Synthesis of new metal-free 1,2,4,5,9,10,12,13-octaaza[16]annulene derivatives using the reaction of vinamidinium salts with thiocarbohydrazide

A new series of marcocyclic ligands, 1,2,4,5,9,10,12,13-octaaza[16]annulene derivatives were synthesized by using the condensation reaction of the correspondingly [2+2] 2-heteroaryl-substituted vinamidinium salts or phenyl vinamidinium salts and derivatives or halo-substituted vinamidinum salt [1A-10A] with thiocarbohydrazide in ethanolic medium under mild condition. Metal complexes were formed by reacting of ethanolic solution of Co, Ni, and Zn with macrocyclic ligand in ethanolic medium under mild condition. Purposed complexes have been characterized with the help of elemental analyses, comparative absorption band of ν(C=N), mass, and NMR. Geometry and complex formulation are out of scope of this work. The biological activities of carohydrazide and thiocarbohydrazide base of the ligands and purposed complexes such as antimicrobial, antitumor, and insecticides have attracted significant attention in bioorganic chemistry.     

Synthesis of heierocyclic compounds from 2-phenyl-1, 2,3-triazole-4-formylhydrazine

2-Phenyl-1, 2, 3-triazole-4-formylhydrazine (2) was prepared by hydrazinolysis of the corresponding ester 1. Reaction of 2 with CS2/KOH gave the oxadiazole derivatives (3) which via, Mannich reaction with different dialkyl amines furnished 3-N, N-dialkyl derivatives (4a-c). Also, condensation of 2 with appropriate aromatic acid in POCl3 yielded oxadiazole derivatives (5a-c), or with aldehydes and ketones afforded hydrazones (6a-c). Cyclization of (6a-c) with acetic anhydride gave the desired dihydroxadiazole derivatives (7a-c). On the other hand, reaction of dithiocarbazate (8) with hydrazine hydrate gave the corresponding triazole derivative (9) which on treatment with carboxylic acids in refluxing POCl3 yielded s-triazole[3,4-b]-1, 3, 4-thiadiazole derivatives (10a-b). The structures of all the above compounds were confirmed by means of IR, 1H NMR, MS and elemental analysis.     

Synthesis of new derivatives of 1,5,9,13-tetraaza[16]annulene using 2-substituted vinamidinium salts

New 7,15-dibromo-, 7,15-di(bromomethyl)-, and 7,15-di[4-(bromomethyl)phenyl]-1,5,9,13-tetraaza[16]annulene derivatives are synthesized via the condensation reaction of 2-substituted vinamidinium salts [2-substituted 3-(dimethylamino)-N,N-dimethyl-2-propen-1-aminium salts] with 1,8-diaminonaphthalene in acetonitrile/acetic acid. The ultraviolet spectral behavior of these compounds is examined in DMSO.     

Efficient synthesis of highly functionalized dihydropyrido[2,3-d]pyrimidines by a double annulation strategy from alpha-alkenoyl-alpha-carbamoyl ketene-(S,S)-acetals

A convenient and efficient synthesis of highly functionalized dihydropyrido[2,3-d]pyrimidines via a double [5 + 1] annulation strategy starting from easily available alpha-alkenoyl-alpha-carbamoyl ketene-(S,S)-acetals 1 and cheap reagents (NH4OAc, DMF, and POCl3) has been developed. In the first step of the double annulation route, 2-amino-3-carbamoyl-5,6-dihydro-4-pyridones 2 were created in high to excellent yields by a formal [5C + 1N] annulation reaction of ketene-(S,S)-acetals 1 with ammonia (from ammonium acetate). In the second step of the double annulation strategy, the highly functionalized dihydropyrido[2,3-d]pyrimidine derivatives, 7,8-dihydropyrido[2,3-d]pyrimidin-4(3H)-ones 3 (when R1 = aryl) and 7,8-dihydropyrido[2,3-d]pyrimidines 4 (when R1 = H), were constructed, respectively, in fair to good yields by reacting 2 with excessive Vilsmeier reagent (DMF/POCl3). A mechanism involved in the second [5 + 1] annulation step, including a formal [5 + 1] annulation and accompanied chlorovinylation, chloroformylation, amination, and aromatization reactions, is proposed.     

