A new practical approach towards the synthesis of unsymmetric and symmetric 1,10-phenanthroline derivatives at room temperature

An efficient method towards synthesis of 1,10-phenanthrolines is described. Through Lewis acid-catalyzed annulation reaction between 3-ethoxycyclobutanones and 8-aminoquinolines, a variety of unsymmetric and symmetric 1,10-phenanthroline derivatives were readily prepared with high regioselectivity at room temperature.     

A new approach to the 1,10-phenanthroline core

A protocol for the synthesis of substituted 1,10-phenanthrolines is reported. The phenanthroline scaffold has been obtained constructing the central cycle starting from two pyridine rings. The method is hinged upon the intramolecular coupling of cis-1,2-di(2-bromo-3-pyridyl)ethenes that are in turn obtained from the Wittig reaction of 2-bromonicotinaldehydes with phosphonium salts prepared from 2-bromo-3-(bromomethyl)pyridines. Yields up to 75% have been obtained.     

Samarium-promoted coupling of 1,10-phenanthroline with carbonyl compounds for synthesis of new ligands

1,10-Phenanthroline reacts with aldehydes and ketones in the presence of samarium diiodide to produce 2-(1-hydroxyalkyl)-1,10-phenanthrolines. The hydroxyalkyl substituent can be functionalized in numerous ways or removed to permit further ligand variation. The carbonyl coupling reaction can also be repeated to provide 2,9-disubstituted phenanthrolines. Taken together, these operations provide ready access to a large number of phenanthroline derivatives to serve as ligand libraries for catalyst exploration.     

A rapid synthesis of asymmetric alkyl- and aryl-2,9-disubstitued 1,10-phenanthrolines

The finding that alkyl- and aryllithium reagents add almost instantly to the N-C2/C9 bond of 1,10-phenanthrolines led us to the development of a reaction scheme where the C2 and C9 positions of 1,10-phenanthroline can be functionalized by two different alkyl or aryl groups in a one-pot reaction. Furthermore, the total synthetic and work-up time needed for the entire transformation from unsubstituted 1,10-phenanthrolines into asymmetric 2,9-disubstituted 1,10-phenanthrolines was under 2 h and produced very high yields.     

Transformation of 2-alkoxyimidate-1,10-phenanthroline metal (Mn, Co and Ni) chlorides from bis(2-cyano-1,10-phenanthroline) metal chlorides: Syntheses, characterizations and their catalytic behavior toward ethylene oligomerization

The 2-alkoxyimidate-1,10-phenanthroline complexes of manganese, cobalt and nickel have been synthesized by the reaction of 2-cyano-1,10-phenanthroline with metal dichloride in the corresponding alcohol. The metal complexes bearing two 2-cyano-1,10-phenanthrolines were isolated in non-protonic solvent as the coordination around metal core with two ligands and two chlorides. The alkoxyimidation of nitrile linked on ligand was speeded in forming the 2-alkoxyimidate-1,10-phenanthrolinyl metal complexes. All the complexes have been characterized by FT-IR spectra and elemental analysis, and some of their structures have also been confirmed by single-crystal X-ray diffraction analysis. All the metal complexes were evaluated in the catalytic oligomerization of ethylene with some alkylaluminums as co-catalyst; in which manganese complexes were less active, cobalt complexes showed low to moderate activities, and nickel complexes gave moderate to good activities.     

Concave Reagents 36: Transition Metal Complexes With Concave 1,10-phenanthrolines

Complexes between concave 1,10-phenanthrolines 1 and transition metal ions (Mn 2+ , Fe 2+ , Fe 3+ , Co 2+ , Ni 2+ , Cu + , Cu 2+ , Zn 2+ , Ag + , Cd 2+ ) have been synthesized and characterized by various methods including UV titration, NMR spectroscopy, EPR spectroscopy, cyclovoltammetry, microanalysis and X-ray analysis. The concave 1,10-phenanthrolines 1 form 1:1 complexes with the metal ions while the complexes of analogous, but non-bimacrocyclic 1,10-phenanthrolines such as 2 and 2,9-dimethyl-1,10-phenanthroline exist in varying stoichiometries.     

