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This work reports the ambient temperature synthesis and structural characterisation of six new first row transition metal acetylenedicarboxylate coordination polymers. The Co and two Ni compounds adopt structures in which the octahedral metals are connected into 1D chains via the acetylenedicarboxylate ligand. In contrast the Mn and two Zn compounds adopt 3D metal-organic frameworks; while the Mn compound is non-porous the two Zn structures contain dimeric or trimeric clusters connected into frameworks that are potentially porous. These two anionic metal-organic frameworks are, however, charged balanced by cations siting in their pores which greatly reduces the ability to access their porosity.

Anhydrous EuII–acetylenedicarboxylate (EuADC; ADC2− = −O2C‐C≡C‐CO2 −) was synthesized by reaction of EuBr2 with K2ADC or H2ADC in degassed water under oxygen‐free conditions. EuADC crystallizes in the SrADC type structure (I41/amd, Z=4) forming a 3D coordination polymer with a diamond‐like arrangement of Eu2+ nodes (msw topology including the connecting ADC2− linkers). Deep orange coloured EuADC is stable in air and starts decomposing upon heating in an argon atmosphere only at 440 °C. Measurements of the magnetic susceptibilities (μ eff=7.76 μB) and 151Eu Mössbauer spectra (δ=−13.25 mm s−1 at 78 K) confirm the existence of Eu2+ cations. Diffuse reflectance spectra indicate a direct optical band gap of E g=2.64 eV (470 nm), which is in accordance with the orange colour of the material. Surprisingly, EuADC does not show any photoluminescence under irradiation with UV light of different wavelengths. Similar to SrADC, EuADC exhibits a negative thermal volume expansion below room temperature with a volume expansion coefficient α V=−9.4(12)×10−6 K−1., Multifaceted! Orange coloured Eu(C4O4), the anhydrous EuII salt of acetylenedicarboxylic acid, has many interesting properties: it is stable in air for months, and upon heating in an inert atmosphere decomposition only starts at 440 °C. Below room temperature it shows a negative thermal volume expansion (NTE) and although containing EuII it does not exhibit any luminescence even at 10 K.

A strategy was developed to obtain from acetylenedicarboxylic acid either an acetylenedicarboxylate-based ZrIV metal-organic framework (MOF) with fcu topology or a halo-functionalized-MOF-801 through in situ ligand hydrohalogenation. The new materials feature exceptionally high hydrophilicity and CO2 /H2 adsorption energetics. The acetylenedicarboxylate linker and its functionalizable triple-bond discloses its potential in the engineering of microporous materials with targeted properties.

The crystal structures of 3∞[RE2(ADC)3(H2O)6]·2H2O (RE = Pr, Nd, Sm, Eu, Tb, Dy) were solved and refined from X-ray single crystal data. They crystallize in a structure type already known for RE = La, Ce and Gd (P1, no. 2, Z = 2), which is characterized by REO9 polyhedra forming dimeric units being the nodes of a 3D framework structure linked by ADC2– anions (–O2C–C≡C–CO2– = acetylenedicarboxylate). From synchrotron powder diffraction data it was shown that isostructural coordination networks are formed for RE = Ho, Er, Y, whereas for RE = Tm, Yb, Lu a new structure type crystallizing in a highly complex crystal structure with a large orthorhombic unit cell is found. All compounds are obtained by slow evaporation of an aqueous solution containing RE(OAc)3·xH2O and acetylenedicarboxylic acid (H2ADC). The coordination networks of composition 3∞[RE2(ADC)3(H2O)6]·2H2O were thoroughly investigated by thermal analysis and for RE = Eu, Tb, a strong red and green photoluminescence was observed and investigated by means of UV/Vis spectroscopy.

The phosphine-catalyzed Michael addition/intramolecular Wittig reaction between dialkyl acetylenedicarboxylate and amino-carbaldehyde or amino-ester derivatives has been developped. This reaction can be rendered catalytic in phosphine by the in situ chemoselective reduction of the phosphine oxide with silane. This methodology enables rapid access to a variety of nitrogen-containing heterocycles, which are present in numerous natural products and/or bioactive compounds. Either classical heating or microwave conditions give access to the desired products in good yields (15 examples, 60-99% yields). This catalytic methodology is further applicable to the synthesis of enantioenriched 1H-pyrrole derivatives, with the use of chiral phosphines. Finally, we successfully extended the reaction to the synthesis of polysubstituted cyclopentenone, starting from butane-2,3-dione as substrate.

