Search results for "DERIVATIVES"

Designing P-Chirogenic 1,2-Diphosphinobenzenes at Both P-Centers Using P(III)-Phosphinites

2016

International audience; A new enantiodivergent synthesis of P-chirogenic 1,2-diphosphinobenzenes (DP*B) bearing the chirality on one or both phosphorus centers is reported using aryne chemistry. The principle is based on successive reactions of 1,2-dibromobenzene with sec-phosphide boranes, then DABCO to remove the borane, and finally with chlorophosphines or P(III)-chirogenic phosphinites. The efficiency of this synthesis was demonstrated by the stereoselective preparation of (S,S)-1,2-bis(o-anisylphenylphosphino)benzene. A comparison of DIPAMP and homochiral DP*B ligands in asymmetric Rh- or Pd-catalyzed reactions was reported.

Kohn-Sham Decomposition in Real-Time Time-Dependent Density-Functional Theory An Efficient Tool for Analyzing Plasmonic Excitations

2017

The real-time-propagation formulation of time-dependent density-functional theory (RT-TDDFT) is an efficient method for modeling the optical response of molecules and nanoparticles. Compared to the widely adopted linear-response TDDFT approaches based on, e.g., the Casida equations, RT-TDDFT appears, however, lacking efficient analysis methods. This applies in particular to a decomposition of the response in the basis of the underlying single-electron states. In this work, we overcome this limitation by developing an analysis method for obtaining the Kohn-Sham electron-hole decomposition in RT-TDDFT. We demonstrate the equivalence between the developed method and the Casida approach by a be…

A simple HPLC assay for polyamines and their monoacetylderivatives

1993

(2-Pyridyl)sulfonyl Groups for ortho -Directing Palladium- Catalyzed Carbon-Halogen Bond Formation at Functionalized Arenes

2017

International audience; We describe an efficient palladium-catalyzed selective C-H ortho-monohalogenation (X=I, Br, Cl, F) of various functionalized (2-pyridyl) aryl-sulfones. ortho-, meta-and para-functionalization is tolerated at the arene group which undergoes C-H halogenation. Some modifications are also possible on the 2-(arylsulfonyl) heteroaryl directing groups. A comparison of the halogenation efficiency suggests that bromination is the practical method of choice, while chlorination and fluorination are possible but more challenging. Under forcing conditions ortho-dihalogenation can also be achieved.

Synthesis, Electrochemistry, and Photophysics of Aza-BODIPY Porphyrin Dyes

2016

International audience; The synthesis of dyad and triad aza-BODIPY-porphyrin systems in two steps starting from an aryl-substituted aza-BODIPY chromophore is described. The properties of the resulting aza-BODIPY-porphyrin conjugates have been extensively investigated by means of electrochemistry, spectroelectrochemistry, and absorption/emission spectroscopy. Fluorescence measurements have revealed a dramatic loss of luminescence intensity, mainly due to competitive energy transfer and photoinduced electron transfer involving charge separation followed by recombination.

I credit derivatives nell’economia dei sistemi finanziari tra innovazione e criticità

2011

Il lavoro è volto a comprendere il ruolo degli strumenti credit derivatives nell’economia dei sistemi finanziari. I credit derivatives rappresentano una significativa forma di innovazione finanziaria che incide direttamente sull’attività degli intermediari finanziari e, in particolare, bancari. Il ricorso al mercato dei credit derivatives rende possibile il trasferimento integrale o parziale dei rischi di credito senza il contestuale trasferimento delle singole esposizioni creditizie. Ciò dischiude una varietà di scelte aziendali di de-integrazione della catena del valore dell’intermediazione creditizia e di diversificazione del portafoglio crediti che, tuttavia, non sempre conducono ad una…

Efficacy and safety of photodynamic therapy with RLP068 for diabetic foot ulcers: a review of the literature and clinical experience

2020

This article is the second part of a literature review concerning diabetic foot ulcers (DFUs) and the use of antimicrobial photodynamic therapy (PDT). PDT involves the topical application of a photosensitiser into the tissue, followed by illumination that induces the formation of reactive oxygen species (ROS). PDT provides bacterial inactivation and promotes wound healing, and it can be used to manage the infection and microbial colonisation of DFUs. It has pivotal advantages in comparison with chemotherapeutics, such as no potential to induce resistance, and a wide spectrum of activity. Tetracationic Zn(II) phthalocyanine derivatives have been developed for PDT. Among these, we would like …

Discovery of a new class of sortase a transpeptidase inhibitors to tackle gram-positive pathogens: 2-(2-phenylhydrazinylidene)alkanoic acids and rela…

2016

A FRET-based random screening assay was used to generate hit compounds as sortase A inhibitors that allowed us to identify ethyl 3-oxo-2-(2-phenylhydrazinylidene)butanoate as an example of a new class of sortase A inhibitors. Other analogues were generated by changing the ethoxycarbonyl function for a carboxy, cyano or amide group, or introducing substituents in the phenyl ring of the ester and acid derivatives. The most active derivative found was 3-oxo-2-(2-(3,4dichlorophenyl)hydrazinylidene)butanoic acid (2b), showing an IC50 value of 50 µM. For a preliminary assessment of their antivirulence properties the new derivatives were tested for their antibiofilm activity. The most active compo…

Thiazole Analogues of the Marine Alkaloid Nortopsentin as Inhibitors of Bacterial Biofilm Formation

2020

Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 a…

The Impact of a 1,2,3-Triazole Motif on the Photophysical Behavior of Non-K Tetrasubstituted Pyrene with a Substitution Pattern Providing the Long Ax…

2022

1,3,6,8-Tetrasubstituted pyrene derivatives with two types of substituents (4-(2,2-dimethylpropyloxy)pyridine, 1-decyl-1,2,3-triazole, 1-benzyl-1,2,3-triazole, and pyrazole), substituted in such a way that provides the long axial symmetry, are prepared and characterized in the present study. To the best of our knowledge, the pyrene derivative containing the same heteroaryl motif (triazole) but substituted by two various alkyls, straight decyl and benzyl-based side chains (C), is reported for the first time. For comparison, compounds with one kind of triazole motif and substituted pyridine or pyrazole groups were prepared (A and B). The photophysical properties of all molecules were evaluate…