Reactions of metal promoted C-C-coupling of coordinated 1,10-phenanthrolines in the synthesis of electron-rich d-element 1,10-phenanthrocyanines

The methods of C-C bond formation between free or coordinated 1,10-phenanthrolines are examined, and a new structural class of cyanine tetraazachromophores, the electron-rich d-element 1,10-phenanthrocyanines is presented, the role of metal promoted Csp2H-Csp2H coupling reactions in the synthesis of new metal 1,10-phenanthrocyanines is discussed.     

Alternative approaches to (Z)-1,2-bis(2-bromopyridin-3-yl)ethenes, key intermediates in the synthesis of the 1,10-phenanthroline core

A study on the synthesis of (Z)-1,2-bis(2-bromopyridin-3-yl)ethenes, key intermediates in the preparation of 1,10-phenanthrolines, based on selective Sonogashira and Suzuki-Miyaura cross-coupling reactions has been carried out.     

A simple synthesis of some 1,10-phenanthrolines

The reaction of o-phenylenediamine with α,β-unsaturated ketones in the presence of hydrochloric acid smoothly affords alkyl substituted 1,10-phenanthrolines in a one step synthesis.     

The synthesis of certain 4-mono- and 4,7 dihydroxy-1,10-phenanthrolines

Aminocrotonates and cinnamates formed by the action of ethyl acetoacetate and ethyl benzoylacetate on substituted 8-aminoquinolines have been cyclized to 4-hydroxy and 4,7-dihydroxy-1,10-phenanthrolines.     

The synthesis of polymethylquinolines and 1,10-phenanthrolines

Several polymethyl-1,10-phenanthrolines were synthesized by the use of 3-methyl-3-penten-2-one in Skraup reactions. The behavior of this ketone as well as that of 4-hydroxy-2-pentanone and 4-hydroxy-3-methyl-2-bulanone with various substituted anilines was studied.     

Preparation of Novel,Functionalized 1,10-Phenanthrolines

The preparation of hydrophilic 2,9-dialkyl-1,10-phenanthrolines, including phenanthroline-5-sulfonic acids and phenanthrolines with side chain functionality is described. Nucleophilic aromatic substitution chemistry is used to obtain regiochemically defined phenanthroline sulfonic acids by much simpler means than have been available in the past.     

Acid dissociation constants of mono- and diprotonated species of some polyalkyl substituted 1,10-phenanthrolines and the peculiar effects of 2,9-dialkyl substituents

Acid dissociation constants of protonated species of some selected polyalkyl substituted 1,10-phenanthrolines were determined spectrophotometrically. The results confirm the existence of diprotonated species and indicate that polyalkyl substituents enhance both protonation steps, but not necessarily to the same degree. A peculiar effect, presumably steric in nature, was discovered for the 2,9-dialkyl substituted derivatives which suggests that a different mode of protonation is involved for these than for other substituted 1,10-phenanthrolines.     

Cu(I) complexes of 3,3'-polymethylene bridged derivatives of 2,2'-bi-1,10-phenanthroline

A series of 3,3'-polymethylene-2,2'-bi-1,10-phenanthrolines coordinate with Cu(I) to form dinuclear complexes [(CuL)(2)](2+). As the 3,3'-bridge is lengthened from two to four carbons, the ligand becomes more twisted about the 2,2'-bond, favoring dinuclear coordination. The distance between the two copper atoms varies from 2.92 A for the dimethylene-bridged system to 3.59 A for the tetramethylene bridge. Favorable pi-stacking interactions occur between opposing ligands and promote complex formation. Competition experiments indicate that self-recognition is important and only homoleptic complexes are observed. Under equilibrium conditions, formation of the tetramethylene-bridged complex appears to be the most favored while the dimethylene-bridged system is least favored. The intensity of the long wavelength metal-ligand charge-transfer absorption band decreases as the 3,3'-bridge is shortened. Interaction between the two copper centers is evidenced by a splitting of the oxidation wave, and this splitting increases as the Cu-Cu distance is decreased.     

