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 ,'-dicyclohexylcarbodiimide (CyN═C═NCy), triphenylphosphine oxide (PhP═O), and benzophenone (PhCO). These crystallographically characterized compounds could be regarded as model intermediates en route to reducing the N═C, P═O, and C═O bonds of unsaturated substrates. Heteroleptic NacNacMg(TMP) intriguingly functions as a TMP nucleophile both with -BuNCO and -BuNCS, producing a urea or thiourea derivative respectively attached to Mg, though the NacNac ligand in the former reaction also engages noninnocently with a second -BuNCO molecule via insertion at the reactive NacNac backbone γ-carbon site.