A series of oxocyclopenta[c]chromenes were synthesized via three component reaction of 4-hydroxycumarin, dialkyl acetylenedicarboxylate, α-bromo ketones, and triphenylphosphine in the presence of catalytic amount of Fe3O4 magnetic nanoparticles (MNPs) (15 mol%) under solvent-free conditions at 70°C. Facile, green, easy separation of product and catalyst, and high yields of products are advantages of these reactions.

Hyperpolarized [1‐13C]fumarate is a promising magnetic resonance imaging (MRI) biomarker for cellular necrosis, which plays an important role in various disease and cancerous pathological processes. To demonstrate the feasibility of MRI of [1‐13C]fumarate metabolism using parahydrogen‐induced polarization (PHIP), a low‐cost alternative to dissolution dynamic nuclear polarization (dDNP), a cost‐effective and high‐yield synthetic pathway of hydrogenation precursor [1‐13C]acetylenedicarboxylate (ADC) was developed. The trans‐selectivity of the hydrogenation reaction of ADC using a ruthenium‐based catalyst was elucidated employing density functional theory (DFT) simulations. A simple PHIP set‐up was used to generate hyperpolarized [1‐13C]fumarate at sufficient 13C polarization for ex vivo detection of hyperpolarized 13C malate metabolized from fumarate in murine liver tissue homogenates, and in vivo 13C MR spectroscopy and imaging in a murine model of acetaminophen‐induced hepatitis., Toward clinical translation: Hyperpolarized [1‐13C]fumarate was prepared by the trans‐selective para‐hydrogenation of [1‐13C] acetylenedicarboxylate precursor using a [Cp*Ru(MeCN)3]PF6 catalyst. The feasibility of in vivo imaging of necrotic cell death by 13C MRI of PHIP‐hyperpolarized exogenously injected fumarate metabolism was demonstrated in an acetaminophen‐induced hepatitis mouse.

Single crystals of dilithium-acetylenedicarboxylate-dihydrate, Li2ADC·2H2O (1), were isolated from a solid product formed by isothermal evaporation of an aqueous solution of LiOH und acetylenedicarboxylic acid (H2ADC). 1 crystallizes in the triclinic space group P1 with Z = 2. LiO4 tetrahedra are interconnected by ADC2– anions and water molecules to form a 3D polymeric structure. Coupled TGA and DTA measurements show that 1 loses its two water molecules above 100 °C. Heating a polycrystalline sample of 1 at 140 °C for 2 h in an argon atmosphere leads to a significant change of the powder diffraction pattern indicating the formation of the new anhydrous coordination polymer dilithium-acetylenedicarboxylate, Li2ADC (2). Its crystal structure was solved and refined from X-ray powder diffraction data. 2 crystallizes in the orthorhombic space group Fddd (Z = 8). LiO4 tetrahedra are interconnected by ADC2– anions to form a 3D polymeric structure.

The three component condensation reactions involving 2-methylbenzothiazole or 2,5-dimethylbenzothiazole, dialkyl acetylenedicarboxylate, and 2,6-dimethyl phenol or 2,6-di-tert-butylphenol constitute a novel and one-pot synthesis of tetrahydropyrrolo[1,2-a]-2-methylbenzothiazoles-3-spiro-1′-cyclohexa-2′,5′-dien-4′-one-4,5-dicarboxylate derivatives in good yields. The reactions proceeded at room temperature without using any catalyst. This method is very useful to functionalize benzothiazole derivatives in a one-pot operation.

