Reaction of 3-aryl-2-cyanothioacrylamides with electron-deficient alkynes: synthesis of 4-aryl-4H-thiopyrans
Abstract
The 3-aryl-2-cyanothioacrylamides 2–4 react well with methyl propiolate and dimethyl acetylenedicarboxylate yielding the thiopyrans 8–13. Reactions with less activated alkynes proceed sluggishly, if at all.