and diverse group of non-coding RNAs (ncRNAs) with important regulatory roles in various biological processes, including the...     

The conversion in application of percutaneous coronary intervention following the introduction of drug eluting stents

In order to determine the changes in the pattern of techniques applied during elective coronary intervention, data from 688 patients prior to Sirolimus. Drug-Eluting Stents (DES) approval was compared to 438 patients who underwent coronary intervention after DES approval. There was increased intervention to higher risk lesions, including smaller vessels and re-stenotic lesions after DES approval. Total number of stents per patient significantly decreased, despite longer stent length per patient or per lesion after DES approval. No significant difference was found in multivessel interventions.     

A review of anti-inflammatory,antioxidant, and immunomodulatory effects of Allium cepa and its main constituents

ContextAllium cepa L. (Liliaceae), known as onion, is consumed throughout the world. Onion and its derivatives including saponins, aglycones, quercetin, cepaenes, flavonoids, organosulfurs, and phenolic compounds, showed various pharmacological properties and therapeutic effects.ObjectiveAnti-inflammatory, antioxidant, and immunomodulatory effects of A. cepa and its main constituents, along with the underlying molecular mechanisms are presented.MethodsDatabases including, Web of Knowledge, Medline/PubMed, Scopus, and Google Scholar were checked for articles published between 1996 and the end of July 2020, using the key-words Allium cepa, quercetin, anti-inflammatory, antioxidant and immunomodulatory.ResultsA. cepa and its constituents mainly quercetin showed anti-inflammatory effects mediated via reduction of total and differential WBC counts, inhibition of chemotaxis of polymorphonuclear leukocytes, COX, and LOX pathways and prevented formation of leukotrienes and thromboxanes, prostaglandin E2 (PGE2) as onVCAM-1, NF-κB, MARK,d STAT-1, JNK, p38 and osteoclastogenesis. A. cepa and its derivatives showed antioxidant effect by decreasing lipid peroxidation, NAD(P)H, MDA, NO, LPO and eNOS but enhancing antioxidants such as SOD, CAT, GSH, GPx, GSPO, TrxR, SDH, GST and GR activities and thiol level. Immunomodulatory effects of the plant and quercetin was also shown by reduction of Th2 cytokines, IL-4, IL-5, and IL-13 as well as IL-6, IL-8, IL-10, IL-1β and TNF-α and IgE levels, but increased CD4 cells, IFN-γ level and IFN-γ/IL4 ratio (Th1/Th2 balance).ConclusionsThe effect of onion and its constituents on oxidative stress, inflammatory and immune system were shown indicating their therapeutic value in treatment of various diseases associated with oxidative stress, inflammation, and immune-dysregulation.