Mechanochemically Activated Liebeskind–Srogl (L-S) Cross-Coupling Reaction: Green Synthesis of meso-Substituted BODIPYs

• Published in: Organometallics 2020-07, Vol.39 (14), p.2561-2564
• Main Authors: Pérez-Venegas, Mario, Villanueva-Hernández, Miriam N, Peña-Cabrera, Eduardo, Juaristi, Eusebio
• Format: Article
• Language: English
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/acs.organomet.0c00037

In the past decade mechanochemistry has become a highly versatile solvent-free methodology that fulfills several principles of so-called green chemistry. In this regard, we describe a mechanochemical activation protocol for the synthesis of several relevant meso-aryl-substituted BODIPYs via the Liebeskind–Srogl cross-coupling reaction with excellent yield and very short reaction times relative to alternative procedures in solution, thereby avoiding the use of bulk solvent. In contrast with previous assertions that the L-S reaction requires anaerobic conditions to avoid the oxidation of Cu­(I) to Cu­(II), our results seem to indicate that this paradigm may not be altogether accurate, since the L-S reactions studied here took place under aerobic conditions, possibly suggesting an alternative reaction mechanism.