Thieme Chemistry Journal Awardees - Where Are They Now? [3]-Cumulenes, Sulfanyl-Substituted Butadienes, and Functionalized Thiophenes Starting from Polypyridinium Salts

Abstract

Hexachlorobuta-1,3-diene reacted with DMAP, 4-(pyrrolidin-1-yl)pyridine, 4-(morpholin-1-yl)pyridine, and 4-amino-pyridine to 1,1',1,1'-tetrakis-(2,3-dichlorobuta-1,3-diene-1,1,4,4-tetrayl)pyridinium salts, respectively. Except for the 4-amino derivative, these salts were converted into 1,1'-bis-(1,2,3,4-tetrachloro-buta-1,3-diene-1,4-diyl)pyridinium salts on treatment with bromine or iodine in acetic acid or water. On reaction with thiolates, tetrakis-sulfanyl-substituted [3]-cumulenes were obtained, whereas treatment with sulfur yielded 1,1'-bis-(2,3-dichloro-thiophene-1,4-diyl)pyridinium salts. Sodium disulfide gave 1,1'-bis-(2,3-dichloro-1,4-dimercaptobuta-1,3-diene-1,4-diyl)pyridinium salts.