5-Amino-1,10-phenanthroline, reaction with

The amino acid derived chiral oxazolidinone 188 is a very commonly used auxiliary in Diels-Alder and aldol reactions. However, its use in diastereoselective 1,3-dipolar cycloadditions is less widespread. It has, however, been used with nitrile oxides, nitrones, and azomethine ylides. In reactions of 188 (R = Bn, R =Me, R = Me) with nitrile oxides, up to 92% de have been obtained when the reaction was performed in the presence of 1 equiv of MgBr2 (303). In the absence of a metal salt, much lower selectivities were obtained. The same observation was made for reactions of 188 (R = Bn, R = H, R = Me) with cyclic nitrones in an early study by Murahashi et al. (277). In the presence of Znl2, endo/exo selectivity of 89 11 and up to 92% de was observed, whereas in the absence of additives, low selectivities resulted. In more recent studies, it has been shown for 188 (R =/-Pr, R = H, R =Me) that, in the presence of catalytic amounts of Mgl2-phenanthroline (10%) (16) or Yb(OTf)3(20%) (304), the reaction with acyclic nitrones proceeded with high yields and stereoselectivity. Once again, the presence of the metal salt was crucial for the reaction no reaction was observed in their absence. Various derivatives of 188 were used in reactions with an unsubstituted azomethine ylide (305). This reaction proceeded in the absence of metal salts with up to 60% de. The presence of metal salts led to decomposition of the azomethine ylide. 

The oxidation of 1,7-phenanthrolines containing a hydroxy, methoxy, or amino group in the 5- or 6-position to 1,7 phenanthroline-5,6-dione (51) by nitric acid has been patented.249 250 Its monosemicarbazone has also been patented.251 l,7-Phenanthroline-5,6-dione (51) gives the diepoxide (52) on reaction with diazomethane.226... 

Pseudotetrahedral complexes of Cu1, [Cu(bpy)2]BF4 and similar derivatives with substituted dipyridyl ligands all gave intact cations in their ES mass spectra [37,38]. In an extension of this chemistry, bipyridyl groups were introduced into amino acid residues and, after reaction with Cu1, the intact cations of the copper(I) complexes of these species were observed [37]. The analogous [Cu(phen)2]+ ion and others derived from substituted phenanthrolines have also been observed [39]. For both the [Cu(bpy)2]+ and [Cu(phen)2] + species, collisional activation led to loss of one ligand. 

Wintersberger2 isolated from bovine pancreatic carboxypeptidase a peptide containing a thiol group involved in the binding of zinc. He first removed the zinc by exposure to a chelating agent (1,10-phenanthroline) or by denaturation, and then labeled the reactive sulfhydryl group by reaction with DDPM and determined the amino acid sequence. 

Particles from the blue-green algae Anacy sti s nidulans Synechococcu s leopoliensis) can catalyze O2 evolution with ferricyanide as acceptor in the light and the dark oxidation >f L-arginine (and other basic amino acids). The two eactions are both inhibited by o-phenanthroline, but respond to certain trivalent, divalent and monovalent cations (like e. g. La +, Ca " " and K" ") in different ways. These metals stimulate the Hill reaction with ferricyanide as acceptor, but totally inhibit L-arginine oxidation. 

Abstract A new thiourea ligand, N-[l,10-phenanthroline]-N -[(benzo-15-crown-5)yl]thiourea has been synthesized from the reaction of 5-amino-1,10-phenanthro-line with 15-isothiocyanatobenzo[15-crown-5] and its Cu(I) complex has been prepared. The stmctures of the ligand and its complex have been characterized by elemental analysis, UV-vis, FTIR, H NMR (DMSO-dg), NMR (DMSO-dg) and MS spectra (LC-MS). 

Mixed donor ligands. The complex [FeL3]Cl3 (L = acetylhydrazine) contains the ligand in its bidentate form, bonded via the carbonyl and primary amino-groups.Pyridine-2-carboxaldehyde and l,l,l-tris(aminoethyl)ethane react with Fe" via a template reaction to form [Fejlpyljltame) ], in which three molecules of carboxaldehyde have condensed with one molecule of triamine to produce (pyljltame). MeC(CH2N=CH-oc-py)3 the complex cation is octahedral. The complexes [FeL ] (L = l,10-phenanthroline-2-carboxamide, n = 1 or 2) have been isolated they are both six-co-ordinate. Very weak d-d bands have been identified in the spectra of complexes of ot-picolinic acid and quinaldic acid with Fe". ... 

Further examples of the Knorr reaction for the synthesis of 3-hydroxy-4,7-phenanthrolines are reported. A modification of the original synthesis239 of 3-hydroxy-1-methyl-4,7-phenanthroline involves isolation of the intermediate acetoacetanilide followed by ring closure with sulfuric acid.232 10-Amino-3-hydroxy-l-methyl-4,7-phenanthroline was obtained similarly from 4-amino-6-acetoacetamidoquinoline. Several 2-substituted l,3-dihydroxy-4,7-phenanthrolines were obtained likewise from diethyl alkylmalonates.101... 

