Preparation and Structure of Iminopyrrolyl and Amidopyrrolyl Complexes of Group 2 Metals

Reactions of N -aryliminopyrrolyl ligand 1a, 2-(2,6- i Pr 2 C 6 H 3 N═CH)-C 4 H 3 NH (Imp Dipp -H), with dibenzylcalcium gave two types of pyrrolylcalcium complexes, bis(iminopyrrolyl)calcium ( 2a ) and (amidopyrrolyl)calcium ( 3a ), via alkane elimination and ligand alkylation reaction, respectively. Preparation of a mono(iminopyrrolyl) complex, (iminopyrrolyl)Ca[N(SiMe 3 ) 2 ](THF) 2 ( 4a ), was accomplished by the addition of 1 equiv of 1a to Ca[N(SiMe 3 ) 2 ] 2 (THF) 2 . A series of group 2 metal bis(iminopyrrolyl) complexes, [(Imp Dipp ) 2 M(THF) 3 ] (M = Sr ( 5a ), Ba, ( 6a )) and [(Imp Me ) 2 Ca(THF) 2 ] ( 2b ) (2-(4-MeC 6 H 4 N═CCH 3 )-C 4 H 3 NH (Imp Me -H)), was selectively prepared via amine elimination reactions, and their molecular structures were clarified by X-ray diffraction studies.