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The last decade has witnessed significant progress in the development of novel synthetic methods for the preparation of a variety of new functionalized and condensed compounds via reactions of organic dichalcogenides with acetylenic derivatives. The present review highlights recent developments in the synthesis of organoselenium compounds based on the reactions of organic diselenides with acetylenes over the past few years. The discussion mainly focuses on the literature data for the last 5 years. It is worth noting that the lion's share of this material is devoted to catalytic and electrophile-mediated reactions with aromatic compounds, containing a triple bond and nucleophilic functional groups. [ABSTRACT FROM AUTHOR]

First examples of the reactions of 3-trimethylsilyl-2-propynamides with organic diselenides yielding 3-alkylselanyl-2-propenamides and 3-organylselanyl-2-propynamides were realized. The latter compounds were obtained by the Cu-catalyzed reaction of organic diselenides with 4-propioloylmorpholine. The reaction of 3-trimethylsilyl-2-propynamides with dialkyl diselenides in the system NaBH4/H2O/K2CO3/THF proceeded in a regio- and stereoselective fashion, affording 3-alkylselanyl-2-propenamides in 90–94% yields. An unsymmetrical divinyl selenide with the cyclic amide groups and a product, containing two selanyl-2-propenamide moieties and three cyclic amide groups, were synthesized. The Cu-catalyzed allylation reaction of 3-trimethylsilyl-2-propynamides was accompanied with desilylation to yield 3-allyl-2-propynamides. [ABSTRACT FROM AUTHOR]

An efficient approach to a novel family of (Z)-3-amino-3-oxo-1-propenyl selenocyanates was developed based on the reaction of KSeCN with 3-trimethylsilyl-2-propynamides in the presence of ammonium chloride in methanol. The reaction was accompanied by a desilylation process. The products were not formed under the same reaction conditions in the absence of ammonium chloride, which was used for the first time in the reactions of selenocyanates with acetylenes. The use of this new methodology allowed the reaction to carry out in a regio- and stereoselective fashion as anti-addition affording vinyl selenocyanates with a (Z)-configuration in high yields. [ABSTRACT FROM AUTHOR]

The Pd/Cu-catalyzed Sonogashira reaction of (E,E)-bis(2-bromovinyl) selenide and (E,E)-bis(1-bromo-1-hexen-2-yl) selenide with terminal alkynes was found to proceed at room temperature involving both bromine atoms and the selanyl function. As a result, new bis-(1,3-enynyl) selenides and enediyne hydrocarbons are formed with a complete retention of the stereoconfiguration of the initial selenides. Due to steric hindrances in the cross-coupling at the selenyl function in the case of (E,E)-bis(1-bromo-1-hexen-2-yl) selenide, the second process is realized to a lesser extent than with unsubstituted (E,E)-bis(2-bromovinyl) selenide. [ABSTRACT FROM AUTHOR]

The catalytic regioselective and highly efficient synthesis of bis-1,2,3-triazole derivatives of 9-selenabicyclo[3.3.1]nonane was developed. The 1,3-dipolar cycloaddition reaction of 2,6-diazido-9-selenabicyclo[3.3.1]nonane with a variety of terminal acetylenes catalyzed by a copper acetate/sodium ascorbate system proceeded in a regioselective fashion, affording 2,6-bis(4-organyl-1,2,3-triazole)-9-selenabicyclo[3.3.1]nonanes in high yields (93–98%). The reaction of 2,6-diazido-9-selenabicyclo[3.3.1]nonane with dimethyl and diethyl acetylenedicarboxylates was carried out as thermal 1,3-dipolar Huisgen cycloaddition giving the corresponding 4,5-disubstituted 1,2,3-triazole derivatives of 9-selenabicyclo[3.3.1]nonane in high yields. The obtained products are potentially bioactive compounds and first representatives of selenium heterocycles combined with two 1,2,3-triazole moieties. 2.6-Diazido-9-selenabicyclo[3.3.1]nonane was obtained in quantitative yield via the reaction of sodium azide with 2,6-dibromo-9-selenabicyclo[3.3.1]nonane at room temperature. The latter compound was synthesized by stereoselective transannular addition of selenium dibromide to cis, cis-1,5-cyclooctadiene. [ABSTRACT FROM AUTHOR]