Synthesis of 5-isothiocyanato-1,10-phenanthroline

Reduction of 5-nitro-1,10-phenanthroline with hydrogen over Pd/C, followed by the treatment of 1,10-phenanthrolin-5-amine with thiophosgene in the presence of sodium acetate, gave 5-isothiocyanato-1,10-phenanthroline which is a thermally stable highly reactive ligand capable of quantitatively forming covalently bonded nanohybrid structures in a system transition metal complex-silica under mild conditions.     

Displacement reactions of 2-chloro- and 2,9-dichloro-1,10-phenanthroline: synthesis of a sulfur-bridged bis-1,10-phenanthroline macrocycle and a 2,2′-amino-substituted-bis-1,10-phenanthroline

The synthesis and structural assignments of 9-chloro-1,1-phenanthroline-2(1H)-thione and 1,10-dihydro-1,10-phenanthroline-2,9-dithione have been accomplished. The sulfur-bridged bis-1,10-phenanthroline macrocycle was readily prepared by heating the thione or equimolar amounts of the dithione and 2,9-dichloro-1,10-phenanthroline in diphenyl ether. Displacements of 2-chloro- or 2,9-dichloro-1,10-phenanthroline with N,N-dimethylethylenediamine afforded the corresponding amine and diamino analogues. An amino-substituted-2,2′-bis-1,10-phenanthroline has been prepared.     

Conjugated 1,10-Phenanthrolines as Tunable Fluorophores

Multiple emission colors can be generated with the same compound from a novel family of highly emissive and visibly fluorescent 1,10-phenanthrolines 1 . The emission wavelength of any derivative is dictated by the nature of its substituent and can be further modulated by exogenous additives such as protons or metal ions. R=H, Me, OMe, NMe₂.     

Facile synthesis of fluorine-containing 1,10-phenanthrolines by the pyridine-ring formation reaction of N-propargyl-5,7-bis(trifluoroacetyl)-8-quinolylamine with amines: isolation of the intermediates 1,4-dihydro-1,10-phenanthrolin-4-ols

Novel fluorine-containing 1,10-phenanthrolines having dialkyl-, alkyl, and arylaminomethyl substituents at the 3-position were easily synthesized in moderate yields by the pyridine-ring formation reaction of N-propargyl-5,7-bis(trifluoroacetyl)-8-quinolylamine with various amines. Unexpectedly, the reactive intermediates 1,4-dihydro-1,10-phenanthrolin-4-ols were isolated for the first time in the reactions with dialkylamines.     

Cobalt(II) complexes bearing 2-imino-1,10-phenanthroline ligands: synthesis, characterization and ethylene oligomerization

A series of cobalt(II) complexes containing 2-imino-1,10-phenanthrolines have been synthesized and characterized by elemental and spectroscopic analysis. The molecular structures of complexes 2, 3, 8 and 14 were confirmed by X-ray diffraction analysis. On treatment with methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), these cobalt(II) complexes show moderate to high catalytic activities for ethylene oligomerization and butene predominates among the oligomers produced. The parameters of the reaction conditions and the effects of the ligands environment were investigated. To cite this article: S. Jie et al. C. R. Chimie 9 (2006).     

Hydrothermal synthesis and structural characterization of three lanthanide coordination polymers with adipic acid and 1,10-phenanthroline

Three new lanthanide coordination polymers, [Ln(Ad)_3/2(Phen)] _n ·2nH₂O (Ln = Eu, 1; Pr, 2; Ad = adipate; Phen = 1,10-phenanthroline) and [Yb(Ad)_3/2(Phen)] _n ·nH₂O 3, were prepared by hydrothermal reactions. The structures of 1, 2 and 3 are reported. In compound 1, Eu(III) ions are bridged by adipate ligands in two modes into 2-D polymeric layers. Adjacent layers are assembled by hydrogen bonding and π–π stacking between 1,10-phenanthrolines into a 3-D supramolecular structure. Compound 2 is isostructural with 1. In compound 3, the Yb(III) ions are connected by adipate ligands in three modes into a 3-D network.