Stickstoffhaltige Dieisen-hexacarbonyl-Komplexe aus 3-Phenyl-2H-azirinen

Nitrogen-containing diiron-hexacarbonyl complexes from 3-phenyl-2H-azirines Reaction of 2,2-dimethyl-3-phenyl-2H-azirine ( 1 ) with diiron-enneacarbonyl yields as an insertion product, and in addition to other products, the diiron-hexacarbonyl complex 2 (Scheme 1), whose structure was derived from spectral data, in particular ¹³C-NMR.-data (Table 1). With trimethylamine oxide in benzene, 2 is converted into the urea derivative 3 , and yields with cerium (IV) ammonium nitrate the nitrate 4 (Scheme 1). The analogous complexes 6 and 9 have been obtained by irradiation of 1-phenyl-vinyl azide ( 5 ) and ironpentacarbonyl (Scheme 1) and from vinyl isocyanate ( 8 ) and diiron-enneacarbonyl at 40° (Scheme 2), respectively. The azirine 1 , an acetylenic compound and diiron-enneacarbonyl in benzene react to give complexes of type 10 as the main product (Scheme 3). The structure of complex 10 has been established by X-ray single crystals analysis. On the ¹³C-NMR. time scale the carbonyl groups of compound 10 show a fluxional behaviour: below ?50° the CO-groups of one of the two Fe(CO)₃-groups undergo intranuclear exchange, above ?50° the CO-groups of both Fe(CO)₃-groups undergo intranuclear exchange. Tentative reaction mechanisms for the formation of the complexes of type 2 and 10 are formulated in Schemes 5, 6 and 7.     

Synthesis of 3-alkyl-6-phenyl-4(3H)-pteridinones and their 8-oxides. Potential substrates of xanthine oxidase

Synthetic routes for the preparation of 3-alkyl-6-phenyl-4(3H)-pteridinones 6 and their corresponding 8-oxides 5 (R = CH₃, C₂H₅, (CH₂)₂CH₃, (CH₂)₃CH₃, CH(CH₃)C₂H₅, CH(CH₃)₂ and CH(C₂H₅)CH₂OCH(OC₂H₅)₂ are described and their reactivities towards xanthine oxidase from Arthrobacter M-4 are determined. Only the 3-methyl derivative of 6-phenyl-4(3H)-pteridinone and its 8-oxide i. e. 6a and 5a are found to be substrates although their reactivities are still very low. Oxidation takes place at C-2 of the pteridinone nucleus. All the 3-alkyl derivatives are less tightly bound to the enzyme than 6-phenyl-4(3H)-pteridinone. Introduction of the N-oxide at N-8 considerably lowers the binding of the substrates. Inhibition studies have revealed that 3-methyl-6-phenyl-4(3H)-pteridinone ( 6a ) is a non-competitive inhibitor with a Ki-value of 47 μM and the 3-ethyl derivative ( 6b ) an uncompetitive one with a Ki-value of 19.6 μM.     

Organometallic chemistry of the transition metals: XXXIII. Some new reactions of cyclopentadienyltetracarbonylniobium

Photolysis of C₅H₅Nb(CO)₄ with excess cycloheptatriene gives the dark brown tetrahapto complex C₅H₅Nb(CO)₂C₇H₈ but no C₅H₅NbC₇H₇ analogous to the corresponding reaction of C₅H₅V(CO)₄ with cycloheptatriene. Photolysis of C₅H₅Nb(CO)₄ with cyclooctatetraene gives the dark green tetrahapto complex C₅H₅Nb(CO)₂C₈H₈, the C₈H₈ ring in this complex remains fluxional below -86° C. Reaction of C₅H₅Nb(CO)₄ with I₂ gives re-brown C₅H₅Nb(CO)₃I₂ in which the carbonyl groups are relatively labile. Thus reaction of C₅H₅Nb-(CO)₃I₂ with (CH₃)₂PCH₂CH₂P(CH₃)₂ under ambient conditions results in the rapid replacement of two CO groups to give C₅H₅Nb(CO)[(CH₃)₂PCH₂CH₂ -P(CH₃)₂]I₂. Treatment of C₅H₅V(CO)₄ with I₂ at room temperature gives the carbonyl-free complex C₅H₅VI₂ with no evidence for any cyclopentadienyl-vanadium carbonyl iodide intermediates.     

