title: The Eschenmoser coupling reaction under continuous-flow conditions.
abstract: The Eschenmoser coupling is a useful carbon-carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yields. We have used a flow chemistry system to promote the Eschenmoser coupling under enhanced reaction conditions in order to convert the demanding precursors such as S-alkylated secondary thioamides and thiolactames in an efficient way. Under pressurized reaction conditions at about 220 °C, the desired Eschenmoser coupling products were obtained within 70 s residence time. The reaction kinetics was investigated and 15 examples of different building block combinations are given.
authors.affiliation: Institute for Chemistry and Biotechnology, Technische Universität Ilmenau, Weimarerstr. 32, D-98693-Ilmenau.
authors.forename: Sukhdeep
authors.initials: S
authors.lastname: Singh
authors.forename: J Michael
authors.initials: JM
authors.lastname: Köhler
authors.forename: Andreas
authors.initials: A
authors.lastname: Schober
authors.forename: G Alexander
authors.initials: GA
authors.lastname: Groß