Selenothioic acid S-alkyl esters were reacted with allylic bromides in the presence of Et3N. Mono-, di- or tri-allylatd products were selectively formed by changing reaction temperatures, times and allylic bromides used. The reaction proceeded with high regio- and stereoselectivity via the seleno-Claisen rearrangement. The selective synthesis of monoallylated esters was also attained by the reaction
Allylations of selenothioic acid S-alkyl esters with allylic bromides in the presence of Et3N in THF took place selectively at the α-position of selenocarbonyl group to give allylated products with high regio- and stereo-selectivity.
Selenothioic acid S-alkyl esters were synthesized from the reaction of terminal acetylenes with n-butyllithium, selenium, and alkanethiols in moderate to high yields. The use of substituted benzenethiols or (triphenylsilyl)acetylene allowed for the isolation of S-aryl esters. The synthesis of α-aryl selenothioic acid S-alkyl esters was attained by the acid-catalyzed reaction of selenoacetic acid Se-alkynyl
Selenothioic acid S-alkyl esters were treated with Et3N and Cd(OAc)2·2H2O to give symmetrically substituted selenophenes, whereas the similar reaction in the presence of alkyl halides afforded ketene selenothioacetals in moderate yields.