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As imple and rapid methodf or the selective synthesis of 3-(organylselanyl)-1 H-indoles and3 -(organylselanyl)imidazo[1,2-a]pyridines catalyzed by CuI/SeO 2 under ultrasound irradiation was developed. This protocol employs adiverse range of 1 H-indoles or imidazo[1,2-a]pyridines and diorganyl diselenides to afford the corresponding products selectively in good to excellent yields. Moreover,t he antioxidant activity of these compounds was evaluated by using aw ider ange of in vitro assays,s uch as 2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1picrylhydrazyl (DPPH) radical, ferric ion reducing antioxidant power (FRAP), and inhibition of reactive speciesf ormation in mice cortex. The bioassays revealed thatb oth classes of the newly synthesized organoselenium compounds present antioxidanta ctivity,w ith emphasis on the 3-(organylselanyl)-1 Hindoles.T his pharmacological activity opens aw ide range of biological applications where the reduction of oxidative stress is essential.[a] B. Results and DiscussionAc omparatives tudy on the use of microwaves, US, and conventional heating in the copper-catalyzed selenylation of indoles in DMSO was recently reported by us. [18b] In this reaction, Figure 1. 3-Arylselanylindoles A and B and 3-thioimidazo[1,2-a]pyridines C and D with similar effects to Combretastatin A-4a nd Enviroxime.Scheme1.Generalscheme of the present work.

Abstract:We describe here an efficient and regioselective synthesis of arylselanyl anilines by coppercatalyzed direct arylselenation of arylamines. Using a catalytic amount of copper iodide in dimethyl sulfoxide at 110 8C under an air atmosphere, a range of arylselanyl anilines was obtained directly from substituted diaryl diselenides in moderate to good yields via C À H bond cleavage of aryl amines.

Here we present our results in palladium cross-coupling reaction of aryl boronic acids with 4-iodo-2,3-dihydroselenophene derivatives. The cross-coupled products were obtained in satisfactory yields. A dehydrogenation of 4,5-diphenyl-2,3-dihydroselenophene was activated by DDQ and the 2,3-diarylselenophene was obtained in good yield. Regarding the antioxidant activity, the selenophene derivative 3a was effective in counteracting lipid and protein oxidation as well as scavenging ABTS radical. The findings of the present study indicate that 3a is a prototype for future drug development programs to treat disorders mediated by reactive oxygen species.

We described herein our results on the silver-catalyzed synthesis of diaryl selenides via a cross-coupling reaction of diaryl diselenides with aryl boronic acids. The methodology is tolerant to electron-donor and electron-withdrawing groups at the substrates and the desired products were obtained in good to excellent yields.

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Organocatalytic enamine-azide [3 + 2] cycloadditions between β-keto sulfones and aryl azides can be performed at room temperature in good to excellent yields of products in the presence of catalytic amounts of pyrrolidine (5 mol %). The proposed organocatalytic methodology was found to be applicable to β-keto arylsulfones containing a range of substituents. A wide variety of aryl azides also work. Basically, this constitutes a remarkably efficient protocol for the synthesis of novel 1,2,3-triazole compounds.