Reactions of 1, 5-diketones. XX. Semicyclic 1, 5-diketones in the fischer reaction

Monophenylhydrazones involving both the phenacyl carbonyl group and the ring carbonyl group are formed as intermediates in the reaction of semicyclic 1, 5-diketones of the 2-(phenacylobenzyl) cyclohexanone type with phenylhydrazine in acid media. The former undergo subsequent conversion to the corresponding substituted indoles, whereas the latter are converted to substituted 1H-2, 3, 3a, 4-tetrahydropyrido [3, 2, l-j, k] carbazoles; in addition, the corresponding 5, 6, 7, 8-tetrahydroquinoline derivatives are also partially formed.See [1] for communication XIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 645–650, May, 1976.     

Synthesis of 4H-pyrazolo- and 4H-pyrrolophenothiazin-4-one derivatives

5-Methyl- and 6-methyl-2-phenyl-2H-indazole-4,7-diones were condensed with 2-aminobenzenethiol or 6-substituted-3-aminopyridine-2(1H)thiones 4 to produce a new type of 5-methyl-2-phenyl-4H-pyrazolophenothiazin-4-ones or 8-substituted-7-aza-5-methyl-2-phenyl-4H-pyrazolophenothiazin-4-one derivatives. From 6-bromo-2,5-dimethyl-1,3-diphenyl-2H-isoindole-4,7-dione and 4 8-substituted-7-aza-2,5-dimethyl-1,3-diphenyl-4H-pyrrolophenothiazin-4-one derivatives were also prepared.     

Photochemische Synthesen potentiell hypoglykämisch wirkender 3-Oxazoline

Photochemical Syntheses of 3-Oxazolines which Possibly Exhibit Hypoglycemic Activity Reactions of photochemically generated benzonitrile methylides 2 with carbonyl compounds 3 yielded 3-oxazolines of the types 5 and 6 (Scheme 1). Photooxidation of 5-[p-(dimethylamino)phenyl]-2,2-dimethyl-4-phenyl-3-oxazoline ( 5a ) gave 4′-(2,2-dimethyl-4-phenyl-3-oxazolin-5-yl)-N-methylformanilide ( 6r ) which could be transformed to 2,2-dimethyl-5-[p-(methylamino)phenyl]-4-phenyl-3-oxazoline ( 6s ) by photodecarbonylation. Thirty 3-oxazolines of types 5 and 6 have been synthesized and tested by oral and/or intraperitoneal administration to starved rats and obese-hyperglycemic mice.     

Alkylation selective de substituants aromatiques actives par un greffon chrome carbonyle

The complexes (C₆H₅X)Cr(CO)₃, where X is COCH₃, CH₂,CO₂CH₃ and CH₃ are readily alkylated by either sodium hydride in DMF or by potassium tert-butoxide in DMSO. The activating influence brought about by the electron-withdrawing effect of the Cr(CO)₃ group can be modified by replacement of a carbonyl group by P(OPh)₃ or CS which lead to mono or dialkylated products respectively.     

New polyfunctional silicon-containing amines C6[CH2CH2SiMe(OCH2CH2NR2)2]6 (R = H,Me) and their reactions with cobalt(ii) chloride and dicobalt octacarbonyl

Hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene and hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene C₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆ (4, R = H; 5, R = Me) were prepared from hexakis(methyldichlorosilylethyl)benzene C₆(Cl₂MeSiCH₂CH₂)₆ and 2-aminoethanol or N,N-dimethyl-2-aminoethanol, respectively. Compounds 4 and 5 react with anhydrous cobalt (ii) chloride to give poorly soluble dodecachloro{hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene}hexacobalt and dodecachloro{hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene}hexacobalt {Co₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}Cl₁₂ (R = H or Me), respectively. Polyfunctional amine 4 reacts with dicobalt octacarbonyl to produce hexakis[bis(2-aminoethoxy)methylsilylethyl]benzenedicobalt(ii) tetrakis(tetracarbonylcobaltate) {Co₂[(NH₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}[Co(CO)₄]₄. N,N-Dimethyl-substituted polyfunctional amine 5 is lowly reactive in the reaction with Co₂(CO)₈, whereas the simplest model of this compound, viz., bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane (NMe₂CH₂CH₂O)₂SiMe₂, slowly reacts with Co₂(CO)₈ to give tris[bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane]cobalt(ii) bis(tetracarbonylcobaltate) {Co[(NMe₂CH₂CH₂O)₂SiMe₂]₃}[Co(CO)₄]₂. Thermal decomposition and transformations of the resulting complexes under the action of oxygen and water were studied.     

Übergangsmetall-substituierte vb elementsysteme : VIII. Darstellung und komplexchemisches verhalten von cyclopentadienyl(tricarbonyl)viametall-dimethylstibinen

Starting with the cyclopentadienyl(carbonyl)metal anions [π-C₅H₅(CO)₃M]^? (M = Cr, Mo, W) and (CH₃)₂SbBr, transition metal-substituted stibines of the form π-C₅H₅(CO)₃MSb(CH₃)₂ are obtained. The nucleophilic character of the VB element primarily determines the reactivity of these species, and shows itself in alkyl halide quarternization (a) or ligand exchange on activated metal carbonyl complexes (b). (a) yields the trialkylstibine-substituted metal cations [π-C₅H₅-(CO)₃MSb(CH₃)₂R]X (R = CH₃, CH₂CH=CH₂, CH₂C₆H₅; X = Br, J), (b) leads to the formation of the metal carbonyl derivatives LM(CO)₅, L₂M(CO)₄ (M = Cr, Mo, W), LNi(CO)₃ and LFe(CO)₄ [L = (CH₃)₂SbM(CO)₃-π-C₅H₅] which are the first (CH₃)₂Sb-bridged polynuclear complexes. Phosphorus ylides cause heterolytic cleavage of the antimonytransition metal bond. Transfer of the (CH₃)₂Sb-group to the ylidic carbanion occurs via substitution/transylidation. All new compounds have been fully characterized by means of ¹H NMR, IR and mass spectroscopy     

Photochemische Cycloadditionen von 3-Phenyl-2H-azirinen mit aktivierten Doppelbindungen. Vorläufige Mitteilung

Irradiation of 2-methyl- ( 1a ), 2,2-dimethyl- ( 1b ) and 2,3-diphenyl-2H-azirine ( 1c ) in the presence of diethyl mesoxalate yields the corresponding 4-phenyl-5,5-diethoxycarbonyl-3- oxazolines 3a–c . Similar cycloadducts are observed (cf. 6 ) by irradiation of 1b and 1c in the presence of trifluoroacetophenone. When ethyl cyanoformate is used as trapping agent photolysis of 1b or 1c leads to cycloadducts with the carbonyl and nitrile group, respectively which are present in the cyanoformate.     

Enantioselective addition of diethylzinc to benzaldehyde in the presence of sulfur-containing pyridine ligands

Diastereomerically pure hydroxy and thiol derivatives of (5S,7S)-5,7-methane-6,6-dimethyl-2-phenyl-5,6,7,8-tetrahydroquinoline were prepared and assessed in the enantioselective addition of diethylzinc to benzaldehyde: enantioselectivities up to 62% were obtained.     

Crystal and molecular structure of 7,7-dimethyl-2,3-di(4-methoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinoline

An x-ray crystallographic investigation of 7,7-dimethyl-2,3-di(4-methoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinoline, obtained by the hydrolysis of its oxime, was undertaken. The oxime, together with the isomeric oxime of 7,7-dimethyl-2,4-di(4-methoxyphenyl)-5-oxo-5,6,7,8-tetrahydroquinoline, is formed in the reaction of 5,5-dimethyl-2-[1,3-di(4-methoxyphenyl)-3-oxopropyl]cyclohexane-1,3-dione with hydroxylamine hydrochloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1085–1088, August, 1987.     

