2‑Aminopyrrolyl Dilithium Compounds: Synthesis, Structural Diversity, and Catalytic Activity for Amidation of Aldehydes with Amines

Five dilithium compounds containing bidentate dianionic pyrrolyl ligands, [{2-(CH3NCH2)­C4H3N}­Li2(TMEDA)3] (1), {[μ-η5-2-[CH3CH2NCH2]­C4H3N]­Li2(TMEDA)}2 (2), {[μ-η5:η1-2-[(CH3)3CNCH2]­C4H3N]­Li2(TMEDA)}2 (3), {[η5-2-[(CH3)2CHNCH2]­C4H3N]­Li2 (TMEDA)}2 (4), and {[η5-2-[(CH2)5CHNCH2]­C4H3N]­Li2(TMEDA)}2 (5), were synthesized, and their structural features were provided. Compounds 1–5 were proved to be a series of efficient catalysts for amidation reactions of aldehydes with amines in good to excellent yields under mild conditions.