Synthesis of fused systems containing an angular nitrogen atom from substituted 2-benzyl-4-hydrazinopyridimines

The condensation of substituted 2-benzyl-4-hydrazinopyrimidines with phenylpyruvic acid gave the corresponding hydrazones, which cyclize upon the action of POCl, to give derivatives of pyrimido[6,1-c][1,2,4]-triazine. The substituted 2-benzylpyrimidinylhydrazides of some carboxylic acids react with POCl, to give 1,2,4-triazolo[4,3-c]pyrimidines. The reaction of 7-benzyl-5-methyl-l-phenyl-1,2,4-triazolo[2,3-c]pyrimidine with sodium ethylate leads to rearrangement and formation of 7-benzyl-5-methyl-2-phenyl-1,2,4-triazolo[2,3-c]pyrimidine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 225–229, February, 2000.     

An electrochemical study of PCl3 and POCl3 in the room temperature ionic liquid [C4mpyrr][N(Tf)2

Voltammetric studies of PCl3 and POCl3 have not been reported in the literature to date, probably due to the instability of these molecules in conventional aprotic solvents giving unstable and irreproducible results. From a previous study [Amigues et al. Chem. Commun. 2005, 1-4], it was found that ionic liquids have the ability to offer a uniquely stable solution phase environment for the study of these phosphorus compounds. Consequently, the electrochemistry of PCl3 and POCl3 has been studied by cyclic voltammetry on a gold microelectrode in the ionic liquid [C4mpyrr][N(Tf)2] (1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide). For both compounds, reduction and oxidation waves were observed and a tentative assignment of the waves is given. For PCl3, the reduction was thought to proceed via the following mechanism: PCl3 + e- <=> PCl3-, PCl3- <=> Cl- + P*Cl2, and Cl- + PCl3 <=> PCl4-. For POCl3, the suggested reduction mechanism was analogous to that of PCl3: POCl3 + e- <=> POCl3-, POCl3- <=> Cl- + P*OCl2, and Cl- + POCl3 <=> POCl4-. In both cases P*Cl2 and P*OCl2 are likely to engage in further reactions. Potential step microdisk chronoamperometry was carried out on the reductive waves of PCl3 and POCl3 to measure diffusion coefficients and number of electrons transferred. It was found that the diffusion of PCl3 was unusually slow (3.1 x 10(-12) m2 s(-1)): approximately 1 order of magnitude less than that for POCl3 (2.2 x 10(-11) m2 s(-1)). For both PCl3 and POCl3, a "split wave" was observed, with an overall electron count of 1. This observation is shown to be consistent with and to "fingerprint" the mechanisms proposed above.     

Synthesis and characterization of new derivatives of bis(1,4-diazepinium) salts and bis(γ-substituted pentamethine cyanine(dyes using vinamidinium salt

The preparation of several bis(1,4-diazepinium) salts from the reaction of three 1,2-diamines with a bis(vinamidinium) salt is described. Bis(γ-substituted pentamethine cyanine(dyes are also prepared from the reaction of vinamidinium salt with 1,2-dimethylquinolinium perchlorate and 1,2,3,3-tetramethyl-3H-indolium perchlorate. Data from elemental analyzes, IR, ¹H-NMR, ¹³C-NMR, and mass spectra (MS) confirm the molecular structure of the obtained products.     

The first noncoordinated phosphonium diylide, [Me2P(C13H8)2]-, and its ylidic and cationic counterparts: synthesis, structural characterization, and interaction with the heavy group 2 metals

Treatment of potassium or lithium fluorenide with MePCl2 generates the organophosphine MeP(C13H9)2, which on reaction with methyl iodide produces the phosphonium species [Me2P(C13H9)2]I in 74% yield. In the solid state, H...I contacts of < 3.3 A help generate a layered structure in which the fluorenyl rings are nearly parallel. On subsequent reaction of [Me2P(C13H9)2]I with either KH or K[N(SiMe3)2], the corresponding neutral phosphoylide, Me2P(C13H9)(C13H8), forms in 67% yield and was structurally characterized. The phosphonium iodide [Me2P(C13H9)2]I was allowed to react with Ae[N(SiMe3)2]2 (Ae = Ca, Ba), and the product from the reaction with the calcium complex was structurally identified as the salt [CaI(thf)5][Me2P(C13H8)2]. The anion, which is outside the coordination sphere of the calcium, represents the first structurally authenticated example of a free phosphonium diylide. The P-C(ylidic) bond length of 1.748(4) A reflects some partial multiple bond character. 1H and 31P NMR spectra suggest that the barium analogue is similar. Density functional theory calculations were performed on representative phosphonium diylides as an aid to interpreting the bonding in this class of compounds. Despite the strong electrostatic attraction that usually drives metal-ligand binding in highly ionic systems, calcium and barium prefer to coordinate to a single iodide ion and several neutral oxygen donors rather than to the charged diylide.     