Umsetzungen von Allyldichlorphosphit und Allyldifluorphosphit mit einigen Verbindungen von Übergangsmetallen; Darstellung und spektroskopische Untersuchung von Allyldichlor- bzw. Allyldifluorphosphit-Carbonyl-Metall(0)-Koordinationsverbindungen (MetallCr,Mo, W,Fe)

Reactions of Allyldichlorophosphite and Allyldifluorophosphite with some Transition Metal Compounds; Synthesis and Spectroscopic Identification of Allyldichloro- and Allyldifluorophosphite-Carbonyl-Metal(0) Coordination Compounds (Metal?Cr, Mo, W, Fe) In the reactions of allyldifluorophosphite ( 1 ) and allyldichlorophosphite ( 2 ) with the carbonyl compounds (C₇H₈)M(CO)₃ (M?Cr, Mo; C₇H₈ ? cycloheptatriene), W(CO)₅THF (THF = tetrahydrofuran), Fe(CO)₅ or Fe₂(CO)₉ the allyldichloro- and allyldifluorophosphite-carbonyl-metal compounds fac-(AllOPF₂)₃Cr(CO)₃ 3 a , mer-(AllOPF₂)₃Cr(CO)₃ 3 b , fac-(AllOPF₂)₃Mo(CO)₃ 4 , fac-(AllOPCl₂)₃Mo(CO)₃ 5 , (AllOPF₂)W(CO)₅ 6 , (AllOPCl₂)W(CO)₅ 7 , (AllOPF₂)Fe(CO)₄ 8 and (AllOPCl₂)Fe(CO)₄ 9 were formed (All = CH₂?CHCH₂). In 8 and 9 the ligands 1 or 2 are axially orientated. The validity of the concept of hard and soft acids and bases (HSAB-concept) and of the 18-valency electron rule (18-VE-rule) was confirmed. The allyl dihalophosphites 1 and 2 coordinate via phosphorus. The allylic π-system was not involved in the coordinative bond. The characterization of the coordination compounds 3 , 4 , 5 a , 5 b und 6 ? 9 was based on their IR and NMR spectra, and on the mass spectra.     

Synthesis and structural characterization of acetatobis(triphenylphosphine)dicarbonylmanganese(I), (CH3CO2)Mn(CO)2[P(C6H5)3]2: An organometallic complex containing a chelating acetate ligand

The accidental but intriguing synthesis of acetatobis(triphenylphosphine)dicarbonylmanganese(I), (CH₃CO₂)Mn(CO)₂[P(C₆H₅)₃]₂, has been accomplished by the reaction of NaMn(CO)₅ with (CH₃)₃SiCl followed by the addition of triphenylphosphine and acetic acid. A three-dimensional single-crystal X-ray diffraction analysis has shown an octahedral-like molecule containing a symmetrically oxygen-chelating acetate group, the first such group to be reported in a metal carbonyl complex. The two triphenylphosphine ligands occupy mutually trans positions with the two carbonyl ligands possessing the remaining cis sites in the octahedral complex. The compound crystallizes with four molecules in a monoclinic unit cell of space group symmetry $\text{P}\text{2}{}_1\text{c}$ and of dimensions a = 17.744(2) Å, b = 9.692(1) Å, c = 20.004(2) Å, and β = 106.195(4)°. The relatively long MnO(acetate) bond lengths [2.066(6) and 2.069(7) Å] and the relatively short MnCO bond lengths [1.701(12) and 1.760(13) Å] and the relatively short MnP(C₆H₅)₃ bond lengths [2.260(3) and 2.275(3) Å], compared to the corresponding MnCO and MnP(C₆H₅)₃ bond lengths in other manganese carbonyl triphenylphosphine complexes, are rationalized on the basis that the acetate ligand in this molecule functions primarily as a σ-donor.     

