Unique effects of sulfur and water on the syntheses of thiaheterocycles
作者:Dong-Qing Sun、Jing-Kui Yang
DOI:10.1002/hc.20755
日期:——
A series of thiaheterocycles were produced by the reaction of diethyl 2,3-dibromomaleate or diethyl 2,3-dibromofumarate with different sulfides without any catalyst. The major products shifted in different conditions. Water was found playing a key role in the generation of carbon–carbon single bonds. Meanwhile, the addition of sulfur could accelerate the reaction and greatly improve the yield of certain
4-dithiins was developed using sulfur and alkynes. A rhodium complex catalyzes the additionreaction of sulfur with cyclic alkynes giving the corresponding symmetrical 1,4-dithiines under reflux conditions in 2-butanone. Unsymmetrical 1,4-dithiins are synthesized by the reaction of sulfur with dialkyl acetylenedicarboxylates in the presence of cyclic alkynes or vinyl ethers. A convenient synthetic method