Unexpected transalkylation on 3-alkyl-2-alkylthio-1,3,4-thiadiazolium-5-thiolates: a computational and experimental mechanistic study.
5-Alkylthio-3-methyl-2-thioxo-1,3,4-thiadiazolines have been obtained on heating alkyl 1-methyl-1-hydrazinecarbodithioates with CS(2). A DFT-based computational mechanistic study suggests an initial pseudopericyclic [1,4]H shift as a key step, as well as the intermediacy of the otherwise expected isomers 2-alkylthio-3-methyl-1,3,4-thiadiazolium-5-thiolates, from which the final products are formed by stepwise S,S-transalkylation.
Departamento de Química Orgánica, Facultad de Química, Campus de Espinardo, Universidad de Murcia, E-30100 Murcia, Spain. artuesp@um.es
Arturo
A
Espinosa
Rafaela
R
García
Pedro
P
Molina
Alberto
A
Tárraga
D000478:Alkylation; D011789:Quantum Theory; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013830:Thiadiazoles / Q000138:chemical synthesis / Q000737:chemistry*
D013438:Sulfhydryl Compounds; D013830:Thiadiazoles