The Radicals cAAC Me ·AlR ₂ (thf) (R = Me, Et) as Synthons for Aluminum(II)-Centered Radicals AlR ₂

The iodoalanes cAAC Me ·AlR 2 I (cAAC Me {= 1-(2,6-di- iso -propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene}; R = Me, 2 Me; Et, 2 Et ) were prepared and used as precursors for the synthesis of the corresponding aluminyl radicals cAAC Me ·AlR 2 (thf) (R = Me, 3 Me; Et, 3 Et ). Characterization by EPR spectroscopy and SC-XRD, as well as DFT calculations revealed 3 to be mainly cyclic (alkyl)(amino)carbene (cAAC)-centered radicals. 3 Me and 3 Et are rare examples of radicals in the coordination sphere of aluminum and are rare examples of persistent synthons for aluminum(II)-centered radicals. Dissociation of the thf ligand was investigated experimentally, i.e., the exchange of the stabilizing Lewis base and scavenging the radical with organic substrates, and by means of DFT calculations. This dissociation process is a key step in the radical reactivity of 3 and the results reveal the ability of 3 to react as an aluminum-centered radical.