The effects of bent linkers in diynes on the efficiency and selectivity of intermolecular macrocyclization by the rhodium-catalyzed sequential cross-cyclotrimerization of L-shaped diynes and di-tert-butyl acetylenedicarboxylate was investigated. A bulky triethylsilyl-protected cyclohexa-1,4-dienediol-linked diyne reacted with di-tert-butyl acetylenedicarboxylate to give the corresponding 16-membered macrocycle as well as the 12-membered macrocycle. Aromatization of the thus-obtained 12-membered macrocycle through desilylation followed by reductive aromatization with SnCl2 and HCl afforded a [12]cycloparaphenylenehexacarboxylate. The use of a conformationally flexible methoxymethyl-protected cyclohexanediol-linked diyne increased the yield of the corresponding 16-membered macrocycle, although oxidative aromatization leading to the corresponding cycloparaphenylenes was unsuccessful.

An efficient multi-component synthesis of highly functionalized 2,2′-bifurans and 2-(thiophen-2-yl)furans is described. A mixture of furan- or thiophene-2-carbonyl chloride, an isocyanide, and a dialkyl acetylenedicarboxylate undergoes a smooth addition reaction in dry CH2Cl2 at ambient temperature to produce 2-amino-5-(4-chlorofuran-2-yl)furan-3,4-dicarboxylates and 2-amino-5-(4-chlorothiophen-2-yl)furan-3,4-dicarboxylates. A single-crystal X-ray-analysis of a derivative conclusively confirms the structure of these 2,2′-bifurans and 2-(thiophen-2-yl)furans. A novel electrophilic aromatic substitution reaction can justify the formation of the Cl-substituted furan or thiophene rings.

The four-component reactions of anilines, dialkyl acetylenedicarboxylate, acenaphthenequinone, and dimedone (or cyclohexane-1,3-dione) in acetic acid provided an efficient synthetic procedure for the functionalized spiro[acenaphthylene-1,2′-quinoline] derivatives in good yields. This reaction has the advantages of using common starting material, mild reaction conditions, and operational simplicity.

The one-pot four-component reaction of benzohydrazide, acetylenedicarboxylate, aromatic aldehydes and malononitrile in ethanol with triethylamine as base catalyst afforded functionalized 1-benzamido-1,4-dihydropyridines in satisfactory yields. Under similar conditions, picolinohydrazide or nicotinohydrazide can also be successfully utilized in the reactions to give corresponding functionalized 1,4-dihydropyridines. 1H NMR data indicated that an equilibrium of cis/trans-conformations exist in 1-benzamido-1,4-dihydropyridines.

A simple synthetic protocol has been developed for the efficient synthesis of structurally diverse 3′-aryl-2′-styryl-2′,3′-dihydrospiro[indoline-3,6′-[1,3]oxazine]-4′,5′-dicarboxylate derivatives through readily accessible three-component reactions of α,β-unsaturated N-arylaldimines, dialkyl acetylenedicarboxylate, and N-alkylisatins. When simple N-arylaldimines were utilized in the reactions, the corresponding 2′,3′-diaryl-2′,3′-dihydrospiro[indoline-3,6′-[1,3]oxazine]s were obtained in good yields. This reaction provides a potential synthetic application of the reactive 1,4-dipolar intermediates generated from the reaction of aromatic imines with electron-deficient alkynes.

An effective route to 2-oxopyrrole-fused 1,n-diazaheterocyclic compounds and substituted 2-oxopyrroles is described. This involves reaction of 1,n-diamines or monoamines 1 and nitroketene dithioacetal (1,1-di(methylthio)-2-nitroethene) in the presence of dialkyl acetylenedicarboxylate 2 in EtOH to give 2-oxopyrrole derivatives 3 in good yields (Table 1). The structures were corroborated spectroscopically (IR, 1H and 13C NMR, and EIMS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 1).

The four-component reactions of anilines, dialkyl acetylenedicarboxylate, acenaphthenequinone, and dimedone (or cyclohexane-1,3-dione) in acetic acid provided an efficient synthetic procedure for the functionalized spiro[acenaphthylene-1,2′-quinoline] derivatives in good yields. This reaction has the advantages of using common starting material, mild reaction conditions, and operational simplicity.

An efficient and straightforward synthetic protocol has been developed for the preparation of pyrrolo[3,4-c]coumarins via FeCl3-promoted three component reaction between substituted 2-(2-nitrovinyl)phenols, acetylenedicarboxylate and amines for the generation of a wide range of structurally interesting and pharmacologically significant compounds.

