Reagent and Catalyst Capsules: A Chemical Delivery System for Reaction Screening and Parallel Synthesis
Niginia Borlinghaus, Johannes Kaschel, Johanna Klee, Vanessa Haller, Jasmin Schetterl, Stephanie Heitz, Tanja Lindner, Justin Dietrich, Wilfried M. Braje, Anaïs Jolit
Abstract
Commercially available hydroxypropyl methylcellulose capsules are employed as a fast, safe, and user-friendly chemical delivery system containing all reagents (catalyst, ligand, and base) for three important transition-metal-catalyzed reactions: Buchwald-Hartwig, Suzuki-Miyaura, and metallophotoredox C-N cross-coupling reactions. This encapsulation methodology simplifies the screening of reaction conditions and the preparation of compound libraries using parallel synthesis in organic solvents or aqueous media. These reagents-containing HPMC capsules are easy to prepare, come in different sizes, and can be stored on the bench under noninert conditions.