Reactions of Tricyclic Vinylcyclopropanes with Metal Carbonyls

Irradiation of the tricyclic vinylcyclopropane 3 and Fe(CO)₅ resulted in the formation of the s?,π-bonded iron complex 7 and the π,π-bonded iron complex 8 (Scheme 2). Complex 8 was easily degraded with silica gel to give hydrocarbon 9 , which reproduced 8 by photolysis in the presence of Fe(CO)₅. Photolysis of 7 afforded a mixture of 3 (23%), 9 (27,5%), and three other hydrocarbons. Oxidative degradation of 7 with ceric ammonium nitrate in methanol gave the dimethoxy-hydrocarbon 10 . - The tricyclic hydrocarbon 3 isomerized thermally to the bicyclic hydrocarbon 11 (with CH₃? C(9) in an exo position) via a homosigmatropic [1,5]-H-shift. On the other hand, 3 was converted into the other isomer 14 (with CH₃? C(9) in an endo position) by action of Mo(CO)₆ or TsOH. Both isomers 11 and 14 reacted with 4-phenyl-1,2,4-triazoline-3,5-dione to give the isomeric Diels-Alder adducts 12 and 15 , respectively, which were photochemically converted into the cage compounds 13 and 16 , respectively (Scheme 3). - Photochemical reaction of the tricyclic vinylcyclopropane 6 with Fe(CO)₅ gave the σ,π-bonded iron complexes 17 and 18 . Heating of 17 at 80° resulted in a loss of one mol of carbon monoxide to give 18 in quantitative yield. Oxidative degradation of 17 with ceric ammonium nitrate in ethanol afforded the polycyclic lactones 19 and 20 by a novel type of reaction (Scheme 4). - The tricyclic ketone 21 was thermally converted into the α,β-unsaturated ketone 22 via a homosigmatropic [1,5]-H-shift. The configuration at C(7) of 22 was confirmed to be same as that of 11 (CH₃? C(9) in an exo position) by chemical conversions: 22 was reduced with NaBH₄ to alcohol 23 which, in turn, was dehydrated with POCl₃/pyridine to 11 (Scheme 5). Reaction of ketone 21 with Mo(CO)₆ gave the α,β-unsaturated ketone 25 and a cage compound X , whose structure was not fully elucidated. - Reaction of the polycyclic epoxide 26 with Fe₂(CO)₉ or Mo(CO)₆ yielded the allyl alcohol 27 in a novel type of reaction. The epoxides 29 and 32 were similarly converted into the corresponding allyl alcohols 30 and 33 , respectively (Scheme 6).     

Koordinationschemie tripodaler Triisocyanid-Liganden: Synthese von Komplexen des Typs CH3C[CH2NC-M(CO)x]3 (M = Cr,W, χ = 5; M = Fe, χ = 4) und Kristallstruktur von CH3C[CH2NC-W(CO)5]3

The triisocyanide ligand CH₃C(CH₂NC)₃, time, reacts with metal carbonyls M(CO)_x (M = Cr, W, χ = 6; M = Fe, χ = 5) to give the triply metal carbonyl substituted complexes CH₃C[CH₂NCM(CO)_x]₃ (M = Cr, W, χ = 5; M = Fe, χ = 4). CH₃C[CH₂NCW(CO)₅]₃ was characterized by an X-ray structure determination.     

Synthese,Strukturuntersuchung und Reaktionen Phosphansubstituierter Derivate von Fe3(CO)9(μ3-CF)2