A transition-metal-free multicomponent benzannulation reaction was developed from readily available ketones, nitro-olefins, and diester acetylenedicarboxylate. This approach provides a straightforward and efficient way to construct polysubstituted benzene derivatives under mild conditions in high yields.

An efficient and facile method for the synthesis of novel spiro[indole-2,2′-pyrroles] from N-methyl-3-isatin imines, t-butyl isocyanide, and dialkyl acetylenedicarboxylate has been achieved by [3 + 2] cyclo addition reaction. All the products were purified by column chromatography as yellow solids and confirmed with 1H NMR, 13C NMR, fast atom bombardment, mass, and infrared. Compound 11 was further confirmed with x-ray analysis.

Single crystals of [Bi(ADC)2/4(ADC)3/3(H2O)2]·2H2O (P, Z = 2) and [Bi(ADC)2/4(ADC)3/3(H2O)3]·H2O (P, Z = 2) were obtained by isothermal evaporation of aqueous solutions containing acetylenedicarboxylic acid (H2ADC) and Bi(NO3)3·5H2O. Their crystal structures were solved and refined from X-ray single crystal data. They are hydrate isomers with respect to the central Bi3+ ion, which leads to completely different topologies of the resulting coordination polymers.

A new and efficient synthesis of 2-[1-alkyl-5,6-bis(alkoxycarbonyl)-1,2,3,4-tetrahydro-2-oxopyridin-3-yl]acetic acid derivatives by a one-pot three-component reaction between primary amine, dialkyl acetylenedicarboxylate, and itaconic anhydride (=3,4-dihydro-3-methylidenefuran-2,5-dione) is reported. The reaction was performed without catalyst and under solvent-free conditions with excellent yields. Notably, the ready availability of the starting materials, and the high level of practicability of the reaction and workup make this approach an attractive complementary method to access to unknown 2-[1-alkyl-5,6-bis(alkoxycarbonyl)-1,2,3,4-tetrahydro-2-oxopyridin-3-yl]acetic acid derivatives. The structures were corroborated spectroscopically (IR, 1H- and 13C-NMR, and EI-MS) and by elemental analyses. A plausible mechanism for this type of domino Michael additioncyclization reaction is proposed (Scheme 2).

A sequential one-pot two-step reaction for efficient synthesis of pyrrolo[2,1-a]isoquinoline and pyrrolo[1,2-a]quinoline derivatives in good yields has been successfully developed. The reaction included firstly Cu-catalyzed three-component reaction of isoquinoline (quinoline), acetylenedicarboxylate and alkynylbenzene and then Pd-catalyzed intramolecular C(sp)-C(sp2) coupling reaction of initially formed 1-alkenyl-2-alkynyl-1,2-dihydroisoquinoline (1,2-dihydroquinoline).

Dimethyl acetylenedicarboxylate reacts with 2 mol-equiv. B(C6F5)3 by C6F5 transfer to the central acetylenic C≡C bond with formation of a tail-to-tail coupled bis(boron ester enolate) system. The central hexasubstituted butadiene unit of this unique system reacts with dimethyl maleate in a Diels–Alder reaction to give a hydroquinone derivative.

A series of structurally diverse spirocyclic 1,3-oxazines were conveniently prepared from three-component reactions of α,β-unsaturated N-arylaldimines, dialkyl acetylenedicarboxylate and quinones in dry acetonitrile without catalyst. Various quinones including p-benzoquinone, 1,4-naphthoquinone, acenaphthenequinone, and phenanthrenequinone as well as benzil were successfully used in the reaction to give the corresponding spirocyclic 1,3-oxazines in good yields. The diastereoisomers of the obtained spirocyclic 1,3-oxazines were elucidated by 1H NMR spectra and single crystal structures.

A practical procedure for the preparation of fused 1,4-dihydropyridines was developed through the domino four-component reactions of arylamines, acetylenedicarboxylate, aromatic aldehydes, and cyclic 1,3-diketones in acetic acid. Unusual fused 1,2-dihydropyridines can also be efficiently prepared by controlling the reaction conditions.

