Remarkable reactions of cyclooctatetraene diiron-bridging carbyne complexes with amino and amido compounds: nucleophilic addition to and breaking of the cyclooctatetraene ring

The reactions of the cationic, diiron-bridging carbyne complexes [Fe(2)(mu-CAr)(CO)(4)(eta(8)-C(8)H(8))]BF(4) (1, Ar=C(6)H(5); 2, Ar=p-CH(3)C(6)H(4); 3, Ar=p-CF(3)C(6)H(4)) with LiN(C(6)H(5))(2) in THF at low temperature gave novel N-nucleophilic-addition products, namely, the neutral, diiron-bridging carbyne complexes [Fe(2)(mu-CAr)(CO)(4)(eta(7)-C(8)H(8)N(C(6)H(5))(2))] (4, Ar=C(6)H(5); 5, Ar=p-CH(3)C(6)H(4); 6, Ar=p-CF(3)C(6)H(4))). Cationic bridging carbyne complexes 1-3 react with (C(2)H(5))(2)NH, (iC(3)H(7))(2)NH, and (C(6)H(11))(2)NH under the same conditions with ring cleavage of the COT ligand to produce the novel diiron-bridging carbene inner salts [Fe(2)[mu-C(Ar)C(8)H(8)NR(2)](CO)(4)] (7, Ar=C(6)H(5), R=C(2)H(5); 8, Ar=p-CH(3)C(6)H(4), R=C(2)H(5); 9, Ar=p-CF(3)C(6)H(4), R=C(2)H(5); 10, Ar=C(6)H(5), R=iC(3)H(7); 11, Ar=p-CH(3)C(6)H(4), R=iC(3)H(7); 12, Ar=p-CF(3)C(6)H(4), R=iC(3)H(7); 13, Ar=C(6)H(5), R=C(6)H(11); 14, Ar=p-CH(3)C(6)H(4), R=C(6)H(11), 15, Ar=p-CF(3)C(6)H(4), R=C(6)H(11)). Piperidine reacts similarly with cationic carbyne complex 3 to afford the corresponding bridging carbene inner salt [Fe(2)[mu-C(Ar)C(8)H(8)N(CH(2))(5)](CO)(4)] (16). Compound 9 was transformed into a new diiron-bridging carbene inner salt 17, the trans isomer of 9, by heating in benzene. Unexpectedly, the reaction of C(6)H(5)NH(2) with 2 gave a novel COT iron-carbene complex [Fe(2)[=C(C(6)H(4)CH(3)-p)NHC(6)H(5)](mu-CO)(CO)(3)(eta(8)-C(8)H(8))] (18). However, the analogous reactions of 2-naphthylamine with 2 and of p-CF(3)C(6)H(4)NH(2) with 3 produce novel chelated iron-carbene complexes [Fe(2)[=C(C(6)H(4)CH(3)-p)NC(10)H(7)](CO)(4)(eta(2):eta(3):eta(2)-C(8)H(9))] (19) and [Fe(2)[=C(C(6)H(4)CF(3)-p)NC(6)H(4)CF(3)-p](CO)(4)(eta(2):eta(3):eta(2)-C(8)H(9))] (20), respectively. Compound 18 can also be transformed into the analogous chelated iron-carbene complex [Fe(2)[=C(C(6)H(4)CH(3)-p)NC(6)H(5)](CO)(4)(eta(2):eta(3):eta(2)-C(8)H(9))] (21). The structures of complexes 6, 9, 15, 17, 18, and 21 have been established by X-ray diffraction studies.     

Features of the mass spectrometric behavior of porphyrin systems with a voluminous substituent in the meso position

Summary Features of the mass-spectrometric behavior of the tetramethyl ester of -meso-(3-acetyl-2,4-dimethyl-5-pyrryl)coproporphyrin II and the dimethyl ester of -meso-(3-acetyl-2,4-dimethyl-5-pyrryl) mesoporphyrin III, each of which contains a voluminous pyrryl radical with a conjugated ring system in the meso position, have been investigated.M. M. Shemyakin Institute of the Chemistry of Natural Compounds, Academy of Sciences of the USSR. M. V. Lomonosov Moscow Institute of Fine Chemical Technology. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 197–199, March. 1971.     

