Structures and Reactions of 1,3-Diamidodilithium Complexes: the Hemisolvated l-[CMe2{CHMeN(R)}2Li2·OEt2], the Unsolvated 1:1 Mixed Organo-amidolithium u-[CMe2{CHMeN(R′)}2·Li2·(nBuLi)2], and the Product of Oxidative Ring Closure, the Pyrazolidine l-[(RNCHMe)2CMe2] (R = 2-iPr-C6H4; R′ = 2,6-iPr2-C6H3)

The hemi‐solvated C2‐symmetric 1,3‐diamidolithium l‐[CMe2{CHMeN(R)}2Li2·OEt2] has been crystallographically characterized. It reacts with oxygen to form the N‐N ring‐closed pyrazolidine l‐[(RNCHMe)2CMe2]. The slightly bulkier Cs‐symmetric amidolithium u‐[CMe2{CHMeN(R′)}2·Li2] forms an unsolvated 1:2 heterocubane complex with nBuLi in the solid state and in solution, as determined by X‐ray crystallography and multinuclear NMR spectroscopy (R = 2‐iPr‐C6H4; R′ = 2,6‐iPr2‐C6H3). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)