Functionalization of 2,4-Dichloropyrimidines by 2,2,6,6-Tetramethylpiperidyl Zinc Base Enables Modular Synthesis of Antimalarial Diaminopyrimidine P218 and Analogues.

Two routes to the antimalarial diaminopyrimidine were developed based on the C-6 metalation of suitable 2,4-dichloro-5-alkoxy pyrimidines using (TMP)Zn·2MgCl·2LiCl base. One approach involves a late-stage modification of the C-6 position, while the other allows for tail fragment modification of . Both routes have proven reliable in synthesizing , as well as eight analogues.

Selenium as a Versatile Reagent in Organic Synthesis: More than Allylic Oxidation.

For many years since its discovery, Selenium has played the role of a bad boy who became a hero in organic transformations. Selenium dioxide, for instance, is one of the most remembered reagents in allylic oxidations, having been applied in the synthesis of several naturally occurring products. The main goal of this review is to show the recent advances in the use of classical and new selenium reagents in organic synthesis.

Synthesis of Isoxazolines by the Electrophilic Chalcogenation of β,γ-Unsaturated Oximes: Fishing Novel Anti-Inflammatory Agents.

Herein, we describe a new strategy to prepare chalcogen-functionalized isoxazolines. The strategy involves the reaction of β,γ-unsaturated oximes with electrophilic selenium and tellurium species, affording 19 new selenium- and tellurium-containing isoxazolines in good yields after 1 h at room temperature. The method was efficiently extended to the synthesis of 5 new (bis)isoxazoline ditellurides.

Preparation of Organic Nitrates from Aryldiazoacetates and Fe(NO)·9HO.

A thermal protocol is reported for the formal insertion of nitric acid into aryldiazoacetates using Fe(NO)·9HO. This strategy is mild and high yielding and allows the preparation of a large variety of members of an unprecedented family of organic nitrates. The nitrate group can be also readily transformed into other functional groups and heterocyclic moieties and can possibly allow new biological explorations of untapped potential associated with their NO-releasing ability.

Ultrasound-promoted copper-catalyzed synthesis of bis-arylselanyl chrysin derivatives with boosted antioxidant and anticancer activities.

Herein we report the use of ultrasonic irradiation (US) in the synthesis of six new semi-synthetic selenium-containing chrysin derivatives by a simple and effective methodology utilizing CuI as catalyst, in good to excellent yields (60-89%). It was observed that US accelerates the reaction compared to conventional heating with excellent selectivity for diselenylated products. Compounds were tested for their antioxidant and anticancer activities in vitro and it was observed that the presence of selenium in the A-ring of chrysin enhanced both antioxidant and anticancer properties.

Reduction of Selenoamides to Amines Using SmI-HO.

Selenoamides are selectively reduced to amines by SmI with HO. The process is general for primary, secondary, and tertiary aryl and alkyl selenoamide substrates and selectively delivers amine products. The reduction proceeds under mild conditions using SmI activated by straightforward addition of HO, and does not require an additional Lewis base additive.

Sonochemistry: An efficient alternative to the synthesis of 3-selanylindoles using CuI as catalyst.

Ultrasonic (US) irradiation was successfully used as an alternative energy source to prepare 3-selanylindoles through the direct selanylation of indoles with diorganyl diselenides using CuI (20 mol%) as catalyst and DMSO as the solvent. By using this US-promoted reaction, eleven 3-organylselanylindoles were prepared selectively and in good yields. A comparative study between the reactions under conventional heating, microwave and ultrasound irradiations was performed, and it was observed advantage in using US over the other heating systems.

A selenium-based ionic liquid as a recyclable solvent for the catalyst-free synthesis of 3-selenylindoles.

The ionic liquid 1-butyl-3-methylimidazolium methylselenite, [bmim][SeO2(OCH3)], was successfully used as solvent in the catalyst-free preparation of 3-arylselenylindoles by the reaction of indole with ArSeCl at room temperature. The products were obtained selectively in good yields without the need of any additive and the solvent was easily reused for several cycles with good results.