Catalytic enantioselective Michael addition of 1,3-dicarbonyl compounds to nitroalkenes catalyzed by well-defined chiral ru amido complexes

Well-defined chiral Ru amido complexes promoted asymmetric Michael addition of 1,3-dicarbonyl compounds including malonates, beta-keto esters, and 1,3-diketones to nitroalkenes to give the corresponding adducts with excellent ees and in excellent yields.     

Anomalous NMR behavior of meso compounds with remote stereogenic centers on addition of chiral shift reagent or chiral solvating agent

A problem has arisen in using chiral shift reagents (CSR) and chiral solvating agents (CSA) to determine meso and racemic forms of diastereoisomers in which the stereogenic centers of the molecules are separated by achiral spacers. It is found that NMR signals of both meso and racemic forms of diastereoisomers may exhibit doubling on addition of CSR/CSA, which means that unequivocal assignments cannot be made without characterizing the effects for separate meso and racemic forms; this is particularly important for additions of CSR/CSA at relatively low concentrations, which always result in the splitting of some NMR signals of diastereoisomers. The phenomenon is demonstrated in the (31)P NMR spectra of meso and racemic forms of three spermine-bridged gem-disubstituted cyclotriphosphazatrienes, 1a-c, and compared with analogous achiral molecules, the per-substituted spermine-bridged cyclotriphosphazatrienes 2a-d. As expected, only one set of (31)P NMR signals was observed for the achiral compounds 2a-d, even on addition of CSA. Two sets of (31)P NMR ABX multiplets corresponding to meso and racemic diastereoisomers were observed for compounds 1a-c; on addition of CSA, the signals of at least one of the multiplets for each compound separated into more than the expected groups of three lines with an intensity distribution of 2:1:1. To understand this phenomenon, the meso and racemic forms of 1a and 1b and the meso form of 1c have been separated and characterized by X-ray crystallography. On addition of CSA to the racemic forms of 1a and 1b, the (31)P NMR spectrum shows the expected doubling of signals, but, unexpectedly, the same is observed for each of the meso forms of 1a-c. Analogous results using both CSA and CSR have been obtained for the meso and racemic forms of the diastereoisomeric piperazine-bridged macrocyclic-phosphazene compound, 3, whereas no effect was observed for the two meso forms of the doubly bridged macrocyclic-phosphazene compound 4. The phenomenon of doubling of the (31)P NMR signals of the meso form of singly bridged cyclotriphosphazatrienes, 1a-c and 3, is explained by consideration of the equilibrium in solution of independent complexation of a chiral ligand with molecules that have two chiral cyclophosphazene moieties separated by an achiral spacer group. The results show that the stereogenicity of such diastereoisomeric molecules in solution cannot be characterized unequivocally by NMR measurements on addition of either CSR or CSA.     

Improvement of a biomimetic porphyrin catalytic system by addition of acids

The conditions of the use of the manganese/porphyrin/imidazole system needed to be improved in order to obtain larger amounts of models of metabolites. An increase of the oxidation yields and a better preservation of this catalytic system have been obtained on the examples of various alkanes, by an acid addition in the reaction mixture. Three manganoporphyrins were checked for evaluation of the reaction. These results were extended to molecules of therapeutical interest such as ibuprofen and phenylbutazone.     

Chiral recognition of amino acids and dipeptides by a water-soluble zinc porphyrin

A chiral water-soluble zinc porphyrin was optically resolved on a chiral HPLC column, and the binding of chiral amino acids and peptides to each of the enantiomers was examined spectrophotometrically in basic aqueous solution. The binding data apparently indicated that the zinc porphyrin has chiral selectivity for amino acids and dipeptides. This was reasonably explained in terms of the triple cooperation of coordination, Coulomb, and steric interactions of the chiral amino carboxylates with the porphyrin. A compensatory relationship among the thermodynamic parameters for chiral recognition was also shown.     

