An Under-Appreciated Source of Reproducibility Issues in Cross-Coupling: Solid-State Decomposition of Primary Sodium Alkoxides in Air

The decomposition of primary sodium alkoxide salts under ambient storage conditions and the effects of this phenomenon on commonly employed transition-metal-catalyzed cross-coupling reactions are described. By utilizing NMR, IR, and Raman spectroscopy, along with a modified Karl Fischer analysis, the main inorganic degradants were characterized, and CO₂ in the air was found to be a critical reactant within the decomposition process. The effects of storage conditions on decomposition were evaluated, and the preliminary experiments to understand the kinetics of this process were performed.