Alkyl-substituted 1,10-phenanthrolines

The scope of the Friedlander condensation in the preparation of chiral alkyl-substituted 1,10-phenanthrolines was investigated. A range of chiral [x, y-fc]-cycloalkeno-condensed phenanthrolines 343 and 344 were prepared in one step from the chiral pool of steroidal 342 or other cyclic ketones and 302 via base-catalyzed conditions (Scheme 73) (00MI423, 01JOC400). In the case of the major product, aldol bond formation takes place from the sterically less hindered a-carbon (C2) 343 while the steri-cally more hindered a-carbon (C6) 344 reacts to form the minor product (Scheme 73). 

An impressive example of the selectivity control brought about by even subtle changes in the chain length of alkyl-substituted phenanthrolines used as the colloid stabilizers was recently reported by Schmid for the semihydrogenation of hex-2-yne to cA-hex-2-ene. A mixture of seven- and eight-shell palladium clusters on Ti02,... 

For a particular iron(III) oxidant, the rate constant (log kpe) for electron transfer is strongly correlated with the ionization potential Ip of the various alkylmetal donors in Figure 4 (left) (6). The same correlation extends to the oxidation of alkyl radicals, as shown in Figure 4 (right) (2). [The cause of the bend (curvature) in the correlation is described in a subsequent section.] Similarly, for a particular alkylmetal donor, the rate constant (log kpe) for electron transfer in eq 1 varies linearly with the standard reduction potentials E° of the series of iron(III) complexes FeL33+, with L = substituted phenanthroline ligands (6). 

Phenanthroline and some of its alkyl-substituted derivatives improve the heat stability of polyesters594 and magnetic recording tape.595 They also improve the color of cured polyester resins.596 They are also useful in various electroplating and electrolytic processes597-601... 

While the effect on oxidation-reduction potentials of substituents on phenanthroline ligands is regular, studies of the oxidation of [Os(bipy)(terpy)X] + species, where X is an alkyl-substituted pyridine molecule (111), do not show a linear dependence of E° on the pA of X. These results have been explained in terms of the Baker-Nathan effect. However, taken in conjunction with the entropy data of Kratochvil and Knoeck (439) for substituted iron complexes, an explanation involving changes in solvation with substituents seems preferable. The potentials of various Os(II)/Os(III) couples (111) and Ru(II)/Ru(III) couples (220) have been used to study the effect of the overall charge on the... 

Unequivocal evidence for the formation of o -adducts has been obtained by X-ray diffraction analysis of those adducts which are stable enough to obtain their single crystals [11]. Indeed, the X-ray crystallography data are available for the anionic trinitrobenzene-methoxide and the Janovsky trinitrobenzene-acetone complexes [11, 201, 202] and for the o -adducts of isoquinoline [203], phthalazine [160], and 4,7-phenanthroline [161, 162] with dialkyl phosphonates. Also the X-ray data have been obtained for the neutral o -adducts resulting from the reactions of iV-methylacridinium ion with N-nucleophiles [204, 205] and for the o -adducts of iV-alkyl-substituted 2,3-dicyanopyrazinium and quinoxalinium salts with 0-, C-and P-nucleophiles [163, 194]. 

Classic A/-heterocychc ligands, eg, bipyridyl (bipy), terpyridyl, imidazole, pyrazine, phenanthroline, piperazine (including alkyl- and aryl-substituted derivatives), and polypyrazol-l-yl-borates (bis, tris, and tetra), have all been found to coordinate Th(IV) chlorides, perchlorates, and nitrates. The tripodal hydrotris(pyrazolyl)borates, HBPz, have been used to stabilize organometaHic complexes (31). Bis-porphyrin Th(IV) "sandwich" complexes have been... 

Abbreviations acac, acetylacetonate Aik, alkyl AN, acetonitrile bpy, 2,2 -bipyridine Bu, butyl cod, 1,5- or 1,4-cyclooctadiene coe, cyclooctene cot, cyclooctatetraene Cp, cyclopentadienyl Cp, pentamethylcyclopenladienyl Cy, cyclohexyl dme, 1,2-dimethoxyethane dpe, bis(diphenyl-phosphino)ethane dppen, cis-l,2-bis(di[Atenylphosphino)ethylene dppm, bis(diphenylphosphino) methane dppp, l,3-bis(diphenylphosphino)propane eda,ethylenediamine Et,ethyl Hal,halide Hpz, pyrazole HPz, variously substituted pyrazoles Hpz, 3,5-dimethylpyrazole Me, methyl Mes, mesityl nbd, notboma-2,5-diene OBor, (lS)-endo-(-)-bomoxy Ph, phenyl phen, LlO-phenanthroline Pr, f opyl py, pyridine pz, pyrazolate Pz, variously substituted pyrazolates pz, 3,5-dimethylpyrazolate solv, solvent tfb, tetrafluorobenzo(5,6]bicyclo(2.2.2]octa-2,5,7-triene (tetrafluorobenzobanelene) THE, tetrahydrofuran tht, tetrahydrothicphene Tol, tolyl. 

Di(p-tolyl)-1,10-phenanthroline 14 is synthesized in 70% yield from 1,10-phenanthroline 3 (1 equiv) and 4-lithiotoluene 13 (5 equiv), after hydrolysis, oxidation with Mn02 and recrystallization (Scheme 9.11). This reaction, detailed in Protocol 9, follows a literature procedure to make various poly-imines substituted by alkyl or aryl groups a to the nitrogen atoms.20... 

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