Phosphate Doubly Capped Tetrahomodioxacalix[6] arene

A bisphosphate-bridged tetrahomodioxacalix[6] arene with a C2v symmetry at the ambient temperature was obtained by the reaction of tetrahomodioxacalix[6] arene with POCl3。     

Facile synthesis of novel 3-substituted pyrido[1,2-a]pyrimidinium salts using vinamidinium salts

Pyrido[1,2-a]pyrimidinium salt derivatives 2a–f were prepared in good yields by condensation of 2-aminopyridine with 2-substituted vinamidinium salt derivatives 1a–f. The purity and the structure of the synthetized compounds were ascertained by elemental analysis, mass spectrometry, infrared, and NMR (¹H and ¹³C 400?MHz) spectroscopy.     

An improved synthesis of [2.2.3]cyclazines from 3H-pyrrolizines

[2.2.3]Cyclazines are obtained in moderate yields by reaction of 3$\text{H}$-pyrrolizines bearing conjugative substituents (Ph or CO₂Me) with vinamidinium salts in the presence of strong bases. Syntheses of the previously unknown 2-phenyl-3$\text{H}$-pyrrolizine and 1-methoxycarbonylcyclopenta [$\text{h}$] [2.2.4] cyclazine are also described.     

Demonstrating the synergy of synthetic, mechanistic, and computational studies in a regioselective aniline synthesis

Tri- and tetrasubstituted anilines are formed in good to excellent yields by the addition of ketones to vinamidinium salts (up to 98%). The reaction proceeds via the formation of dienone intermediates, which react to form an enamine with the liberated amine. In the case of a nitro, or dimethylaminomethylene substituent, the enamines undergo a facile electrocyclic ring closure to form a cyclohexadiene, which goes on to form anilines with a high degree of selectivity (up to 50:1) with a minor competing pathway proceeding via the enol providing phenols. Competition experiments using isotopic substitution reveal that the rate determining step en route to dienone is enol/enolate addition to the vinamidinium salt, which is characterized by an inverse secondary isotope effect (k(H/D) 0.7-0.9). Computational studies have been used to provide a framework for understanding the reaction pathway. The original proposal for a [1,5]-H shift was ruled out on the basis of the calculations, which did not locate a thermally accessible transition state. The minimum energy conformation of the enamine is such that a facile electrocyclic ring closure is ensured, which is corroborated by the experimental studies. A framework for understanding the reaction pathway is presented.     

1,2-双(四甲基环戊二烯基)四甲基二硅烷与六碳基钼的反应

1,2-双(四甲基环戊二烯基)四甲基二硅烷与正丁基锂作用生成(四甲基二硅撑)双(四甲基环戊二烯基负离子盐),后者随即与六碳基钼反应形成1,1'-(四甲基二硅撑)双(四甲基环戊二烯基铝负离子盐)-(Me₂SiSiMe₂)[Me₄CpMo(CO)₃-Li⁺]₂(I),I与冰醋酸作用,随即分别与CCl₄,NBS及I₂反应,生成相应的铝卤化合物(Me₂SiSiMe₂)[Me₄CpMo(CO)₃X]₂[X=Cl(1),Br(2),I(3)].I与CH₃I反应,在钼原子上发生烃基化,得到产物(Me₂SiSiMe₂)[Me₄CpMo(CO)₃Me]₂(4);I与单质I₂直接反应,生成脱硅桥产物Me₄Cp(CO)>₃I(5).经元素分析、IR及¹HNMR表征了化合物1-5的结构。     

Novel cation [N(SO2NMe3)2]+ and its synthesis and crystal structure. Dichloride of imido-bis(sulfuric) acid HN(SO2Cl)2. Part 1. Crystal structures of KN(SO2Cl)2.(1/2)CH3CN, KN(SO2Cl)2.(1/6)CH2Cl2, and [PCl4][N(SO2Cl)2

