Search results for "MBI"

2020

Teraryl-based alpha-helix mimetics have resulted in efficient inhibitors of protein-protein interactions (PPIs). Extending the concept to even longer oligoarene systems would allow for the mimicking of even larger interaction sites. We present a highly efficient synthetic modular access to quateraryl alpha-helix mimetics, in which, at first, two phenols undergo electrooxidative dehydrogenative cross-coupling. The resulting 4,4′-biphenol is then activated by conversion to nonaflates, which serve as leaving groups for iterative Pd-catalyzed Suzuki-cross-coupling reactions with suitably substituted pyridine boronic acids. This work, for the first time, demonstrates the synthetic efficiency of …

Formation and trapping of the thermodynamically unfavoured inverted-hemicucurbit[6]uril

2019

Amplification of a thermodynamically unfavoured macrocyclic product through the directed shift of the equilibrium between dynamic covalent chemistry library members is difficult to achieve. We show for the first time that during condensation of formaldehyde and cis-N,N'-cyclohexa-1,2-diylurea formation of inverted-cis-cyclohexanohemicucurbit[6]uril (i-cis-cycHC[6]) can be induced at the expense of thermodynamically favoured cis-cyclohexanohemicucurbit[6]uril (cis-cycHC[6]). The formation of i-cis-cycHC[6] is enhanced in low concentration of the templating chloride anion and suppressed in excess of this template. We found that reaction selectivity is governed by the solution-based template-a…

Electrochemical Arylation Reaction

2018

Arylated products are found in various fields of chemistry and represent essential entities for many applications. Therefore, the formation of this structural feature represents a central issue of contemporary organic synthesis. By the action of electricity the necessity of leaving groups, metal catalysts, stoichiometric oxidizers, or reducing agents can be omitted in part or even completely. The replacement of conventional reagents by sustainable electricity not only will be environmentally benign but also allows significant short cuts in electrochemical synthesis. In addition, this methodology can be considered as inherently safe. The current survey is organized in cathodic and anodic con…

Efficient and simple synthesis of novel 1,2,3-triazolyl-linked benzimidazolone, molecular docking and evaluation of their antimicrobial activity

2020

In this study, a novel series of 1,2,3-triazolyl-benzimidazolone derivatives have been synthesized by click reaction of azides with benzimidazolones 2a–b. The latter compounds were prepared with excellent yields (85–97%), the structures of products were determined by spectral analysis. Then, the X-rays crystallographic analysis of compound 7a revealed the self-assembling properties. The new heterocycles were evaluated for their in vitro antimicrobial activities against Gram-positive and Gram-negative bacteria and against fungi strains. The most tested synthesized compounds showed potent antibacterial and antifungal activities against all tested strains. The compound 6c was found to be the m…

Total Synthesis of (-)-Oxycodone via Anodic Aryl-Aryl Coupling.

2019

A fully regio- and diastereoselective electrochemical 4a–2′-coupling of a 3′,4′,5′-trioxygenated laudanosine derivative enables the synthesis of the corresponding morphinandienone. This key intermediate is further transformed into (−)-oxycodone through conjugate nucleophilic substitution for E-ring closure and [4 + 2] cycloaddition with photogenerated singlet oxygen to accomplish diastereoselective hydroxylation at C-14. The anodic transformation provides high yields and can be performed under constant current conditions both in a simple undivided cell or in continuous flow.

Room-Temperature Phosphorescence and Efficient Singlet Oxygen Production by Cyclometalated Pt(II) Complexes with Aromatic Alkynyl Ligands

2020

The synthesis of five novel cyclometalated platinum(II) compounds containing five different alkynyl-chromophores was achieved by the reaction of the previously synthesized Pt–Cl cyclometalated compound (1) with the corresponding RC≡CH by a Sonogashira reaction. It was observed that the spectral and photophysical characteristics of the cyclometalated platinum(II) complexes (Pt–Ar) are essentially associated with the platinum-cyclometalated unit. Room-temperature emission of the Pt–Ar complexes was attributed to phosphorescence in agreement with DFT calculations. Broad nanosecond (ns)-transient absorption spectra were observed with decays approximately identical to those obtained from the emi…

Thiourea-Catalyzed Domino Michael–Mannich [3+2] Cycloadditions: A Strategy for the Asymmetric Synthesis of 3,3′-Pyrrolidinyl-dispirooxindoles

2017

The asymmetric synthesis of trifluoromethylated 3,3′-pyrrolidinyl-dispirooxindole derivatives with four contiguous stereogenic centers, including two vicinal spiro-stereocenters, is described. Employing a bifunctional thiourea catalyst, a domino Michael–Mannich [3+2] cycloaddition occurs readily between isatin ketimines and isatin-derived enoates with good yields and very high stereoselectivities, providing a direct entry to the title compounds of potential medical value.

Microporous Triptycene‐Based Affinity Materials on Quartz Crystal Microbalances for Tracing of Illicit Compounds

2019

Triptycene-based organic molecules of intrinsic microporosity (OMIMs) with extended functionalized π-surfaces are excellent materials for gas sorption and separation. In this study, the affinities of triptycene-based OMIM affinity materials on 195 MHz high-fundamental-frequency quartz crystal microbalances (HFF-QCMs) for hazardous and illicit compounds such as piperonal and (-)-norephedrine were determined. Both new and existing porous triptycene-based affinity materials were investigated, resulting in very high sensitivities and selectivities that could be applied for sensing purposes. Remarkable results were found for safrole - a starting material for illicit compounds such as ecstasy. A …

The Chemo- and Stereoselective Formation of Pallado- and Platinocryptophanes

2019

International audience

Volcanic structures investigation through SAR and seismic interferometric methods: The 2011-2013 Campi Flegrei unrest episode

2019

Observations from satellites provide high-resolution images of ground deformation allowing to infer deformation sources by developing advanced modeling of magma ascent and intrusion processes. Nevertheless, such models can be strongly biased without a precise model of the internal structure of the volcano. In this study, we jointly exploited two interferometric techniques to interpret the 2011–2013 unrest at Campi Flegrei caldera (CFc). The first is the Interferometric Synthetic Aperture Radar (InSAR) technique, which provides highly-resolved spatial and temporal images of ground deformation. The second is the Ambient Noise Tomography (ANT), which images subsurface structures, providing the…