Ligand Design and Preparation, Photophysical Properties, and Device Performance of an Encapsulated-Type -Tris(heteroleptic) Iridium(III) Emitter.

The organic molecule 2-(1-phenyl-1-(pyridin-2-yl)ethyl)-6-(3-(1-phenyl-1-(pyridin-2-yl)ethyl)phenyl)pyridine () has been designed, prepared, and employed to synthesize the encapsulated-type -tris(heteroleptic) iridium(III) derivative Ir(κ-'L). Its formation takes place as a result of the coordination of the heterocycles to the iridium center and the -CH bond activation of the phenyl groups. Dimer [Ir(μ-Cl)(η-COD)] is suitable for the preparation of this compound of class [Ir(9h)] (9h = 9-electron donor hexadentate ligand), but Ir(acac) is a more appropriate starting material.

-Tris(heteroleptic) Red Phosphorescent Iridium(III) Complexes Bearing a Dianionic ,,','-Tetradentate Ligand.

1-Phenyl-3-(1-phenyl-1-(pyridin-2-yl)ethyl)isoquinoline (HMeL) has been prepared by Pd(-XantPhos)-catalyzed "" to synthesize new phosphorescent red iridium(III) emitters (601-732 nm), including the carbonyl derivative Ir(κ--,'--,'-MeL)Cl(CO) and the acetylacetonate compound Ir(κ--,'--,'-MeL)(acac). The tetradentate 6e-donor ligand (6tt') of these complexes is formed by two different bidentate units, namely, an orthometalated 2-phenylisoquinoline and an orthometalated 2-benzylpyridine. The link between the bidentate units reduces the number of possible stereoisomers of the structures [6tt' + 3b] (3b = bidentate 3e-donor ligand), with respect to a [3b + 3b' + 3b″] emitter containing three free bidentate units, and it permits a noticeable stereocontrol.

Phosphorescent Iridium(III) Complexes with a Dianionic C,C',N,N'-Tetradentate Ligand.

To prepare new phosphorescent iridium(III) emitters, 2-phenyl-6-(1-phenyl-1-(pyridin-2-yl)ethyl)pyridine (HL) has been designed and its reactions with [Ir(μ-Cl)(η-COD)] (, COD = 1,5-cyclooctadiene) have been studied. The products obtained depend on the refluxing temperature of the solvent. Thus, complexes Ir(κ-'-L)Cl(CO) (), [Ir(η-COD)(κ-HL)][IrCl(η-COD)] (), and [Ir(μ-Cl)(κL)] () have been formed in 2-ethoxyethanol, propan-2-ol, and 1-phenylethanol, respectively.

Chiral 2-Aminobenzimidazole as Bifunctional Catalyst in the Asymmetric Electrophilic Amination of Unprotected 3-Substituted Oxindoles.

The use of readily available chiral -cyclohexanediamine-benzimidazole derivatives as bifunctional organocatalysts in the asymmetric electrophilic amination of unprotected 3-substituted oxindoles is presented. Different organocatalysts were evaluated; the most successful one contained a dimethylamino moiety (). With this catalyst under optimized conditions, different oxindoles containing a wide variety of substituents at the 3-position were aminated in good yields and with good to excellent enantioselectivities using di--butylazodicarboxylate as the aminating agent.

Readily Available Chiral Benzimidazoles-Derived Guanidines as Organocatalysts in the Asymmetric α-Amination of 1,3-Dicarbonyl Compounds.

The synthesis and the evaluation as organocatalysts of new chiral guanidines derived from benzimidazoles in the enantioselective α-amination of 1,3-dicarbonyl compounds using di--butylazodicarboxylate as aminating agent is herein disclosed. The catalysts are readily synthesized through the reaction of 2-chlorobezimidazole and a chiral amine in moderate-to-good yields. Among all of them, those derived from ()-1-phenylethan-1-amine () and ()-1-(2-naphthyl)ethan-1-amine () turned out to be the most efficient for such asymmetric transformation, rendering good-to-high yields and moderate-to-good enantioselectivities for the amination products.