Base‐Catalyzed Hydration of Silicon‐Containing Activated Alkynes: The Effect of Substituents at the Triple Bond

Water as a Reactant: DABCO-Catalyzed Hydration of Activated Alkynes for the Synthesis of Divinyl Ethers

A practical and efficient addition of water to readily available activated alkynes delivering divinyl ethers is reported. The reaction proceeds with full atom economy in a very straightforward experimental procedure. Additionally, of all the tertiary amines studied to catalyze the reaction, the best and most efficient is clearly DABCO (1,4-diazabicyclo[2.2.2]octane). Finally, the solvent choice is crucial for the efficiency of this process and we have found that the reaction is best performed in wet dichloromethane for propiolic esters and alkynones, and in wet acetonitrile for propiolamides.

Regio- and Stereoselective Synthesis of (Z,Z)-Bis(3-amino-3-oxo-1-propenyl) Selenides and Diselenides Based on 2-propynamides: A Novel Family of Diselenides with High Glutathione Peroxidase-like Activity

The efficient regio- and stereoselective syntheses of (Z,Z)-bis(3-amino-3-oxo-1-propenyl) selenides and diselenides in high yields based on the nucleophilic addition of sodium selenide to 2-propynamides and sodium diselenide to 3-(trimethylsilyl)-2-propynamides have been developed. The first examples of the addition of a selenium-centered nucleophile to 2-propynamides with a terminal triple bond and diselenide anion to 3-(trimethylsilyl)-2-propynamides have been carried out. Bis(3-amino-3-oxo-1-propenyl) diselenides are a novel family of compounds, none of which has yet been described in the literature. The glutathione peroxidase-like activity of the obtained compounds has been evaluated and products with high activity have been found. It was established that diselenides are superior to selenides with the same substituents in glutathione peroxidase-like activity. The results of the structural studying of products by single-crystal X-ray diffraction analysis and 77Se-NMR data are discussed.

Hydrogen Bonding-directed Sequential 1,6/1,4-Addition of Heteroatom Nucleophiles onto Electron-deficient 1,3-Diynes

The hydrogen bonding-directed sequential 1,6/1,4-additions developed herein allow for creating unique heterocycles with structural diversity under mild conditions without using metal catalysts or organometallic reagents.

(Z,Z)-Selanediylbis(2-propenamides): Novel Class of Organoselenium Compounds with High Glutathione Peroxidase-Like Activity. Regio- and Stereoselective Reaction of Sodium Selenide with 3-Trimethylsilyl-2-propynamides

The efficient regio- and stereoselective synthesis of (Z,Z)-3,3'-selanediylbis(2-propenamides) in 76-93% yields was developed based on the reaction of sodium selenide with 3-trimethylsilyl-2-propynamides. (Z,Z)-3,3'-Selanediylbis(2-propenamides) are a novel class of organoselenium compounds. To date, not a single representative of 3,3'-selanediylbis(2-propenamides) has been described in the literature. Studying glutathione peroxidase-like properties by a model reaction showed that the activity of the obtained products significantly varies depending on the organic moieties in the amide group. Divinyl selenide, which contains two lipophilic cyclohexyl substituents in the amide group, exhibits very high glutathione peroxidase-like activity and this compound is considerably superior to other products in this respect.