A recent development31 is the preparation of metal polymer complexes directly on the electrode via the electrochemically induced polymerization of the metal complex. Ruthenium(II) and osmium(II) complexes with ligands containing aromatic amines, e.g. 3- or 4-aminopyridine or 5-amino-1,10-phenanthroline, are electrochemically polymerized to yield a film of the metal polymer on the electrode surface. The polymerization involves free radicals, which are formed via the initial oxidation of the metal complex to a radical cation and subsequent reaction of the radical cation with a base to yield the free radical. 

Reaction of the mono-protected proflavine 384 with 5-amino-[l,10]phenanthroline in the presence of paraformaldehyde in TFA produced a mixture mainly formed by the symmetrical phenanthroline 385 and the acridine-phenanthroline 386 while the acridine 387 was obtained, as traces (Scheme 78) <2002EJM315>. 

Treatment of (1) with oleum and nitric acids gives 5-nitro-[l] (6) with yields from 70 to 90%, depending on reaction temperature.5 A side product of this reaction is the [l]-5,6-dione (7), whose colorless iron(II) complex was of little interest at the time of its discovery. A versatile precursor to many other phenanthrolines, (7) is readily prepared by treatment of (1) with sulfuric and nitric acids in the presence of bromide.38-40 Through a dioxime intermediate, 5,6-diamino-[l] (8) is obtained.41 5-Amino-[l] (9) may be prepared directly from (6) with Sn-HCl reduction.39 Alternatively, amino-[l] may be formed by conversion of the corresponding chloro-[l] with ammonia.42... 

The cofactors linked to the amino-acid residues on the L- and M-subunits might be labeled with subscripts L and M. However, this designation becomes a little complicated when it comes to the quinones, as the quinone that is huried in a pocket formed from amino-acid residues ofthe M-subunit is actually located in a region dominated by a branch of the L-subunit. We will therefore adopt a nomenclature which uses the subscript A for an L-dominated branch and B for an M-dominated branch, i.e., Ba and Bq for BChls b, BOa and BOg for BOs b, and Qa and Qb for the two quinones. Thus Qa, menaquinone-9, although hound to the M-subunit is located at the end of an L-branch, while Qb, ubiquinone-9, is bound to the L-suhunit but located near the end of an M-branch. It is to be noted that -70% of the Qs-binding sites in the Rp. viridis crystals appear as empty cavities on the electron-density map, as most of the Qb was lost during isolation ofthe Rp. viridis reaction center. This cavity, however, can be filled with some exogenous quinone or a molecule of the inhibitors o-phenanthroline or terbutryn. 

Several examples have been reported of the preparation of 4,7-phenanthrolines from substituted 6-aminoquinolines by the Skraup and related reactions. In this way, 5-methoxy-, 5-chloro-, 3-methyl-6-methoxy-, l-methyl-, and l,2,3,4-tetrahydro-4-methyl-4,7-phenanthrolines have been synthesized while improvements have been made to the synthesis of the 3-methyl derivative. The Skraup reaction has also been applied to quaternary salts of 6-aminoquinolines. For example, 5-chloro-4-methyl-4,7-phenanthrolinium iodide (36) was obtained from the methiodide of 6-acetamido-8-chloroquinoline (35). Cyclizations starting from aminocarbostyrils have also been reported. Thus, 6-amino-1-methylcarbostyril (37) was condensed with paraldehyde in the presence of concentrated hydrochloric acid to afford 3,4-dihydro-4,8-dimethyl-3-oxo-4,7-phenanthroline (38), while under Skraup conditions, with glycerol as condensing agent, 6-amino-4-methylcarbostyril afforded 3,4-dihydro- l-methyl-3-oxo-4,7-phen-... 

The very sharp crystalline formation of the C. acidi-urici ferredoxin relative to that from C. pasteurianum has been correlated with their different amino acid compositions, in particular with the extra proline at site 16 (294). It is hence interesting that the kinetics of heat-inactivation at 70 °C indicates a higher stability for the former. Similarly, the aerobic reaction of the C. acidi-urici and C. tartarivorum ferredoxins with o-phenanthroline is faster for the most thermolabile of the two. This was reflected clearly in the temperature dependence of the reaction (285). Along these lines, Gillard et al. (295) have reported that iron is removed from native Peptostreptococcus elsdenii and from C. pasteurianum ferredoxins by o-phenanthroline while this ferrous chelator was found inactive on the C. acidi-urici protein. The magnitude of these differences needs further substantiation since other authors have claimed that o-phenanthroline can sequester iron from the C. acidi-urici protein as well (296). 

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