title: Multicomponent domino reactions of hydrazinecarbodithioates: concise access to 3-substituted 5-thiol-1,3,4-thiadiazolines.
abstract: Two classes of addition/cycloaddition cascade reactions of hydrazinecarbodithioate (1) have been developed under mild reaction conditions. Reaction of hydrazinecarbodithioate (1) with formaldehyde solution (2) and propiolic acid (3) gives 3-propargyl-5-thiol-2,3-dihydro-1,3,4-thiadiazoles (5) via a decarboxylative coupling/cycloaddition domino sequence. When propiolic acid (3) is switched to phenyl boronic acid (4), a petasis/cycloaddition domino reaction is instead observed, in which 3-benzyl-5-thiol-2,3-dihydro-1,3,4-thiadiazoles (6) are obtained. Both these reactions show a wide range of functional-group compatibility for propiolic acids and aryl boronic acids, and give the corresponding products in moderate to good yields.
authors.affiliation: College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, 333 Longteng Road, Shanghai, 201620, China. sungaris@gmail.com.
authors.forename: Huihui
authors.initials: H
authors.lastname: Jia
authors.forename: Huangdi
authors.initials: H
authors.lastname: Feng
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Sun
mesh_terms: D000480:Alkynes / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry; D006834:Hydrazines / Q000138:chemical synthesis / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D011422:Propionates / Q000737:chemistry; D012996:Solutions; D013830:Thiadiazoles / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000480:Alkynes; D001897:Boronic Acids; D006834:Hydrazines; D008670:Metals; D011422:Propionates; D012996:Solutions; D013830:Thiadiazoles; C011537:propiolic acid