A series of 2,3,4-trisubstituted quinoline derivatives have been synthesized by reactions between 2-aminoaryl ketones and dialkyl acetylenedicarboxylate. The synthetic pathway allows for the direct construction of said quinoline derivatives in pyridine/ethanol at ambient temperature through a zwitterion intermediate. J. Heterocyclic Chem., (2011)

Dialkyl 2-(alkylamino)-4,9-dihydro-9-oxocyclohepta[b]pyran-3,4-dicarboxylates are prepared in a one-pot three-component reaction of alkyl isocyanide, dialkyl acetylenedicarboxylate, and α-tropolone (=2-hydroxycyclohepta-2,4,6-trienone). The reaction proceeds smoothly at room temperature and under neutral conditions to afford tropolone derivatives in high yield.

An effective route to functionalized 2H-chromene (=2H-1-benzopyran) derivatives 4 is described (Scheme 1). This involves the reaction of a 1,1-diactivated alkene, resulting from the reaction of dimedone (=5,5-dimethylcyclohexane-1,3-dione; 1a) with methyl chloroglyoxylate (ClC(O)COOMe), benzyl carbonochloridate (ClC(O)OCH2Ph) or 3,5-dinitrobenzoyl chloride (3,5-(NO2)2C6H3C(O)Cl), and a dialkyl acetylenedicarboxylate (=dialkyl but-2-ynedioate) in the presence of Ph3P which undergo intramolecular Wittig reaction to produce 2H-chromene derivatives (Scheme 1).

The zwitterion, formed from the reaction of an alkyl isocyanide and a dialkyl acetylenedicarboxylate, reacts with phenacyl halides in H2O to produce γ-iminolactone derivatives in high yields. H2O helps to avoid the use of highly toxic and environmentally unfavorable solvents for this conversion.

The reaction of β-tert.- aminoacrylonitriles 1 a-1c with dimethyl acetylenedicarboxylate (DMAD) to give pyrrolizidine, indolizidine and pyrroloazepine is described.

A synthesis of quinoline derivatives is described via reaction between ethyl bromopyruvate (=ethyl 3-bromo-2-oxopropanoate), acetylenedicarboxylate, and isatin (=1H-indole-2,3-dione) in the presence of NaH as a base. Also, these reactions were performed without ethyl bromopyruvate. The reaction in the presence of ethyl bromopyruvate provides regioselectively a quinoline with the ethyl ester group in 4-position. In the absence of ethyl bromopyruvate, the reaction leads to functionalized quinolines with the same ester groups in 2-, 3-, and 4-positions.

From an aqueous solution containing ZnCO3, Tl(CH3COO), and acetylenedicarboxylic acid (H2ADC: HOOC-C≡C-COOH) single crystals of [Tl2Zn(ADC)2(H2O)2] (1) were obtained. Compound 1 crystallizes in triclinic space group P with Z = 1. A slightly distorted octahedral ZnO6 coordination and a very unsymmetric TlO6 coordination (Tl–O < 321 pm) are found, the latter probably caused by a stereochemically active lone pair at Tl+. These polyhedra are connected by the ADC2– linker to form a 3D network structure. Additionally, hydrogen bonds are formed, which involve the water molecules (O···O starting at 274 pm). These are only coordinated to Zn2+. Compound 1 is the first coordination polymer of ADC2–, which contains two different metal ions.

By slow diffusion of 4,4′-bipyridine (4,4′-bipy) into a solution of a respective metal salt and acetylenedicarboxylic acid (H2ADC), single crystals of four new coordination polymers ∞1[MII(4,4′-bipy)(H2O)4](ADC)·4H2O (MII = Mn, Fe, Co; P, Z = 1) (1–3) and ∞1[Cu(4,4′-bipy)(H2O)4](ADC)·4H2O (C2/c, Z = 4) (4) were obtained. In all compounds octahedral MII(H2O)4N2 units are connected by 4,4′-bipyridine ligands to form chain-like polymers. In 4 these octahedra are elongated due to Jahn–Teller distortion. The acetylenedicarboxylate dianions are bound by hydrogen bonds to the ∞1[MII(4,4′-bipy)2/2(H2O)4] chains to form a 3 D network. Surprisingly, the acetylenedicarboxylate dianions are not part of the first coordination sphere of the transition metal ions.

