A Novel Electromagnetic Mill Promoted Mechanochemical Solid-State Suzuki–Miyaura Cross-Coupling Reactions: Ultra-Low Catalyst Loading without Molecular Dispersants

Abstract The Nobel-prize-winning Suzuki-Miyaura cross-coupling(SMC) is a practical and attractive strategy for the construction of C-C bonds in both academic and industrial settings. However, the development of solid-state SMC reactions remains extremely scarce. Herein, we report the first electromagnetic mill(EMM) promoted solid-state SMC reaction using ultra-low palladium loading(0.05 mol%) without any molecular dispersants. This protocol exhibits substantially broadened substrate scope, good functional groups tolerance and efficient gram-scale synthesis, especially, provides relative high yields. The utility of this strategy was exemplified in the modification of photoluminescence molecules, cross-coupling of slightly soluble compound and synthesis of several important bioactive molecules. Furthermore, the XPS analyses on the oxidation state changes of palladium catalyst suggest the involvement of PdI intermediate which might be the active catalytic species. This solvent-free solid-state EMM-SMC was potential developed into industrially attractive and environmentally friendly routes, and the EMM system developed in this study could unlock broad areas of chemical space for solvent-free solid-state metal-catalyzed syntheses of valuable targets in various scientific fields.