Lewis Base Assisted Magnesium Complexes Incorporating Pyrrolyl and Ketiminate Ligands: Synthesis, Structural Diversity and Characterization

A series of four, five and six‐coordinated magnesium derivatives integrating with substituted pyrrole and ketimine ligands are conveniently synthesized. Reaction of two equiv of 2‐dimethylaminomethyl pyrrole with Mg[N(SiMe 3 ) 2 ] 2 in THF affords the monomeric magnesium complex Mg[C 4 H 3 N(2‐CH 2 NMe 2 )] 2 (THF) 2 ( 1 ) in high yield along with elimination of two equiv of HN(SiMe 3 ) 2 . Similarly, the reaction between two equiv of 2‐t‐butylaminomethyl pyrrole and Mg[N(SiMe 3 ) 2 ] 2 in THF renders the magnesium derivative, Mg[C 4 H 3 N(2‐CH 2 NH t Bu)] 2 (THF)2 2 ( 2 ) in good yield. Interestingly, reaction between two equiv of 2‐t‐butylaminomethyl pyrrole and Mg[N(SiMe 3 ) 2 ] 2 in toluene, instead of THF, generates Mg[C 4 H 3 N(2‐CH2NH t Bu)] 2 ( 3 ), also in high yield. Furthermore, the assembly of two equiv of ketimine ligand, HOCMeCHCMeNAr (Ar = C 6 H 3 ‐2,6‐ i Pr 2 ) and Mg[N(SiMe 3 ) 2 ] 2 , yields five‐coordinated magnesium derivatives, Mg(OCMeCHCMeNAr) 2 (THF) ( 4 ) and Mg(OCMeCHCMeNAr) 2 (OEt 2 ) ( 5 ), using THF and diethyl ether, respectively. All the aforementioned derivatives are characterized by 1 H and 13 C NMR spectroscopy as well as 1 , 3 , 4 and 5 are subjected to X‐ray diffraction analysis in solid state.