Syntheses, Structure Determination and Reactions of Phosphine Substituted Derivatives of Fe₃(CO)₉(μ₃-CF)₂ Photolysis of Fe₃(CO)₉(μ₃-CF)₂ 1 in the presence of acetonitrile 2a or benzoenitrile 2b results in the substitution of a single carbonyl ligand by a nitrile ligand yielding Fe₃(CO)₈(CH₃CN)(μ₃-CF)₂ 3a and Fe₃(CO)₈(C₆H₅CN)(μ₃-CF)₂ 3b, respectively. The acetonitrile ligand in 3a can be easily replaced by trimethyl-phosphine 4a or triphenylphosphine 4b . The monosubstituted compounds Fe₃(CO)₈(PR₃)(μ₃-CF)₂5, R = CH₃ a, R = C₆H₅, b are obtained as major products besides a small amount of the disubsituted products Fe₃(CO)₇(PR₃)₂(μ₃-CF)₂ 6. The structure of 5a has been elucidated by a single crystal X-ray structure determination. Thermal ligand substitution in 1, however, results in the formation of a mixture of mono-, disubstituted, and trisubstituted products, in which 6b is the major product for diphenylphosphine. 5a reacts with ethyne 7 forming a phosphine substituted diferra-allyl-cluster Fe₃(CO)₇(PR₃)(μ₃-CF)(μ₃? CF? CH? CH) 8. The structure of one isomere of 8 has been determinated by X-ray crystallography.     

POSSIBLE HYDRIDE AND METHIDE TRANSFER REACTIONS: REACTIONS OF Fe(CO)4R−(R = H,CH3) AND W(CO)5R− (R = H,CH3, Cl,Br, I) WITH METAL CARBONYL CATIONS

Abstract

Reactions of metal carbonyl cations (M(CO)₆ ⁺, M = Mn, Re) with hydride-, methide- or halide-containing metal carbonyl anions (Fe(CO)₄R^?, R = H, Me; W(CO)₅R^?, R = H, Me, Cl, Br, I) produce products that indicate several mechanisms are operative. Reactions of the halo-tungsten complexes produce neutral, solvated tungsten complexes, W(CO)₅(CH₃CN) and W(CO)₄(CH₃CN)₂ and M(CO)₅X in a reaction that appears to be initiated by decomposition of W(CO)₅X^?. In contrast, the tungsten hydride and methide complexes react, predominantly, by transfer of the hydride or methide to a carbonyl of the cation at a much faster rate. The iron hydride and methide complexes react by iron-based nucleophilicity involving a two-electron process.     

Reaction of 1,3-Thiazole-5(4H)-thiones with 1,2-Epoxycycloalkanes: Formation of Spirocyclic 1,3-Oxathiolanes

Treatment of solutions of 1,3-thiazole-5(4H)-thiones 1 in CH₂Cl₂ at room temperature with BF₃⋅Et₂O and 1,2-epoxycyclohexane (7-oxabicyclo[4.1.0]heptane; 2a ) or 1,2-epoxycyclopentane (6-oxabicyclo[3.1.0]hexane; 2b ) yielded mixtures of diastereoisomeric spirocyclic 1,3-oxathiolanes ( 3 / 4 and 8 / 9 , respectively). In addition, the corresponding 1,3-dithiolane 6 was formed as a minor product in the reaction of 4,4-dimethyl-2-phenyl-1,3-thiazole-5(4H)-thione ( 1a ) with 2a . The structures of the different types of products have been established by X-ray crystal-structure analysis. An ionic two-step mechanism via nucleophilic ring-opening of the complexed oxirane by the attack of the thiocarbonyl S-atom is proposed. This proposal is supported by the formation of the propellane 10 with a Wagner-Meerwein rearrangement as the key step.     

4(3H)-Quinazolinones containing heterocyclic group in position 3

The corresponding 2,3-substituted 4(3H)-quinazolinones were obtained in the reactions of 2-methyl- and 2-phenyl-4-oxo-3,1-benzoxazines with 1-amino-1,2,4-triazole, 4-amino-2,3-dimethyl-1-phenyl-5-pyrazolone, 2-amino-5-ethyl-1,3,4-thiadiazole, 3-amino-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazole, 1-amino-3-cyano-4,6-dimethyl-2-pyridone, and 1-amino-3-cyano-6-phenyl-4-trifluoromethyl-2-pyridone. The formation of N-benzolyanthranilamides in the reactions of 2-phenyl-4-oxo-3,1-benzoxazine with 2-amino-5-ethyl-1,3,4-thiadiazole and 1-amino-3-cyano-6-phenyl-4-trifluoromethyl-2-pyridones was exceptional. The structures of two of the products have been confirmed by X-ray crystallography.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 936–943, July, 2000.