Redox non-innocence permits catalytic nitrene carbonylation by (dadi)Ti=NAd (Ad = adamantyl)

Application of the diamide, diimine {-CH=N(1,2-C6H4)N(2,6-Pr-i(2)-C6H3)}(2)(m) ((dadi)(m)) ligand to titanium provided adducts (dadi)TiLx (1-L-x; L-x = THF, PMe2Ph, (CNMe)(2)), which possess the redox formulation [(dadi)(4-)]Ti(IV)L-x, and 22 pi e(-) (4n + 2). Related complexes containing titanium-ligand multiple bonds, (dadi)Ti=X (2=X; X = O, NAd), exhibit a different dadi redox state, [(dadi)(2-)]Ti(IV)X, consistent with 20 pi e(-) (4n). The Redox Non-Innocence (RNI) displayed by dadi(m) impedes binding by CO, and permits catalytic conversion of AdN(3) + CO to AdNCO + N-2. Kinetics measurements support carbonylation of 2=NAd as the rate determining step. Structural and computational evidence for the observed RNI is provided.