Several salts of bis(chlorosulfonyl)imide HN(SO2Cl)2 (1), namely, two solvates of its potassium salt, KN(SO2Cl)2.(1/2)CH3CN (1K1), KN(SO2Cl)2.(1/6)CH2Cl2 (1K2), and its tetrachlorophosphonium salt, [PCl4][N(SO2Cl)2] (2), were prepared and structurally characterized. The reaction of HN(SO2Cl)2 with Me3N gives the [N(SO2Cl)2]- salt of a novel cation, [N(SO2NMe3)2]+. This cation is analogous to the [HC(SO2NMe3)2]+ cation, but in contrast to the latter, it is fairly stable to hydrolysis. The salt [N(SO2NMe3)2]+[N(SO2Cl)2]- (3) can be converted into salts of other anions by being treated with diluted aqueous solutions of the respective acids, and thus NO3-, Cl-.H2O, SeO3(2-), CH3COO-, HSO4-, (COO)2(2-) salts were prepared. Treatment of 3 with concentrated HNO3 gave the [N(SO2NMe3)2]+ [O2NO-H-ONO2]- salt, and the addition of an HCl-acidified FeCl3 aqueous solution yielded the FeCl4- salt. Methanolysis resulted in the formation of MeOSO3- and [MeOSO2NSO2OMe]- salts. All salts have been characterized by chemical analysis, vibrational spectroscopy, and X-ray structure determinations.     

Phase Transfer Catalyzed Synthesis of 1, 2-Bis[（3-aryl）-s-triazolo- [3, 4-b]-[1, 3, 4]thiadiazole-6-yl]ethanes

s-Triazolo[3, 4-b]-[1, 3, 4]thiadiazole derivatives have been paid attractive attention due to their significantly biological activities1-5, including antibacterial, antifungal, anticancer, relaxing vascular activities. They are highly important heterocyc…     

Reactions of POxCly- ions with H and H2 from 298 to 500 K

Rate constants and product branching ratios for POxCly- ions reacting with H and H2 were measured in a selected ion flow tube (SIFT) from 298 to 500 K. PO2Cl-, PO2Cl2-, POCl2-, and POCl3- were all unreactive with H2, having a rate constant with an upper limit of <5 x 10(-12) cm3 s(-1). PO2Cl2- did not react with H atoms either, having a similar rate constant limit of <5 x 10(-12) cm3 s(-1). The rate constants for PO2Cl-, POCl2-, and POCl3- reacting with H showed no temperature dependence over the limited range of 298-500 K and were approximately 10-20% of the collision rate constant. Cl abstraction by H to form HCl was the predominant product channel for PO2Cl-, POCl2-, and POCl3-, with a small amount of Cl- observed from POCl2- + H. Reactions of O2 and O3 with the POCl- products ions from the reaction of POCl2- + H were observed to yield predominantly PO3- and PO2-, respectively. POCl- reacted with O2 and O3 with rate constants of 8.9 +/- 1.1 x 10(-11) and 5.2 +/- 3.3 x 10(-10) cm3 s(-1), respectively. No associative electron detachment in the reactions with H atoms was observed with any of the reactant ions; however, detachment was observed with a PO- secondary product ion at high H atom concentrations. Results of new G3 theoretical calculations of optimized geometries and energies for the products observed are discussed.     

Chemistry and electrochemistry of the heterodinuclear complex ClPd(dppm)2PtCl: a M-M' bond providing site selectivity

The heterodinuclear d(9)-d(9) title compound 1, whose crystal structure has been solved, reacts with dppm [bis(diphenylphosphino)methane] in the presence of NaBF4 to generate the salt [ClPd(mu-dppm)2Pt(eta(1)-dppm)][BF4] (2a), which contains a Pt-bound dangling dppm ligand. 2a has been characterized by 1H and 31P NMR, Fourier transform Raman [nu(Pd-Pt) = 138 cm(-1)], and UV-vis spectroscopy [lambda(max)(dsigma-dsigma*) = 366 nm]. In a similar manner, [ClPd(mu-dppm)2Pt(eta(1)-dppm=O)][BF4] (2b), ligated with a dangling phosphine oxide, has been prepared by the addition of dppm=O. The molecular structure of 2b has been established by an X-ray diffraction study. 2a reacts with 1 equiv of NaBH4 to form the platinum hydride complex [(eta(1)-dppm)Pd(mu-dppm)2Pt(H)][BF4] (3). Both 2a and 3 react with an excess of NaBH4 to provide the mixed-metal d(10)-d(10) compound [Pd(mu-dppm)3Pt] (4). The photophysical properties of 4 were studied by UV-vis spectroscopy [lambda(max)(dsigma-dsigma*) = 460 nm] and luminescence spectroscopy (lambda(emi) = 724 nm; tau(e) = 12 +/- 1 micros, 77 K). The protonation of 1 and 4 leads to [ClPd(mu-dppm)2(mu-H)PtCl]+ (5) and 3, respectively. Stoichiometric treatment of 1 with cyclohexyl or xylyl isocyanide yields [ClPd(mu-dppm)2Pt(CNC6H11)]Cl (6a) and [ClPd(mu-dppm)2Pt(CN-xylyl)]Cl (6b) ligated by terminal-bound CNR ligands. In contrast, treatment of 1 with the phosphonium salt [C[triple bond]NCH2PPh3]Cl affords the structurally characterized A-frame compound [ClPd(mu-dppm)2(mu-C=NCH2PPh3)PtCl]Cl (6c), spanned by a bridging isocyanide ligand. The electrochemical reduction of 2a at -1.2 V vs SCE, as well as the reduction of 5 in the presence of dppm, leads to a mixture of products 3 and 4. Further reduction of 3 at -1.7 V vs SCE generates 4 quantitatively. The reoxidation at 0 V of 4 in the presence of Cl- ions produces back complex 2a. The whole mechanism of the reduction of 1 has been established.     

