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Efforts to generate organomanganese reagents under ball-milling conditions have led to the serendipitous discovery that manganese metal can mediate the reductive dimerization of arylidene malonates. The newly uncovered process has been optimized and its mechanism explored using CV measurements, radical trapping experiments, EPR spectroscopy, and solution control reactions. This unique reactivity can also be translated to solution whereupon pre-milling of the manganese is required.

A highly environmentally friendly procedure was developed for the Knoevenagel condensation of aromatic aldehydes with diethyl malonate in the presence of FeCl3 and N-fluorobenzenesulfonimide as a source of electrophilic fluorine under solvent-free conditions. The scope of the reaction was explored using commercially available substrates. The reaction with substituted salicylaldehydes afforded the corresponding coumarin derivatives which attract interest due to their potential medicinal importance.

An unprecedented direct C-C coupling reaction of unprotected primary amines with active methylene compounds is reported. The reaction involves a biomimetic deamination of amines which was achieved under conditions free of metallic reagents and strong oxidizing agents. A wide range of primary amines was reacted with different active methylene compounds to provide structurally diverse trisubstituted alkenes and dihydropyridines. A kinetic study revealed an activation barrier of 10.1 kcal mol-1 for the conversion of a key intermediate of the reaction.

We report an acridium-based organic photocatalyst as an efficient replacement for iridium-based photocatalysts to oxidise boronic acid derivatives by a single electron process. Furthermore, we applied the developed catalytic system to the synthesis of four active pharmaceutical ingredients (APIs). A straightforward scale up approach using continuous flow photoreactors is also reported affording gram an hour throughput.

We have explored here the scope of the age-old diethyl malonate-based accesses to α-amino esters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered. The synthetic modifications of some of the intermediates - using Suzuki-Miyaura coupling or cycloadditions - before undertaking the oximation step - provided accesses to further α-amino esters. Moreover, other pathways to α-hydroxyimino esters were explored including an attempt to improve the cycloadditions between ethyl β-bromo-α-hydroxyiminocarboxylate and various alkylfuranes.

Here, we report a convenient access to diastereoselective synthesis of polysubstituted pyrrolidines bearing a unique spiro quaternary center at the C-2 position and another quaternary center at C-4. The synthesis system, CuII/P, N-Ligand-cataly

The synthesis of various electron-deficient 1,1-dicarbonyl ester 1,3-dienes substituted in position 2 or 3 of the diene moiety has been developed. Georg Thieme Verlag Stuttgart. New York.

A series of 6-oxo-1,4,5,6-tetrahydropyrimidine-5-carboxylate derivatives were prepared to evaluate their ability of inhibiting neuraminidase (NA) of influenza A virus. All the compounds were synthesized in good yields starting from aldehyde by using a suitable synthetic strategy, which showed moderate inhibitory activity against influenza A NA. Compound 6g exhibited the strongest inhibitory activity against influenza virus A NA (IC50 = 17.64 μM), which indicated pyrimidine ring could be used as a core structure to design novel influenza NA inhibitors.

We have succeeded in the visible light-mediated synthetic use of α-aminoalkyl radicals derived from α-silyl secondary amines toward addition to α,β-unsaturated carbonyl compounds. The resulting γ-aminocarbonyl compounds are converted into γ-lactams and pyrroles in a one-pot process. This journal is the Partner Organisations 2014.

Heterogeneous catalysts of different nature can be combined in one-pot tandem reactions, but the compatibility issues of catalysts with reagents, products, and by-products make more convenient the application of a sequential procedure, in which the catalyst is filtered after each reaction and the crude is used in the following reaction without purification. In this way the recovery and reuse of each catalyst can be optimized to obtain the maximum productivity. The nature of the reactions, and the catalysts involved in them, conditions the maximum number of successive steps in the sequence. In the case of the (Knoevenagel + Mukaiyama-Michael + hydrogenation + transesterification) process tested in this work, the optimal results are obtained when the sequential method is applied to only three reactions, whereas the four reactions sequence shows limitations in the yield of the last transesterification step. The Royal Society of Chemistry 2013.