Hydroalumination of diazo and azido compounds: An Al-H addition to end-on nitrogen of substrates

This paper reports the reactions of a monomeric aluminum dihydride LAlH₂ (L = HC[C(Me)N(Ar)]₂, Ar = 2,6-i-Pr₂C₆H₃) with diazo, azido, and terminal alkyne compounds. The reaction of LAlH₂ with N₂CH(SiMe₃) and N₃(1-Ad) occurred through an Al-H addition to end-on nitrogen to yield respective compounds LAl[N(H)N = CH(SiMe₃)]₂ (1) and LAl[N(H)N=N(1-Ad)]₂ (2), while the reaction of LAlH₂ with PhC≡CH occurred through a stepwise deprotonation to yield LAlH(C≡CPh) (5) and LAl-(C≡CPh)₂ (6), respectively. 2 further reacted by N₂-release to yield LAl[NH(1-Ad)][N(H)N=N(1-Ad)] (3) and LAl[NH-(1-Ad)]₂ (4) upon the increased temperature treatment. Compounds 1–6 have been fully characterized, revealing novel reactivity patterns of LAlH₂ toward different substrates under the steric influence from the bulky L ligand at Al.     

Gelation of an amino acid ionic liquid by the addition of a phosphonium-type zwitterion

1-Ethyl-3-methylimidazolium leucine, a typical amino acid ionic liquid, turns into a thermotropic and ion conductive gel while retaining its ion pair upon adding a phosphonium-type zwitterion.     

Sandwich structure of a ruthenium porphyrin and an amino acid hydrazide for probing molecular chirality by circular dichroism

Owing to the strong Lewis acidity of ruthenium porphyrins, a commercial carbonyl ruthenium porphyrin and an amino acid hydrazide can assemble into a sandwich structure. The nature of such a structure is diagnostic of the absolute configuration of the amino acid by circular dichroism.     

Carbocyanine dyes with an o-hydroxyaryl substituent in the meso position of the polymethine chain

Carbocyanine dyes with an o-hydroxyaryl substituent in the meso position of the polymethine chain were obtained from o-hydroxybenzoyl derivatives of the Fischer base and heterocyclic methylene bases (1,3,3-trimethyl-2-methyleneindoline, 1-ethyl-4-methylene-1,4-dihydroquinoline, and 1-methyl-2-methylene-1,2-dihydroquinoline) in the presence of phosphorus oxychloride. The symmetrical indolenine dyes exist in the colorless spiropyran form in an alkaline medium. The unsymmetrical carbocyanines with a quinoline fragment do not form a spiro form and are deeply colored compounds; this is explained by their open dipolar structure.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 100–103, January, 1988.     

Determination of nitrogen content of methylamine and dimethylamine compounds by an automatic rapid nitrogen analyser

Summary It has been observed that when the Heraeus automatic nitrogen analyser is used for compounds containing anN-methyl group, values higher than theoretical are obtained, because the volume of methane arising from the methyl group is measured along with the nitrogen. This interference is found to be eliminated by increasing the temperature of the oven. When the traditional Pregl-Dumas method is used, the duration of combustion can be lengthened to eliminate this effect.

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Zusammenfassung Bei Verwendung des automatischen Gerätes von Heraeus zur N-Bestimmung in N-Methylverbindungen werden überhöhte Werte erhalten, da sich Methan bildet, das mit Stickstoff gemeinsam gemessen wird. Diese Störung läßt sich durch Erhöhung der Ofentemperatur bescitigen. Wenn die herkömmliche Methode von Dumas-Pregl verwendet wird, kann man den gleichen Erfolg durch Verlängerung der Verbrennungszeit erzielen.

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Work performed under the auspices of the U. S. Department of Energy under contract No. W-7405-Eng-48.     

Enantioselective palladium-catalyzed addition of 1,3-dicarbonyl compounds to an allene derivative

Enhancing atom economy of the metal‐catalyzed asymmetric allylic alkylation (AAA) shifts from the usual nucleophilic displacement of a leaving group to an addition of a pronucleophile to a double bond. Using 1‐alkoxyallenes as proelectrophiles, the palladium‐catalyzed AAA proceeds with 1,3‐dicarbonyl compounds as pronucleophiles with excellent regioselectivity and enantiomeric excess under optimized conditions. The pH of the medium proved crucial for reactivity/selectivity. By using the more acidic Meldrum's acids, the reactions required a co‐catalytic amount of Brønsted acid, such as trifluoroacetic acid. Single regioisomeric products of 82–99 % ee were obtained. On the other hand, the less acidic 1,3‐diketones failed to react under such conditions. The fact that a less acidic acid like benzoic acid sufficed, suggested the need for general base catalysis as well. Thus, a mixture of triethylamine and benzoic acid proved optimal (ee's 93–99). Employment of the (R,R)‐phenyl Trost ligand gave a product with S configuration. A model to rationalize the results has been developed.     

