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}Li-2(TMEDA)(3)] (1), {[mu-eta(5)-2- [ CH3CH2NCH2] C4H3N]Li-2(TMEDA)}(2) (2), {[Pris eta(5):eta(1)-2-[(CH3)(3)CNCH2]C4H3N]Li-2(TMEDA)}(2) (3), {[eta(5)-2-[(CH3)(2)CHNCH2]C4H3N]Li-2 (TMEDA)}(2) (4), and {[eta(5)-2-[(CH2)(5)CHNCH2]C4H3N1Li2(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.