Reaction of selenothioic acid S-alkyl esters with electron deficient alkynes: Selective synthesis of cyclic selenides and acyclic divinyl selenides
摘要:
The reaction of selenothioic acid S-alkyl esters with electron deficient alkynes was carried out under reflux in toluene to give cyclic selenides in good yields. On the contrary, the similar reaction in MeOH or CH2Cl2 with Et(3)N afforded acyclic divinyl selenides in good to high yields.
The reaction of lithium alkyneselenolates generated from lithium alkynides and selenium powder with a variety of thiols afforded selenothioic acid S-alkyl esters in moderate to high yields. The product yields were highly dependent on the substituents of the starting acetylenes. The formation of unstable S-aryl ester was confirmed by the enolization followed by alkylation.