Bischler-Napieralski Cyclization-N/C-Alkylation Sequences for the Construction of Isoquinoline Alkaloids. Synthesis of Protoberberines and Benzo[c]phenanthridines via C-2'-Functionalized 3-Arylisoquinolines(1)

Efficient synthetic routes to isoquinoline alkaloids of the protoberberine and benzo[c]phenanthridine classes are reported. The key transformations are derived from the intramolecular cyclization of C-2'-functionalized N-(1,2-diarylethyl)amides or enamides via 3-arylisoquinoline derivatives. Thus, under Bischler-Napieralski reaction conditions (PCl(5), nitrile as solvent, room temperature) N-(1,2-diarylethyl)amides 12 regioselectively yielded 2,3-disubstituted 13,14-dihydroprotoberberinium salts 20, a scarcely studied oxidation state in this class of alkaloids. Subsequent reduction of the iminium bond gave the known coralydine (21a) and O-methylcorytenchirine (21b) and their 8-phenyl analogue 21c. The one-pot preparation of these dihydroprotoberberinium salts 20 is shown to proceed with cleavage of the silyl ether and immediate halogenation of the resulting hydroxyl group, followed by cyclization of the obtained N-(1,2-diarylethyl)amide 18 to a 3,4-dihydroisoquinoline derivative 19 and subsequent intramolecular in situ N-alkylation of the latter imine. Ready access to planar 8,9-dialkoxylated benzo[c]phenanthridinium salts is also described. Condensation of ketoester 23 with benzylamine in the presence of titanium(IV) chloride, followed by acetylation, afforded a mixture of naphthylamide 24 and (E)-enamide 25. Both enamides were efficiently cyclized by POCl(3). While the planar benzo[c]phenanthridinium salt 26 was directly produced from 24, the (E)-enamide 25 gave the 3-arylisoquinolinium salt 27, which was reduced and intramolecularly C-alkylated to yield the tetracyclic nucleus of these alkaloids.     

Synthesis, structure and antifungal activity of new 3-[(5-aryl-1,3,4-oxadiazol-2-yl)methyl]benzo[d]thiazol-2(3H)-ones

A series of new 3-[(5-aryl-1,3,4-oxadiazol-2-yl)methy])benzo[d]thiazol-2(3H)-ones were synthesized by reaction of (5-substituted-2-oxobenzothiazolin-3-yl)-acetohydrazide with various aromatic acids in POCl(3) under reflux conditions. The structures of the title compounds were confirmed by 1H-NMR, 13C-NMR, IR, MS and elemental analysis. Furthermore, the structure of compound 4i was determined by single-crystal X-ray diffraction. The preliminary bioassy results indicated that some of them showed moderate inhibition activity against Colletotrichum orbiculare, Botrytis cinerea and Rhizoctonia solani.     

Eta 1 and eta 2 Coordination of 1-amino-closo-dodecaborate

The reaction of the sodium salt of 1-amino-closo-dodecaborate [Na]2[NH2-B12H11] ([Na]2[1]) with [Au(PPh3)Cl] and [Ni(THF)2(Br)2] led to eta 1(N) coordination of 1in [Na][Au(PPh3)(NH2-B12H11)] (2) and [Na]6[Ni(NH2-B12H11)4] (3), respectively. Furthermore, eta 2(N,BH) coordination of was found in [MePPh3][Rh(PPh3)2(NH2-B12H11)] (4), which was synthesized by the reaction of [MePPh3][Na][1] with [Rh(PPh3)3Cl]. All compounds were characterized by single crystal X-ray diffraction and heteronuclear NMR spectroscopy.