Imine hydrogenation with simple alkaline earth metal catalysts

Hydrogenation of unsaturated bonds is dominated by transition metal catalysis. Compared with transition metals, the use of other metals is less explored, especially so for the s -block elements despite their ready availability and low cost. Here, we show that group 2 metal amides (M[N(SiMe 3 ) 2 ] 2 , M = Mg, Ca, Sr, Ba) unexpectedly catalyse the hydrogenation of aldimines with H 2 at 80 °C and a remarkably low H 2 pressure of 1–6 bar. Conversion rates increase with metal size: Mg