New Interventions by silicone grease in synthesis

Abstract In redox‐transmetallation protolysis (RTP) reactions in tetrahydrofuran (thf) between excess scandium or cerium metal, Hg(C 6 F 5 ) 2 and 3,5‐dimethylpyrazole (Me 2 pzH) in silicone greased Schlenk flasks, formation of the 3,5‐dimethyl‐1‐pyrazolyl(dimethyl)siloxide (Me 2 pzSiMe 2 O) ligand was observed. Thus the former reaction gave [Sc 2 (Me 2 pz) 4 (Me 2 pzSiMe 2 O) 2 ] 1 in good yield, whilst the latter gave a mixture of [Ce 4 O(Me 2 pz) 9 (Me 2 pzSiMe 2 O) 2 ] 2 a , [Ce 4 O(Me 2 pz) 11 ] 2 b , both mixed oxidation state species, and the Ce IV complex [Ce(Me 2 pz) 4 (Me 2 pzH)] 2 c .