Expected and Unexpected Reactivities of Homoleptic LiNacNac and Heteroleptic NacNacMg(TMP) β-Diketiminates toward Various Small Unsaturated Organic Molecules.

Homoleptic LiNacNac forms simple donor-acceptor complexes with N,N’-dicyclohexylcarbodiimide (CyN=C=NCy), triphenylphosphine oxide (Ph3P=O) and benzophenone (Ph2CO). These crystallographically-characterized compounds could be regarded as model intermediates en route to reducing of the N=C, P=O and C=O bonds of unsaturated substrates. Heteroleptic NacNacMg(TMP) intriguingly functions as a TMP nucleophile both with t-BuNCO and t-BuNCS, producing a urea or thiourea derivative respectively attached to Mg, though the NacNac ligand in the former reaction also engages non-innocently with a second t-BuNCO molecule via insertion at the reactive NacNac backbone γ-carbon site.