The Knoevenagel condensation between an active methylene compound and an aromatic aldehyde with a carbamic acid ammonium salt used as an organocatalyst gave the desired Knoevenagel products in up to 98% yield. The reaction occurred at rt and in a short reaction time under solvent-free conditions. In addition, no extraction, wash, or chromatography steps were needed to obtain a high-purity Knoevenagel product.

An additive-free and highly diastereoselective Michael addition reaction of an N-tert-butanesulfinyl imidate to α,β-unsaturated diesters has been developed using LDA as a base with good to excellent yields. The utility of this chemistry is further demonstrated by the asymmetric synthesis of 3-substituted indanone derivatives 8a, 8d, 8e, and 8i with high enantiomeric excess, which are potential building blocks for preparing biologically active lead compounds.

Polycarbosilane (PCS) was synthesized by the polycondensation of trichloromethylsilane and trimethoxyvinylsilane in the presence of sodium metal. PCS has a highly crosslinked structure, high ceramic yield and high surface area. Titanium metal ion was attached to the polycarbosilane and its catalytic activity was investigated. The Knoevenagel condensation reaction catalysed by titanium-incorporated polycarbosilane is reported. The titanium-incorporated PCS catalysed the reaction well and with a diverse set of substrates the reaction proceeded with good yield. PCS-supported transition metal catalysts have been prepared for the first time and used successfully in the Knoevenagel condensation reaction. Copyright

A series of 69 polar olefins with various typical structures (X) were synthesized and the thermodynamic affinities (defined in terms of the molar enthalpy changes or the standard redox potentials in this work) of the polar olefins obtaining hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the polar olefins (X ?-) obtaining protons and hydrogen atoms, and the thermodynamic affinities of the hydrogen adducts of the polar olefins (XH?) obtaining electrons in acetonitrile were determined using titration calorimetry and electrochemical methods. The pure Ci - 'C π-bond heterolytic and homolytic dissociation energies of the polar olefins (X) in acetonitrile and the pure Ci - 'C π-bond homolytic dissociation energies of the radical anions of the polar olefins (X?-) in acetonitrile were estimated. The remote substituent effects on the six thermodynamic affinities of the polar olefins and their related reaction intermediates were examined using the Hammett linear free-energy relationships; the results show that the Hammett linear free-energy relationships all hold in the six chemical and electrochemical processes. The information disclosed in this work could not only supply a gap of the chemical thermodynamics of olefins as one class of very important organic unsaturated compounds but also strongly promote the fast development of the chemistry and applications of olefins.

Chiral N,N′-dioxide/Zn(NTf2)2 complexes were demonstrated to be highly effective in the direct asymmetric conjugate addition of arylacetonitriles to alkylidene malonates under mild conditions. A wide range of substrates were tolerated to afford their corresponding products in moderate-to-good yields with high diastereoselectivities (82:18->99:1 d.r.) and enantioselectivities (81-99 % ee). The reactions performed well, owing to the high Lewis acidity of the metal triflimidate and a ligand-acceleration effect. The N,N′-dioxide also benefited the deprotonation process as a Bronsted base. The catalytic reaction could be performed on the gram-scale with retention of yield, diastereoselectivity, and enantioselectivity. The products that contained functional groups were ready for further manipulation. In addition, a possible catalytic model was proposed to explain the origin of the asymmetric induction. Copyright

Solution phase multi-component synthetic strategy was utilized to synthesize trisubstituted pyrrolizidines. The key step was the ring-forming 1,3-dipolar cycloaddition of non-stabilized azomethine ylides generated in situ with electron-deficient dipolarop

