49 research outputs found
A rapid efficient microwave-assisted synthesis of a 3',5'-pentathymidine by copper(I)-catalyzed [3+2] cycloaddition.
No full textInternational audienceStarting from 5?-O-tosylthymidine, sequential azidation and Cu-catalyzed [3+2] azide?alkyne 1,3-dipolar cycloaddition led to the formation of a 3?,5?-pentathymidine in high yield. The whole process needed only work-up/precipitation steps and was completed within just 18min, thanks to microwave activation
Substituted tubaic acids, new oxidative rotenoid metabolites from Lonchocarpus nicou
No full textInternational audienc
Chelation-controlled regioselective alkylation of pyrimidine 2'-deoxynucleosides.
No full textInternational audienceProtection-deprotection steps, which are usually needed for regioselective alkylation of pyrimidine deoxynucleosides, can be avoided by choosing the appropriate solvent. The combined effects of low dielectric constant and possible sodium chelation by pyrimidine nucleosides may account for the unexpected regioselectivity observed in THF
Design of a new oligotriazole peptide nucleic acid analogue (oT-PNA)
No full textInternational audienceWe describe in this Letter the synthesis of an original thymine azido-heterotrimer generated by Click Chemistry. This trimer has been obtained from an azido-thymidine and a new chloroethyl-propargylated PNA monomer analogue, after two azidation/click-reaction cycles. Conformational preferences of a rotameric intermediate have also been studied
First Example of a Heptazine-Porphyrin Dyad; Synthesis and Spectroscopic Properties
No full textWe have prepared the first example of a porphyrin linked to an heptazine photoactive antenna. The two entities, linked with an alkyl spacer, demonstrate the activity of both active moieties. While they behave electrochemically independantly, on the other hand the spectroscopy shows the existence of energy transfer between both partners
Synthesis of a New Bichalcone via Suzuki–Miyaura Coupling Reaction
No full textInternational audienceUnlike the wide number of natural biflavonoids, natural bichalcones are a rare and even less studied class. Nevertheless, some of them have proved their interest in the fight against cancer through their cytotoxic activity against human tumor cell lines. The aim of this study was to synthesize a novel bichalcone: 3′,3‴,4,4′,4″,4‴,5′,5‴-octamethoxy-2,3″-bichalcone 1. The most efficient synthetic pathway was the Suzuki–Miyaura reaction between a boronated chalcone and a brominated one
