Mononuclear complexes of a tridentate redox-active ligand with sulfonamido groups: structure, properties, and reactivity

Abstract

Enhancing the redox properties of FeII with a bis(sulfonamido)amine pincer ligand leads to catalytic cyclic amination reactivity.

Molecular and Supramolecular Multiredox Systems

“…Borovik et al., reported the synthesis of Fe(II) salt H5 (Scheme ), where the redox active ligand binds with the metal through the three anionic nitrogen, while the other coordination sites were occupied by 2,2′‐bipyridine . The complex H5 exhibits attractive electronic properties with three oxidations at −0.94 V, −0.15 V, +0.60 V and one reduction at −2.09 V vs Fe/Fe + .…”

“…Borovik et al, reported the synthesis of Fe(II) salt H5 (Scheme 5), where the redox active ligand binds with the metal through the three anionic nitrogen, while the other coordination sites were occupied by 2,2'-bipyridine. [54] The complex H5 exhibits attractive electronic properties with three oxidations at À 0.94 V, À 0.15 V, + 0.60 V and one reduction at À 2.09 V vs Fe/ Fe + . In addition, they also explored the catalytic activity of X towards the CÀ H activation of aryl azides at aliphatic and benzylic carbon centres for intramolecular amination reaction, resulting in moderate to good yields of indoline products.…”

Catalytic β C–H amination via an imidate radical relay

“…Among recent advances toward directed sp 3 C–H functionalization of abundant alcohol derivatives,4 there remain few methods to synthesize β amino alcohols (a privileged motif in medicine)5 by C–H amination 6. To complement state-of-the-art, metal-catalyzed nitrenoid and C–H insertion pathways for remote C–H amination,7 we sought to employ a radical-based approach that entails δ selective, hydrogen atom transfer (HAT) 8,9. Despite recent advances in δ C–H amination via HAT,10 there remain few catalytic examples of this transformation 11.…”

Stabilizing a NiII-aqua complex via intramolecular hydrogen bonds: Synthesis, structure, and redox properties

“…Another design aspect of redox-active ligands is the incorporation of functional groups to control the secondary coordination sphere around the metal ion(s). [1,19–21] Examples include the pincer ligands of Gilbertson that contain appended amine groups that form intramolecular hydrogen bonds (H-bonds) with external ligands. We have recently introduced a new redox-active ligand ([ibaps] 3− ) that contains a bis(aminophenyl)aminate ([NNN] 3− ) framework and shows rich redox properties when coordinated to Fe and Ga ions.…”

“…We have recently introduced a new redox-active ligand ([ibaps] 3− ) that contains a bis(aminophenyl)aminate ([NNN] 3− ) framework and shows rich redox properties when coordinated to Fe and Ga ions. [14,15,21] This ligand also has the potential to control the secondary coordination sphere around the metal ion through the formation of H-bonds involving the two appended sulfonamido groups. In this report, we describe the preparation of [Ni II (ibaps)(OH2)] − and its structural and redox properties.…”