Imido,amino and amido coordination of diaminouracil to rhenium(V)

Reaction of equimolar quantities of cis-[ReO₂I(PPh₃)₂] with 5,6-diamino-1,3-dimethyl-2,4-dioxopyrimidine (H₂ddd) in acetonitrile led to the formation of [Re(ddd)(Hddd)I(PPh₃)₂] (ReO₄) (1). A single-crystal X-ray crystal structure shows that ddd is coordinated as a monodentate through the doubly deprotonated amino nitrogen and is therefore present as an imide. The chelate Hddd is coordinated as a bidentate via a neutral amino nitrogen atom, trans to the imido nitrogen, and a singly deprotonated amido nitrogen atom, trans to the iodide.     

Ruthenium-catalyzed addition of carboxylic acids or cyclic 1,3-dicarbonyl compounds to propargyl alcohols

Monomeric ruthenium(0) complexes containing redox-coupled dienone ligands were found to catalyze the regio-selective addition of carboxylic acids or cyclic 1,3-dicarbonyl compounds to propargyl alcohols.     

Dearomatization of oxa- or selenadiazolopyridines with neutral nucleophiles as an efficient approach to pharmacologically relevant nitrogen compounds

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Binuclear organometallic compounds VIII. Oxidative addition of Si-H or Si-Cl compounds to low valent Fe, Co, or Ni complexes stabilised by mono- or bi-dentate phosphines

The reactions of [(Ph₃P)₄Ni], [(Ph₃P)₃CoN₂], [(dp)₂Ni], [(dp)₂CoH], [(dp)₂Fe(C₂H₄)] or [(dp)₂FeH₂] (dp = Ph₂PCH₂CH₂Ph₂P) with Ph_nSiCl_4-n (n = 1, 2, or 3), Ph_nSiH_4-n, X₃SiH (X = Cl or Et), or R₂ClSiH (R = Ph or Me) have been investigated. Solid complexes were isolated which, for the most part, were insoluble in non-polar solvents. Assignments of structures are therefore incomplete, and are based on microanalysis, IR spectra, analogies with established reactions, and (in some cases) chemical degradation. Evidence is presented for the following: (i) for Ni^II, products from [(Ph₃P)₄Ni] and HSiXX′X″ (XX′X″ = Ph₃, Ph₂H or PhH₂), the cyclic [(Ph₃P)₂NiSiCl₂]₂, and the five-coordinate [(dp)₂-NiX]⁺[SiCl₃]^- (X = H or Cl₃Si); (ii) for Co^III, the six-coordinate cis-octahedral [(dp)₂CoH₂]⁺ [SiXX′X″]^- (XX′X″ = Cl₃, Cl₂Me, ClMe₂, or ClPh₂); and for Fe^II, the four-coordinate [(dp)FeH(SiCl₃)] and the six-coordinate [(dp)₂Fe(X)SiCl₃] (X = H, Cl, or Cl₃Si).     

钌(Ⅱ)卟啉催化含氮芳杂环的酰亚胺化

目前,N-N键形成的方法尽管有:催化胺化[1],利用叠氮化合物[2,3],氯氨-T法[4],亚硝化-还原,羟胺氧磺酸等方法。这些方法都各有千秋,互相补充。但我们为合成目标化合物在尝试这些方法时,仅过渡金属配合物Ru(TTP)(CO)催化胺化法得到较为理想结果。加之近年来卟啉配合物催化形成C-N键已成为获得某些天然产物和生物活性分子的具有吸引力的方法之一[5-13]。我们希望利用Ru(TTP)(CO)催化的氮宾插入反应在含sp2N的杂环N上直接引入磺酰亚胺,为我们进一步获得新的生物活性化合物以及进行体外筛选提供可能。也为合成一些具有生物活性化合物开辟…