title: Efficient low-cost preparation oftrans-cyclooctenes using a simplified flow setup for photoisomerization.
abstract: Bioorthogonal ligations have emerged as highly versatile chemical tools for biomedical research. The exceptionally fast reaction between 1,2,4,5-tetrazines andtrans-cyclooctenes (TCOs), also known as tetrazine ligation, is frequently used in this regard. Growing numbers of applications for the tetrazine ligation led to an increased demand for TCO compounds, whose commercial availability is still very limited. Reported photochemical procedures for the preparation of TCOs using flow chemistry are straightforward and high yielding but require expensive equipment. Within this contribution, we present the construction and characterization of a low-cost flow photoreactor assembled from readily accessible components. Syntheses of all commonly usedtrans-cyclooctene derivatives were successfully carried out using the described system. We are convinced that the presented system for photoisomerization will promote access to bioorthogonally reactive TCO derivatives.
authors.affiliation: Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria ; Institute of Chemical Technologies and Analytics, TU Wien, Vienna, Austria.
authors.forename: Dennis
authors.initials: D
authors.lastname: Svatunek
authors.affiliation: Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Denk
authors.affiliation: Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
authors.forename: Veronika
authors.initials: V
authors.lastname: Rosecker
authors.affiliation: Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sohr
authors.affiliation: Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Hametner
authors.affiliation: Institute of Chemical Technologies and Analytics, TU Wien, Vienna, Austria.
authors.forename: Günter
authors.initials: G
authors.lastname: Allmaier
authors.affiliation: Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Fröhlich
authors.affiliation: Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
authors.forename: Hannes
authors.initials: H
authors.lastname: Mikula
keywords: Alkenes; Bioorthogonal chemistry; Click chemistry; Cycloadditions; Isomerization; Photochemistry