An α-oxime ester derivative prepared via treatment of an acetylenedicarboxylate or an α-keto ester with hydroxylamine underwent C-alkylation to the C=N bond of the oxime group by a Lewis-acid-promoted reaction with a trialkylzincate or a dialkylzinc reagent. The O–N bond of the thus obtained adduct was reductively cleaved under hydrogenolysis in the presence of the Pd-C catalyst to afford an α-amino ester. Treatment of the oxime derivative prepared from methyl 5-bromo-2-oxopentanoate with the trialkylzincate gave an α-alkyl proline derivative via the addition reaction followed by the intramolecular attack upon a bromine-bearing carbon. The reaction of ethyl 4-oxo-2-pentynoate with hydroxylamine formed an isoxazole derivative by way of the intramolecular attack of an in situ-generated oxime to the carbonyl group. From this isoxazole derivative, ethyl 2-amino-4-oxo-2-pentenoate was given by the Pd-C-catalyzed hydrogenolysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

A convenient one-pot four-component synthesis of tetrasubstituted pyrroles was carried out through the reaction of butane-2,3-dione with α-aminophosphorous ylides, obtained in situ from the 1 : 1 : 1 addition reaction between triphenylphosphine, dialkyl acetylenedicarboxylate, and ammonium acetate.

High hindrance Hexa tert-butoxy carbonyl dipyrrolophenanthroline and helical dihydropyrrolophen-anthroline compounds were prepared from reactions between di tert-butyl acetylenedicarboxylate and 1,10-phenanthroline in polar solvents media.

Treatment of triphenylphosphine with dialkyl acetylenedicarboxylate leads to 1:1 adduct and concomitant protonation of late adduct by pentan-2,3,4-trione 3-oxime gave the reactive intermediate, vinyltriphenylphosphonium salts, which undergoes an intramolecular Wittig reaction to produce tetrasubstituted N-hydroxypyrroles in fairly high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:100–103, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20382

The tetranuclear nickel(II) complexes [(LNi II 2 ) 2 (acetylene-dicarboxylate)][BPh4]2 (2[BPh 4 ) 2 ), [(LNi"2)2(terephthalate)]- ]-[BPh 4 ) 2 (3[BPh 4 ) 2 ), and [(LNi"2)2(isophthalate)][BPh 4 ] 2 (4[BPh 4 ] 2 ), where L 2- represents a macrocyclic hexaaza-dithiophenolate ligand, have been synthesized and characterised by UV/Vis spectroscopy, IR spectroscopy, X-ray crystallography, and magnetic susceptibility measurements. Each dicarboxylate dianion acts as a quadridentate bridging ligand linking two bioctahedral LNi 2 units via μ 1,3 -bridging carboxylate functions to generate discrete [(LNi II 2 ) 2 (dicarb-oxylate)] 2+ dications with a central LNi 2 (O 2 C-R-CO 2 )Ni 2 L core. The structures differ mainly in the distance between the center of the Ni...Ni axes of the isostructural LNi 2 units (8.841(1) A in 2[BPh 4 ) 2 , 10.712(1) in 3[BPh 4 ] 2 , and 9.561(1) in 4[BPh 4 ] 2 ) and the tilting angle between the two Ni 2 O 2 planes (86.3° in 2[BPh 4 ] 2 , 58.2° in 3[BPh 4 ] 2 , 20.9° in 4[BPh 4 ] 2 ). Magnetic susceptibility measurements on the complexes over the range 2.0-295 K reveal the presence of weak ferromagnetic exchange interactions between the Ni II ions within the dinuclear subunits with values for the magnetic exchange constant J 1 of 23.1(5), 18.1(5), and 14.2(5) cm -1 for 2[BPh 4 ] 2 , 3[BPh 4 ] 2 , and 4[BPh 4 ] 2 , respectively (H = -2JS 1 S 2 ). The magnitude of the exchange interaction J 2 across the dicarboxylate bridges is in all cases less than 0.1 cm -1 , suggesting that no significant interdimer exchange coupling occurs in 2[BPh 4 ] 2 -4[BPh 4 ] 2 .

