Luminescence and reactivity of 7-azaindole derivatives and complexes

Abstract

7-Azaindole and its derivatives have been extensively investigated for uses in biological probes and imaging. In contrast, there have been very limited studies on the coordination chemistry and the applications of 7-azaindole and derivatives in materials science and in chemical bond activation. Our recent research has shown that 7-azaindolyl and derivatives are excellent blue emitters for organic light emitting diodes, they have rich coordination chemistry with both main group elements and transition metal ions, and their metal complexes display not only phosphorescence but also unusual and often unprecedented reactivity toward C-H and C-X bonds. This critical review discusses recent advances in these fields with focuses on new 7-azaindolyl derivatives and their metal complexes developed by our group. The luminescent properties and applications of 7-azaindolyl-based compounds will be presented. The reactivity of Pt(II) complexes toward C-H and C-X bonds, especially the steric impact of the bis(7-azaindolyl) chelate ligands and bimetallic cooperativity will be discussed (86 references).

Homoleptic Transition Metal Complexes of the 7-Azaindolide Ligand Featuring κ1-N1 Coordination

“…18-28 In very few instances have transition metal complexes featuring exclusive κ 1 -N1 coordination been reported, 29-31 although this coordination mode is better established for main group metals such as aluminum. 32-34 In addition to binding to metals in its neutral and deprotonated forms, the 7-azaindole moiety has also been incorporated into a variety of chelating ligands. 35-37 In such complexes, coordination is again primarily observed through the N7 atom.…”

In Vitro Antitumor Active Gold(I) Triphenylphosphane Complexes Containing 7-Azaindoles

“…In this work, we report on new complexes of the general composition [Au( n aza)(PPh 3 )] ( 1 – 8 ) containing the N 1-deprotonated, C2-, C3-, C4-, and/or C5-substituted 7-azaindole-based ligands ( n aza; Figure 1). 7-Azaindole itself (i.e., unsubstituted; Haza), as well as its halogeno-derivatives used in this work, are known as suitable ligands for various transition metal complexes [23,24], where they mostly act as electroneutral N 7-coordinated ligand (e.g., [Pt(ox)(Haza) 2 ], cis -[Pt( 3Cl Haza) 2 Cl 2 ] or [( η 6 - p -cym)Ru(Haza)Cl 2 ]; ox = oxalate(2–), p -cym = p -cymene) [25,26,27] or N 1-monodentate- (e.g., [Au(aza)(PPh 3 )]; 1 in this work), or N 1, N 7-bidentate-coordinated (e.g., [Cu 2 (μ-aza) 4 (dmf) 2 ]) N 1-deprotonated 7-azaindolate anions [28,29]. …”

Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

“…Particularly, several 7-azaindoles (1 H -pyrrole[2,3- b ]pyridine) [1–4], including 4-substituted compounds [5–8] have found applications in various therapeutic areas. Despite their utility in various drug-development programs in academic research and the pharmaceutical industry, methods for the synthesis of this class of compounds and functionalization of 7-azaindole scaffolds remain limited [9].…”