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Total synthesis of actinophenanthroline A, a marine actinomycete within the family of Streptomycetaceae (strain CNQ-149) is reported. Both the racemic and enantiopure actinophenanthroline A have been synthesized with good overall yields. Highlight of the synthesis contains the classical and economical double Doebner–Miller reaction to access the 1,7-phenanthroline core followed by a modified EDCI coupling.

Now within reach: In the remote C-H arylation of alicyclic amines the key step is the transannular coordination of the palladium catalyst (see picture, DG=directing group). This strategy is convenient for the late-stage functionalization of complex bioactive molecules in order to probe structure-activity relationships.

An enantioselective intramolecular oxa-Michael reaction of enols catalyzed by a squaramide-containing tertiary amine based bifunctional organocatalyst, which efficiently activates the o-homoformyl chalcones, provides chiral isochromenes in moderate yields and good to excellent enantioselectivities.

The synthesis of hitherto unreported S-alkyl/aryl benzothiazole-2-carbothioate is reported from thiols, oxalyl chloride, and 2-aminothiophenols using 10 mol % n-tetrabutylammonium iodide (TBAI) as catalyst in acetonitrile through multicomponent reaction (MCR) strategy. The present protocol favored formation of benzothiazoles and thioesters via simultaneous formation of C–N and C–S bonds in good yields with a wide range of substrates. A few of the synthesized derivatives were evaluated for their antimicrobial activity against the protozoan parasite Leishmania donovani, a causative agent of visceral leishmaniasis (VL). Further, these compounds displayed no toxicity toward macrophage RAW 264.7 cells and are therefore nontoxic and effective antileishmanial leads. In silico docking studies were performed to understand the possible binding site interaction with trypanothione reductase (TryR).

Antiferromagnetic (AFM) materials were not well respected from practical point of view until the discovery of interlayer exchange coupling in 1986 and giant magnetoresistance (GMR) in 1988–1989. Soon after, the old discovery (namely exchange anisotropy in 1956) and surface antiferromagnetism find their practical importance in magnetic recording, storage and sensor devices. However, the progress is partly hindered by limited experimental techniques to study surface AFM properties. This paper reviews recent experimental advances in the field of surface antiferromagnetism of prototype AFM oxide NiO(100), particularly using laterally resolved magnetic spectroscopy. Studies performed on bare NiO(100) single crystal and thin films using photoemission electron microscopy (PEEM) with X-ray magnetic linear dichroism (XMLD) as contrast mechanism and using a recently proposed approach utilizing the capability of a low energy electron microscope (LEEM), namely AFM-LEEM, are highlighted. We expect that AFM-LEEM in combination with XMLD-PEEM will soon explore more finer aspects AFM materials.

A mild and greener protocol was developed to synthesize substituted quinazolinones and dihydroquinazolinones via deep eutectic solvent (DES) mediated cyclization with a series of aliphatic, aromatic, and heteroaromatic aldehydes in good to excellent yields. This greener strategy was further utilised to synthesize various quinazolinone natural products and drugs.

An efficient, simple, environmentally benign synthetic protocol is developed for synthesis of biologically and medicinally relevant pyrazole coupled imidazo[1,2-a]pyridine derivatives via three component reaction of alkyl-4-formyl-1-phenyl-1H-pyrazole-3-carboxylate, 2-aminopyridine and isocyanide in the presence of nano-crystalline ZnO in ethanol through one pot chemical operation. The present synthetic protocol provides several advantages like operational simplicity, short reaction time, reusable catalyst, and easy work-up procedure.

First in situ generation of a betaine intermediate has been developed using two new precursors oxobis(methylthio)ketene acetals and N-butyl-N'-methyl ethane-1,2-diamine for the synthesis of annulated dihydrofurans. This protocol adds a new dimension for the formation of annulated dihydrofurans through a series of selective consecutive formation of C-C and C-O bonds after reacting with enone rings. This in situ generated betaine intermediate corresponds to deoxy-Breslow intermediates in the reaction via elimination of NHC.

Amino acid dl -threonine derived ionic liquid was treated with salicylaldehyde to give corresponding Schiff base which subsequently is complexed with iron and used as a green catalyst for aerobic oxidation of amines under solvent-less conditions. The developed catalyst was readily synthesized, reusable, and exhibited superior catalytic activity owing to the synergistic effect of ionic liquid moiety. The developed catalyst was found to be quite stable and could be reused for several runs without any significant loss in catalytic activity.

A copper-incorporated mesoporous silica catalyst was synthesized and characterized by N2 adsorption analysis, HRTEM, EDX-elemental analysis, and XRD studies. The silica material possesses mesopores of dimension 3–5 nm. Incorporation of copper within the silica network produces enhanced surface acidity in comparison to pure silica, which is reflected in the sonication-assisted rapid reaction between dimedone, formaldehyde, and amines. Sonication-mediated room temperature synthesis was proved to be more convenient and rapid than ordinary stirring. A standard leaching experiment proved that the reaction was heterogeneous with this recyclable catalyst.

A facile method has been developed for the preparation of novel heterocyclic compounds by the reaction of 3-formylchromones, benzylamines, and 2-aminophenols with 3-oxobutanoates. 3-Oxobutanoates bearing trifluoro or trichloro substituents and trifluoro containing 1,3-diketones facilitated the reaction. The reaction proceeds via a Schiff base mediated Michael addition followed by the selective addition of enamine to the carbonyl group adjacent to the trihalo group due to a strong electron withdrawing effect. The present three-component, one-pot protocol provided heterocyclic compounds without a catalyst.