The highly reactive 1 : 1 intermediate generated in the reaction between dialkyl acetylenedicarboxylate (=but-2-ynedioic acid dialkyl ester) 4 and triphenylphosphine was trapped by 2-amino-4-oxo-4H-1-benzopyran-3-carboxaldehydes 5 to yield highly functionalized dialkyl-1,5-dihydro-5-oxo-1-phenyl-2H-[1]benzopyrano[2,3-b]pyridine-2,3-dicarboxylates in high yield.

with MII = Fe, Co, Ni (n = 2) and MII = Cu (n = 1): Four New Coordination Polymers with Acetylenedicarboxylate (ADC2−) as Bridging Ligand By slow diffusion of pyridine (Py) into an aqueous solution of a respective metal salt and acetylenedicarboxylic acid (H2ADC) single crystals of new coordination polymers of composition (M = Fe, Co, Ni; C2/c, Z = 4) (1 – 3) and (P212121, Z = 4) (4) were obtained. In compounds 1 – 3 octahedral MIIO4N2 units are connected via acetylenedicarboxylate anions to form chain-like polymers. In compound 4 square pyramidal CuIIO3N2 units are found, which are also connected to chains by acetylenedicarboxylates. Thermoanalytical investigations on 3 show an abrupt mass loss of approx. 40 % above 130 °C, which points to a release of both pyridine ligands (calc.: 43 %). Thereafter, the sample decomposes continuously, which is confirmed by XRPD measurements, as an amorphous residue is found. Magnetic susceptibility measurements of 1 – 3 display paramagnetic behaviour in the temperature range 2-300 K. While μeff of 3 (d8 configuration) with orbital singlet ground state is nearly temperature-independent, 1 (d6) and 2 (d7) exhibit complicated μeff−T behaviour on account of a ligand-field ground state derived from the cubic states 5T2 and 4T1, respectively. On the basis of a tetragonal ligand-field model excellent adaptations are obtained with reasonable ligand-field parameters. Exchange interactions between the magnetic ions are detected in no case.

An effective route for the synthesis of phosphonate derivatives is described. This procedure involves the reaction of a trialkyl phosphites and dialkyl acetylenedicarboxylate in the presence of amines in water as the solvent at room temperature.

The K3PO4-catalyzed cascade Michael addition/alkyne carbocyclization of acetylenedicarboxylate or propargylic ester and propargylamines is developed to synthesize tri-, tetra-, and fully substituted pyrroles.

2-(Chloromethyl)-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3Н)-ones reacted with acetylenedicarboxylate ester, methyl propiolate or acetylacetylene, forming mixtures of 2-(chloromethyl)-5,6,7,10-tetrahydropyrimido[5',4':4,5]thieno[3,2-d]azocin-4(3Н)-ones and 2'-chloromethyl-6'-methylidene-2,3-dihydro-1Н-spiro[pyrido[4,5']thieno[2,3-d]pyrimidin]-4'(3'H)-ones in various ratios. Analogous products were also obtained in the reaction of 2-(methoxymethyl) derivative with methyl propiolate, while using 2-[(morpholin-4-yl)-methyl] derivative in a similar reaction led to the formation of a more complex product mixture.

A green method for the conjugate addition of indoles (I) to various nitrostyrenes (II) or acetylenedicarboxylate (IV) is developed.

The title compounds (IV) are obtained in excellent yields by three-component reaction of aniline derivatives, acetylenedicarboxylate, and aromatic aldehydes.

The title compounds (IV) are obtained by three-component reaction of various amines (II) with dialkyl acetylenedicarboxylate (I) and formaldehyde (III).

The title compounds (IV) are obtained as a single diastereomer by one-pot three-component reaction of various 1,4-dihydropyridines (I) with acetylenedicarboxylate (II), and cyclohexyl isocyanide (III) under mild reaction conditions.

The novel 1:1:1:2 addition reaction of phenacyl bromide, malononitrile, isocyanide, and acetylenedicarboxylate provides the polycyclic product (V) as the only one of 16 possible diastereomers.