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

Abstract

Application of the diamide, diimine {-CHN(1,2-C6H4)N(2,6-iPr2-C6H3)}2m ((dadi)m) ligand to titanium provided adducts (dadi)TiLx (1-Lx; Lx = THF, PMe2Ph, (CNMe)2), which possess the redox formulation [(dadi)4-]Ti(iv)Lx, and 22 πe- (4n + 2). Related complexes containing titanium-ligand multiple bonds, (dadi)TiX (2X; X = O, NAd), exhibit a different dadi redox state, [(dadi)2-]Ti(iv)X, consistent with 20 πe- (4n). The Redox Non-Innocence (RNI) displayed by dadim impedes binding by CO, and permits catalytic conversion of AdN3 + CO to AdNCO + N2. Kinetics measurements support carbonylation of 2NAd as the rate determining step. Structural and computational evidence for the observed RNI is provided.