Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel-Hauser amides, and magnesium alkoxides

Expeditious preparation of β-sec-alkyl vicinal amino alcohols used for chiral ligand synthesis

An economical route providing quick access to chiral β-amino alcohols bearing one β-sec-alkyl group was developed. This protocol starts with commercially available and cheap chiral sources such as derivatives of L-serine and L-threonine. A series of vicinal amino alcohols with high optical purity were prepared in good yields through 4 or 6 operationally simple steps. Two different strategies (three routes) were designed for the synthesis of amino alcohols bearing β-sec-alkyl groups with various steric hindrance.

In Situ Grignard Metalation Method for the Synthesis of Hauser Bases

The in situ Grignard Metalation Method (iGMM) is a straightforward one‐pot procedure to quickly produce multigram amounts of Hauser bases R₂N‐MgBr which are valuable and vastly used metalation reagents and novel electrolytes for magnesium batteries. During addition of bromoethane to a suspension of Mg metal and secondary amine at room temperature in an ethereal solvent, a smooth reaction yields R₂N‐MgBr under evolution of ethane within a few hours. A Schlenk equilibrium is operative, interconverting the Hauser bases into their solvated homoleptic congeners Mg(NR₂)₂ and MgBr₂ depending on the solvent. Scope and preconditions are studied, and side reactions limiting the yield have been investigated. DOSY NMR experiments and X‐ray crystal structures of characteristic examples clarify aggregation in solution and the solid state.