Sterically shielded primary anilides of the alkaline-earth metals of the type (thf)nAe(NH-Ar*)2 (Ae = Mg, Ca, Sr, and Ba; Ar* = bulky aryl)

Metalation of 2,4,6-triphenylphenylamine (H2N-C6H2-2,4,6-Ph-3, 1a) and 4-methyl-2,6-bis(diphenyl-methyl)aniline (2,6-bis(diphenylmethyl)-p-toluidine, H2N-C6H2-4-Me-2,6-(CHPh2)(2), 2a) with dibutylmagnesium and Ae[N(SiMe3)(2)](2) with a stoichiometric 1 : 2 ratio in THF at room temperature yields the corresponding primary anilides [(thf)(n)Ae{N(H)-C6H2-2,4,6-Ph-3}(2)] (Ae/n = Mg/2 (1b), Ca/2 (1c), Sr/3 (1d), and Ba/3 (1e)) and [(thf)(n)Ae{N(H)-C6H2-4-Me-2,6-(CHPh2)(2)}(2)] (Ae/n = Mg/2 (2b), Ca/3 (2c) and Sr/2 (2d)), respectively. The 1 : 1 reaction of Mg(n/sBu)(2) and MgPh2 with 2a leads to the formation of heteroleptic [(thf)(2)Mg(R){N(H)-C6H2-4-Me-2,6-(CHPh2)(2)}] (R = n/sBu (2b(Bu)), Ph (2b(Ph))). At 50 degrees C, the strontium complex 2d liberates one equivalent of 2a via intramolecular deprotonation of the triarylmethyl functionality yielding dinuclear [(thf)(2)Sr{N(H)-C6H2-4-Me-2-(CPh2)-6-(CHPh2)(2)}](2) (2d'). The barium compound is significantly more reactive and regardless of applied stoichiometry the isotypic barium congener [(thf)(2)Ba{N(H)-C6H2-4-Me-2-(CPh2)-6-(CHPh2)(2)}](2) (2e') forms. The molecular structures of 1c, 2d, 2d', and 2e'are stabilized by metal-phenyl pi-interactions.

Automated summary

In this study, metalation reactions of 2,4,6-triphenylphenylamine and 4-methyl-2,6-bis(diphenyl-methyl)aniline with different metal ligands were performed. The corresponding primary anilide compounds were successfully synthesized, and the reaction mechanisms were investigated. The results of this study are of great significance for understanding the synthesis and properties of metal complexes.