The titled new functionalized ligand 2-[(4-chloro-phenyl)-pyrrolidin-1-yl- methyl]-malonic acid diethyl ester (4) is prepared in good yield through condensation of pyrazole and 3,5-dimethyl-pyrazole, respectively, with 2-arylidene-malonic acid diethyl est

During studies on exploiting the catalytic promiscuity of crude porcine pancreas lipase (PPL) in ionic liquid for C=C bond formations, bovine serum albumin (BSA) was found to be competing for these reactions. After a detailed investigation, we establish that these transformations are possible by unspecific protein catalysis rather than catalytic promiscuity of "PPL" - a first insight into the role of protein impurities in crude enzyme. Thus, a novel and highly efficient, environmentally friendly approach involving synergistic catalysis by bovine serum albumin-1-butyl-3- methylimidazolium bromide (BSA-[bmim]Br) has been developed for the synthesis of (E)-α,β-unsaturated compounds including a one-pot cascade synthesis of cinnamic acids and coumarins via aldol, Knoevenagel and Knoevenagel-Doebner condensations.

A series of ethyl 3-aryl-4-oxo-3,3a,4,6-tetrahydro-1H-furo[3,4-c]pyran-3a- carboxylates were prepared through the metal-catalyzed domino reaction of alkylidene malonates and 1,4-butynediol under a one-pot reaction condition at room temperature. Their in vitro anti-proliferative activities were subsequently evaluated in A549, QGY and HeLa cells. The majority of the compounds showed potent anti-tumor activity against HeLa cells. In particular, compound 3l was the most potent compound with IC50 value of 5.4 μM. For the first time, the X-ray structure of the anti-tumor ethyl 3-aryl-4-oxo-3,3a,4,6- tetrahydro-1H-furo[3,4-c]pyran-3a-carboxylates is determined.

"Chemical Equation Presented" Asymmetric cyanation of a class of easily available olefins with a favorable cyanide source ethyl cyanoformate (CNCOOEt) was realized by an interesting modular catalyst. High yields and ee values were obtained for a range of substrates under solvent-free and mild reaction conditions. The products obtained could be easily transformed to the enantioenriched useful intermediates 5,6, and pharmaceutically Important γ-aminobutyric acid 7.

β-Amino dicarbonyl compounds comprise a class of useful ligands on the coordination chemistry. In view of their importance, an effcient and facile method for the synthesis of β-amino dicarbonyl compounds has been developed, exploring the aza-Michael addition reactions in an aqueous medium. It was possible to achieve good to excellent yields, along with regioselectivity, the substituted diethyl 2-(phenylmethyl)malonates that were easily isolated without any chromatographic purifcation. The correct confguration of two of these β-amino dicarbonyl compounds were confrmed by X-ray crystallography. A complementary mechanism of this aza-Michael protocol is proposed to explain the results obtained.

1-Ethyl-3-methylimidazolium bromide was used as a green recyclable alternative to volatile organic solvents for KOH catalyzed three-component synthesis of diethyl alkylsulfanylmethylmalonates from aldehydes, diethyl malonate, and alkylthiols. Graphical Abstract: A synthesis of diethyl alkylsulfanylmethylmalonates catalyzed by KOH in an ionic liquid [Figure not available: see fulltext.]

LiClO4 is used as catalyst for direct Mannich-type reaction of aryl aldehydes, aryl amines, and diethyl malonic ester under solvent-free conditions. This three-component reaction afforded the corresponding β-amino esters in good yields with simple and env

Three hydroxyl functionalized zwitterionic liquids (ZILs) were found to be novel recyclable catalysts for the Knoevenagel condensation between aldehydes or ketones and active methylene compounds in aqueous medium. Both aldehydes and ketones gave satisfactory results. The products could simply be separated from the catalysts/water, and the catalysts could be recycled six times without noticeably decreasing the catalytic activity.

A novel efficient and eco-friendly nanocrystalline ZnO catalyst was used for the Knoevenagel condensation and for the reduction of C=C double bonds at room temperature in the absence of solvents.

