Redox non-innocence permits catalytic nitrene carbonylation by (dadi)Ti[double bond, length as m-dash]NAd (Ad = adamantyl)

Abstract

Application of the diamide, diimine {-CH[double bond, length as m-dash]N(1,2-C₆H₄)N(2,6-ⁱPr₂-C₆H₃)}₂ ^m ((dadi) ^m ) ligand to titanium provided adducts (dadi)TiL _x (1-L _x ; L _x = THF, PMe₂Ph, (CNMe)₂), which possess the redox formulation [(dadi)^4-]Ti(iv)L _x , and 22 πe^- (4n + 2). Related complexes containing titanium-ligand multiple bonds, (dadi)Ti[double bond, length as m-dash]X (2 [double bond, length as m-dash]X; 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 dadi ^m impedes binding by CO, and permits catalytic conversion of AdN₃ + CO to AdNCO + N₂. Kinetics measurements support carbonylation of 2 [double bond, length as m-dash]NAd as the rate determining step. Structural and computational evidence for the observed RNI is provided.