Synthesis of a Borylated Ibuprofen Derivative through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions

J Vis Exp. 2022 Nov 30:(189). doi: 10.3791/64571.

Abstract

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common drugs used to manage and treat pain and inflammation. In 2016, a new class of boron functionalized NSAIDs (bora-NSAIDs) was synthesized under mild conditions via the copper-catalyzed regioselective boracarboxylation of vinyl arenes using carbon dioxide (CO2 balloon) and a diboron reductant at room temperature. This original method was performed primarily in a glovebox or with a vacuum gas manifold (Schlenk line) under rigorous air-free and moisture-free conditions, which often led to irreproducible reaction outcomes due to trace impurities. The present protocol describes a simpler and more convenient benchtop method for synthesizing a representative bora-NSAID, bora-ibuprofen. A Suzuki-Miyaura cross-coupling reaction between 1-bromo-4-isobutylbenzene and vinylboronic acid pinacol ester produces 4-isobutylstyrene. The styrene is subsequently boracarboxylated regioselectively to provide bora-ibuprofen, an α-aryl-β-boryl-propionic acid, with good yield on a multi-gram scale. This procedure allows for the broader utilization of copper-catalyzed boracarboxylation in synthetic laboratories, enabling further research on bora-NSAIDs and other unique boron-functionalized drug-like molecules.

Publication types

  • Video-Audio Media
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes*
  • Anti-Inflammatory Agents, Non-Steroidal
  • Boron
  • Copper
  • Ibuprofen*

Substances

  • Alkenes
  • Ibuprofen
  • Boron
  • Copper
  • Anti-Inflammatory Agents, Non-Steroidal