title: Near-Infrared Photoinduced Coupling Reactions Assisted by Upconversion Nanoparticles.
abstract: We introduce nitrile imine-mediated tetrazole-ene cycloadditions (NITEC) in the presence of upconversion nanoparticles (UCNPs) as a powerful covalent coupling tool. When a pyrene aryl tetrazole derivative (λabs, max =346 nm) and UCNPs are irradiated with near-infrared light at 974 nm, rapid conversion of the tetrazole into a reactive nitrile imine occurs. In the presence of an electron-deficient double bond, quantitative conversion into a pyrazoline cycloadduct is observed under ambient conditions. The combination of NITEC and UCNP technology is used for small-molecule cycloadditions, polymer end-group modification, and the formation of block copolymers from functional macromolecular precursors, constituting the first example of a NIR-induced cycloaddition. To show the potential for in vivo applications, through-tissue experiments with a biologically relevant biotin species were carried out. Quantitative cycloadditions and retention of the biological activity of the biotin units are possible at 974 nm irradiation.
authors: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George St, Brisbane, QLD, 4001, Australia.|Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76131, Karlsruhe, Germany.|Institut für Biologische Grenzflächen, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
authors: Paul
authors: P
authors: Lederhose
authors: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128, Mainz, Germany.
authors: Zhijun
authors: Z
authors: Chen
authors: Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76131, Karlsruhe, Germany.|Institut für Biologische Grenzflächen, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
authors: Rouven
authors: R
authors: Müller
authors: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George St, Brisbane, QLD, 4001, Australia. j.blinco@qut.edu.au.
authors: James P
authors: JP
authors: Blinco
authors: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128, Mainz, Germany. wusi@mpip-mainz.mpg.de.
authors: Si
authors: S
authors: Wu
authors: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George St, Brisbane, QLD, 4001, Australia. christopher.barner-kowollik@kit.edu, christopher.barnerkowollik@qut.edu.au.|Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76131, Karlsruhe, Germany. christopher.barner-kowollik@kit.edu, christopher.barnerkowollik@qut.edu.au.|Institut für Biologische Grenzflächen, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany. christopher.barner-kowollik@kit.edu, christopher.barnerkowollik@qut.edu.au.
authors: Christopher
authors: C
authors: Barner-Kowollik
keywords: NITEC; near infrared; photoinduced cycloaddition; polymer coupling; upconversion