A highly para-selective amination of anilines with phenothiazines for producing various functionalized 10-aryl-10H-phenothiazines is reported. The oxidative amination reaction proceeds ...electrochemically at room temperature, thereby avoiding the use of metals and oxidizing reagents with excellent functional group tolerance and broad substrate scope.
Here we describe the one‐pot construction of the pyrrolo4,3,2‐dequinolinone scaffold by a cascade nitration/cyclization sequence of 1,7‐enynes with tBuONO and H2O. The cascade proceeds through alkene ...nitration, 1,7‐enyne 6‐exo‐trig cyclization, CH nitrations, and redox cyclization, and exhibits excellent functional group tolerance. The mechanism was investigated using in situ high‐resolution mass spectrometry (HR‐MS).
Nitration cascade: The pyrrolo4,3,2‐dequinolinone scaffold was synthesized by a metal‐free reaction of N‐(2‐(ethynyl)aryl)acrylamides, tert‐butyl nitrite and H2O. This cascade reaction is triggered by alkene nitration followed by 1,7‐enyne 6‐exo‐trig cyclization, CH nitrations, and redox cyclization and forms the product in good yields.
Existing clinical studies supported the potential efficacy of mesenchymal stromal cells as well as derived exosomes in the treatment of COVID-19. We aimed to explore the safety and efficiency of ...aerosol inhalation of the exosomes derived from human adipose-derived MSCs (haMSC-Exos) in patients with COVID-19.
The MEXCOVID trial is a phase 2a single-arm, open-labelled, interventional trial and patients were enrolled in Jinyintan Hospital, Wuhan, China. Eligible 7 patients were assigned to receive the daily dose of haMSCs-Exos (2.0 × 10
nano vesicles) for consecutively 5 days. The primary outcomes included the incidence of prespecified inhalation-associated events and serious adverse events. We also observed the demographic data, clinical characteristics, laboratory results including lymphocyte count, levels of D-dimer and IL-6 as well as chest imaging.
Seven severe COVID-19 related pneumonia patients (4 males and 3 females) were enrolled and received nebulized haMSC-Exos. The median age was 57 year (interquartile range (IQR), 43 year to 70 year). The median time from onset of symptoms to hospital admission and administration of nebulized haMSC-Exos was 30 days (IQR, 15 days to 40 days) and 54 d (IQR, 34 d to 69 d), respectively. All COVID-19 patients tolerated the haMSC-Exos nebulization well, with no evidence of prespecified adverse events or clinical instability during the nebulization or during the immediate post-nebulization period. All patients presented a slight increase of serum lymphocyte counts (median as 1.61 × 10
/L vs. 1.78 × 10
/L). Different degrees of resolution of pulmonary lesions after aerosol inhalation of haMSC-Exos were observed among all patients, more obviously in 4 of 7 patients.
Our trial shows that a consecutive 5 days inhalation dose of clinical grade haMSC-Exos up to a total amount of 2.0 × 10
nano vesicles was feasible and well tolerated in seven COVID-19 patients, with no evidence of prespecified adverse events, immediate clinical instability, or dose-relevant toxicity at any of the doses tested. This safety profile is seemingly followed by CT imaging improvement within 7 days. Further trials will have to confirm the long-term safety or efficacy in larger population.
MEXCOVID, NCT04276987.
A novel tandem annulation of N-(o-ethynylaryl)acrylamides, with CH2Cl2 as a one-carbon unit, for the divergent synthesis of cyclopentacquinolin-4(5H)-ones and ...benzojphenanthridin-6(5H)-ones, which relies on the substitution effect of the 2 position of the acrylamide moiety, is described. Promoted by the visible-light photoredox catalysis, this reaction allows the formation of multiple chemical bonds through multiple C–Cl/C–H functionalization and 2 + 2 + 1 annulation cascades.
Difunctionalization: Inexpensive and environmentally benign FeCl3 catalyzes the oxidative 1,2‐alkylarylation of activated alkenes with an aryl C(sp2)H bond and a C(sp3)H bond adjacent to a ...heteroatom. This reaction is a new strategy for the synthesis of oxindoles and makes use of DBU as ligand and TBHP as oxidant (see scheme, TBHP=tert‐butyl hydrogenperoxide).
Display omitted
•Tide-driven flocculation dynamics in the Pearl River Estuary was quantified.•Microflocs dominate with variation caused mainly by flocculi–microfloc exchange.•Thresholds for distinct ...response to turbulence and concentration identified.•Halocline divides flocculation into two vertical layers.
Tide-dominated estuaries are often characterized by a high variability of turbulent shear, suspended particulate matter (SPM) concentration and salinity, which poses challenges for a comprehensive understanding of its mass transport including cohesive sediment dynamics. Here, a combined in situ and numerical study was undertaken to investigate the mechanism of flocculation during tidal cycles, with the aim to disentangle the impacts of turbulent shear, SPM concentration and salinity on flocs. Results show that microflocs (20–200 μm) dominate in the Pearl River Estuary and floc size variation is caused primarily by exchange between flocculi (4–20 μm) and microflocs. We also identified a critical shear rate (G* ≈ 5/s) below which floc exchange occurs slowly. Above the threshold, the particle size distribution is left-skewed and clustered below 60 μm. Evolutions of flocs with different initial sizes synchronize gradually to adapt to the local hydrological environment. The trends of floc size evolution and absolute net flocculation rates are similar among diverse tidal shear cycles. The reason can be attributed to the turbulent shear which enhances both aggregation and breakup processes, thereby limiting the floc size in a certain range. The higher the concentration, the larger both the particle size and the range of variation. In addition, results of numerical modelling reveal that the flocculation time for primary particles is inversely proportional to shear and concentration. A critical concentration (C* ≈ 50 mg/L), below which the impact of concentration on the equilibrium diameter of flocs is more than twice as strong as shear, whilst above which the equilibrium diameter is inversely proportional to the Kolmogorov microscale and weakly correlated to concentration, was also identified. Furthermore, halocline was found to increase vertical variation of flocs size, suggesting co-existence of different flocculation mechanisms across this layer.
A new anode strategy for accessing xanthen-9-azoles via an electrochemical C(sp3)–H/N–H cross-coupling of xanthenes with azoles is described. This reaction proceeds efficiently with a broad scope of ...both xanthenes and N–H-free azoles under metal- and additional oxidant-free conditions and represents a new access to direct incorporation of important N-heterocycle units into the resulting xanthenes.
In the past decade, extensive functionalization of diarylethene backbones has enabled these molecules to respond not only to light but also to other external stimuli and extended their applications ...to biological and materials sciences. In this review, the recent progress on diarylethene-based multi-responsive molecular switches is summarized with emphasis on the modulation of their photophysical properties by multiple external stimuli, their structure-property-function relationship, and their underlying operating principles.
This review highlights the recent research progress on diarylethene-based multi-responsive molecular switches with special emphasis on the modulation of their photophysical properties by multiple external stimuli.
A new iron‐facilitated silver‐mediated radical 1,2‐alkylarylation of styrenes with α‐carbonyl alkyl bromides and indoles is described, and two new C−C bonds were generated in a single step through a ...sequence of intermolecular C(sp3)−Br functionalization and C(sp2)−H functionalization across the alkenes. This method provides an efficient access to alkylated indoles with broad substrate scope and excellent selectivity.
Bridging alkene: An intermolecular arene C(sp2)−H functionalization strategy is established for the radical 1,2‐alkylarylation of styrenes with α‐carbonyl alkyl bromides and indoles using iron as the catalyst and silver as the promotor. This method enables the formation of two C−C bonds in a single reaction. acac=acetylacetonate.
PDF
