Regio- and Stereoselective Addition of Selenium Dihalogeeides to Propargyl Halogenides

摘要

It is known that selenium dibromide and dichloride cannot be isolated in pure form and that in aprotic solvents the former exists in an equilibrium with Se2Br2 and bromine, and the latter with Se2Cl2 and SeCl4. However, we have found that freshly prepared selenium dibromide and dichloride can be used as selective electrophilic reagents in the synthesis of organoselenium compounds. The reactions of selenium halogenides with acetylene, diethynyl-silanes, diethynylgermanes, divinyl sulfide, divinyl sulfone, and divinyl selenide have been systematically studied.