Thierry Terme

Organic Electron Donors as Powerful Single-Electron Reducing Agents in Organic Synthesis

One-electron reduction is commonly used in organic chemistry for the formation of radicals by the stepwise transfer of one or two electrons from a donor to an organic substrate. Besides metallic reagents, single-electron reducers based on neutral organic molecules have emerged as an attractive novel source of reducing electrons. The past 20 years have seen the blossoming of a particular class of organic reducing agents, the electron-rich olefins, and their application in organic synthesis. This Review gives an overview of the different types of organic donors and their specific characteristics in organic transformations.

Functionalization of 6-Nitrobenzo(1,3)dioxole with Carbonyl Compounds via TDAE Methodology

We report herein the synthesis of substituted 2-(6-nitrobenzo[1,3]dioxol-5-yl)-1-aryl ethanols and 2-(6-nitrobenzo[1,3]dioxol-5-yl)-propionic acid ethyl esters from the reaction of 5-chloromethyl-6-nitrobenzo[1,3]dioxole with various aromatic carbonyl and α-carbonyl ester derivatives using the tetrakis(dimethylamino)ethylene (TDAE) methodology.

Influence of Silver Nanoparticles on 2,3-Bis(Chloromethyl)Anthracene-1,4,9,10-Tetraone

Size effect of silver nano particles on the photophysical properties of 2,3-bis(chloromethyl)anthracene-1,4,9,10-tetraone (BCMAT) have been investigated using optical absorption and fluorescence emission techniques. Silver NPs of different sizes have been prepared by two different methods. Quenching of fluorescence of BCMAT has been found to increase with decrease in the size of the silver NPs. Stern–Volmer quenching constants have also been calculated.

A novel benzonitrile analogue inhibits rhinovirus replication

OBJECTIVES To study the characteristics and the mode of action of the anti-rhinovirus compound 4-[1-hydroxy-2-(4,5-dimethoxy-2-nitrophenyl)ethyl]benzonitrile (LPCRW_0005). METHODS The antiviral activity of LPCRW_0005 was evaluated in a cytopathic effect reduction assay against a panel of human rhinovirus (HRV) strains. To unravel its precise molecular mechanism of action, a time-of-drug-addition study, resistance selection and thermostability assays were performed. The crystal structure of the HRV14/LPCRW_0005 complex was elucidated as well. RESULTS LPCRW_0005 proved to be a selective inhibitor of the replication of HRV14 (EC(50) of 2 ± 1 μM). Time-of-drug-addition studies revealed that LPCRW_0005 interferes with the earliest stages of virus replication. Phenotypic drug-resistant virus variants were obtained (≥30-fold decrease in susceptibility to the inhibitory effect of LPCRW_0005), which carried either an A150T or A150V amino acid substitution in the VP1 capsid protein. The link between the mutant genotype and drug-resistant phenotype was confirmed by reverse genetics. Cross-resistance studies and thermostability assays revealed that LPCRW_0005 has a similar mechanism of action to the capsid binder pleconaril. Elucidation of the crystal structure of the HRV14/LPCRW_0005 complex revealed the existence of multiple hydrophobic and polar interactions between the VP1 pocket and LPCRW_0005. CONCLUSIONS LPCRW_0005 is a novel inhibitor of HRV14 replication that acts as a capsid binder. The compound has a chemical structure that is markedly smaller than that of other capsid binders. Structural studies show that LPCRW_0005, in contrast to pleconaril, leaves the toe end of the pocket in VP1 empty. This suggests that extended analogues of LPCRW_0005 that fill the full cavity could be more potent inhibitors of rhinovirus replication.

RAPID SYNTHESIS OF NEW AZAHETEROCYCLIC HYDROXYMALONATE DERIVATIVES USING TDAE APPROACH

- A new series of azaheterocyclic hydroxymalonate derivatives was synthesized from reaction between chloromethyl azaheterocycles and diethyl oxomalonate using tetrakis(dimethylamino)ethylene (TDAE).

Synthesis of New Active Sulfones in the 5-Nitroimidazole Series

We describe here the preparation of new 5-nitroimidazoles which are known to have an efficacy against metronidazole-susceptible and -resistant Giarda, Trichomonas, and Entamoeba spp. The multi-step synthesis uses electron transfer methodology.

Original synthesis of tetraalkylquinones by poly-SRN1 reactions

A series of complex and highly branched quinones were obtained by reacting an original tetraalkylating agent, 2,3,5,6-tetrachloromethyl-1,4-benzoquinone with primary or secondary nitroalkanes under SRN1 reactions conditions. # 2000 Elsevier Science Ltd. All rights reserved.

Synthesis of Novel Highly Functionalized 4-Thiazolidinone Derivatives from 4-Phenyl-3-thiosemicarbazones

We present herein the synthesis in good yields of two series of highly functionalized thiazolidinone derivatives from the reactions of various 4-phenyl-3-thio-semicarbazones with ethyl 2-bromoacetate and diethyl acetylenedicarboxylate, respectively.

Synthesis of New Quinoxalines Containing an Oxirane Ring by the TDAE Strategy and in Vitro Evaluation in Neuroblastoma Cell Lines

Neuroblastoma is an aggressive pediatric malignancy with significant chemotherapeutic resistance. In order to obtain new compounds active on neuroblastoma cell lines, we investigated the reactivity of carbanion formed via TDAE in quinoxaline series. The new synthesized compounds were tested for their anti-proliferative activity on two neuroblastoma cell lines, and seven oxirane derivatives obtained interesting activities.

Polymerization Initiated by Organic Electron Donors

Polymerization reactions with organic electron donors (OED) as initiators are presented herein. The metal-free polymerization of various activated alkene and cyclic ester monomers was performed in short reaction times, under mild conditions, with small amounts of organic reducing agents, and without the need for co-initiators or activation by photochemical, electrochemical, or other methods. Hence, OED initiators enabled the development of an efficient, rapid, room-temperature process that meets the technical standards expected for industrial processes, such as energy savings, cost-effectiveness and safety. Mechanistic investigations support an electron-transfer initiation pathway that leads to the reduction of the monomer.