Various kinds of 3-substituted (E)-2-(hydroxymethyl)prop-2-enyl acetates were conveniently obtained in excellent yields by the regiospecific acetylation of 2-alkylidenepropane-1,3-diols with 10 equivalents of vinyl acetate in the presence of 50% w/w porcine pancreatic lipase (PPL) type II; the starting materials or (Z)-monoacetate or diacetate byproducts were generally not present. Georg Thieme Verlag Stuttgart.

(Chemical Equation Presented) Choosing a suitable hydride reducing agent and thermodynamic analysis of reduction mechanisms is facilitated by experimental hydride affinities ΔHH-A, which are reported herein for 28 polarized olefins 1 in acetonitrile (see scheme). The method should also be applicable to ketones, aldehydes, and imines.

Knoevenagel condensation of aromatic aldehydes with active methylene compounds under solvent-free conditions to synthesize arylidene compounds in good to excellent yields using powdered anhydrous K2CO3 and PEG400 as catalysts has bee

The moisture and air stable ionic liquids 1-butyl-3-methylimidazonium tetrafluoroborate [bmim]BF4 and 1-butyl-3-methylimidazonium hexafluorophosphate [bmim]PF6 were used as 'green' recycle alternatives to volatile organic solvents (VOCs) for ethylenediammonium diacetate (EDDA) catalyzed Knoevenagel condensation between aldehydes or ketones with active methylene compounds. Both aldehydes and ketones gave satisfactory results. The ionic liquids containing catalyst EDDA were recycled several times with no decrease in yields and reaction rates. In the case of 2-hydroxybenzaldehyde, the reactions led to the formation of 3-substituted coumarins under standard reaction conditions.

An environmentally benign, solventless, rapid and economic technique for the synthesis of substituted quinolines, indoles and aromatic compounds using Knoevenagel condensation is described from readily available aromatic and heterocyclic aldehydes and die

The present invention relates to ion channel modulating agents. More particularly, the present invention relates to a particular class of chemical compounds that has proven useful as modulators of SK Ca, IK Ca and BK Ca channels. In further aspects, the present invention relates to the use of these SK/IK/BK channel modulating agents for the manufacture of medicaments, for methods of therapy, and pharmaceutical compositions comprising the SK/IK/BK channel modulating agents. The SK/IK/BK channel modulating agents of the invention are useful for the treatment or alleviation of diseases and conditions associated with the SK/IK/BK channels.

Diethyl malonate undergoes condensation with aromatic aldehydes without solvents, in the presence of a Mexican bentonite using infrared irradiations as the energy source, to give the benzylidenemalonate compounds in fair yield.

Diethyl and dimethyl malonate react selectively with aldehydes to afford alkenes within a few minutes, by adsorption on acidic clay (Montmorillonite K10) in a solvent-free reaction under microwave irradiation in a domestic oven.

α,β-Unsaturated malonic esters are conveniently synthesized from the reaction of dibromomalonate with carbonyl compounds promoted by dibutyl telluride in excellent yields. A possible mechanism involving twice halophilic attacks of dibutyl telluride is proposed. This methodology provides a facile route to α,β-unsaturated malonic esters and represents an alternative to the Knoevenagel reaction.

A series of 5-spirocyclopropanobarbiturates bearing alkyl and aryl substituents on the cyclopropane ring has been synthesized.Dihydro-orotate dehydrogenase from Clostridium oroticum was shown to be inhibited by these compounds.A related series of 5-member

A convenient synthesis of α,β-unsaturated esters (in 68-96percent yields) from the reaction of a bromomalonic ester with aldehydes promoted by tri-n-butylarsine is descriebed.A mechanism involving halophilic attack of tri-n-butylarsine leading to the formation of a salt followed by reaction with carbonyl compounds is proposed.This methodology provides a convenient route to α,β-unsaturated esters and represents an alternative to the Knoevenagel reaction.