Selenoimidoylation of alcohols with selenium and isocyanides and its application to the synthesis of selenium-containing heterocycles

The reaction of alcohols with selenium and isocyanides in the presence of DBU gave oxyimidoylselenoates 6. Trapping of 6 with BuI resulted in high-yield formation of selenocarbonimidates 4. When alk-2-yn-1-ols 9 were allowed to react with selenium and isocyanides under similar conditions, new selenium-containing heterocycles 10, 2-imino-4-alkylidene-1,3-oxaselenolanes, were obtained via cycloaddition of oxyimidoylselenoates 13 generated in situ by intramolecular addition of selenolates to carbon-carbon triple bonds.