A concise synthetic approach to a class of biologically interesting cyclic tetrapeptides is reported which involves a late-stage functionalization of a macrocyclic scaffold through cross metathesis in an attempt to create diversity. The utility of this protocol is demonstrated through the preparation of three structural analogues of the important naturally occurring histone deacetylase inhibitor FR-225497.

The asymmetric synthesis of two naturally occurring 5-hydroxy-γ-butyrolactones, (4R,5R)-5-hydroxy-4-decanolide (1a) and (−)-muricatacin (2), is described using a general alkyne-mediated strategy. The key steps involved are Sonogashira coupling for the desired carbon-chain extension followed by Sharpless asymmetric dihydroxylation to construct the hydroxy-lactone framework.

Substituted 1H-benzimidazoles, pyrazolones, and pyrazoles have been synthesized by the condensation of ortho-phenylenediamines and phenylhydrazines, respectively, with ethyl 4-chloro-3-oxobutanoate in good yields. The present approach is novel, straightforward, and being reported for the first time with ethyl 4-chloro-3-oxobutanoate.

The heterogeneous title reaction exhibits superior activity compared to homogeneous cobalt phthalocyanine catalysts with added benefits of easy recovery and recycling.

It is demonstrated for the first time that aromatic aldehydes can be directly formylated with CO2 as C1 carbon source under base free conditions.

This mini-review summarizes the latest accomplishments with group 6 metal alkylidene-N-heterocyclic carbene complexes (metal = Mo, W) for use in olefin metathesis. Both the fundamentals and the unique features of this novel class of olefin metathesis catalysts are presented. Also, their use and performance in ring-closing metathesis, cross metathesis, homometathesis, and self-metathesis reactions as well as in ring-opening metathesis polymerization and cyclopolymerization is outlined.

Using tBuOK in stoichiometric as well as catalytic amounts and with slight modifications (temperature, solvent), a variety of benzyl and cinnamyl azides can be transformed into the corresponding homoallylic amines.

Naphthyridines (III) are simply, highly atom-economically, and environmentally friendly synthesized in high yields using ZnTiO3 as catalyst.

Three classes of densely functionalized dispirocyclopentaneoxindoles containing multiple stereocenters are synthesized via base-promoted domino- and self-domino reactions.

The required alkyl or aryl α-azidoperoxide substrates may be prepared in situ starting from the corresponding aldehydes, thus offering a convenient one-pot two-step approach to tertiary alkylesters.

The three component reaction of isatins, chromenone (III), and malononitrile in methanol affords the title compounds (IV).

A cationic ruthenium(II)-complex was utilized in the efficient synthesis of phthalimide derivatives by CH activation with synthetically useful amides. The reaction proceeded through a mechanistically unique insertion of a cycloruthenated species into a CHet multiple bond of isocyanate. The novel method also proved applicable for the synthesis of heteroaromatic unsymmetric diamides as well as a potent COX-2 enzyme inhibitor.

The dihydroquinoline derivatives are more fluorescent than the corresponding quinoline derivatives.

A wide range of trisubstituted thiazoles is obtained by a clean and efficient three-component domino reaction of arylglyoxals, cyclic 1,3-dicarbonyl compounds and thioamides in H2O.

A number of alpha-cyano-beta-substituted ethyl propenoates were synthesised by condensation of appropriate aldehydes with ethyl cyanoacetate in basic medium. These compounds have been studied for their antileishmanial activities in vivo in hamsters. Two compounds exhibited 70-77% activities both by intramuscular and oral routes.

A facile and versatile catalyst-free method for the preparation of a wide range of pentasubstituted pyrroles has been reported using four-component reactions of arylglyoxal monohydrate, β-keto esters, amines, and various cyclic 1,3-dicarbonyls under mild reaction conditions. Employing this methodology, pseudo seven-component reactions have also been achieved in the case of p-phenylenediamine to provide conjugated bispyrroles with arene spacers.

A Lewis acid catalyzed domino reaction cascades through azide–alkene cycloaddition, rearrangement, aziridine ring opening, and azomethine cycloaddition with a parent dipolarophile, resulting in 3,3′-pyrrolidinyldispirooxindoles containing four contiguous chiral stereocenters with two contiguous quaternary spirostereocenters.

A convergent and stereoselective total synthesis of decarestrictine I, a polyketide natural product, is described. Both acid and alcohol fragments were prepared from the readily available L-malic acid via StillGennari olefination and Sharpless asymmetric epoxidation. The Steglich esterification and ring-closing metathesis (RCM) are employed to combine both acid and alcohol fragments.

A series of 2H-benzo[g]pyrazolo[3,4-b]quinoline-5,10(4H,11H)-dione derivatives has been synthesized from the three component reactions of 2-hydroxy-1,4-naphthoquinone, aldehydes, and aminopyrazoles in the presence of a catalytic amount of L-proline. This domino reaction proceeds smoothly in good to excellent yields and offers several advantages including no column chromatography, a simple reaction procedure, metal-free reaction conditions and being applicable to a broad range of aldehydes.

A novel palladium-catalyzed reaction involving an unusual nucleophilic attack on a palladium enolate was developed using a spiro-bis(isoxazoline) (SPRIX) ligand. Treatment of alkynyl cyclohexadienone substrates with a Pd/SPRIX catalyst in acetic acid under an oxygen atmosphere furnished diacetoxylated benzofuranone derivatives in good yields. This cyclative diacetoxylation proceeded enantioselectively in the presence of an optically pure SPRIX ligand.

Azidocarbenium ions, which are formed in the presence of a lewis acid from gem-diazides, have been trapped by nucleophiles for the first time.

The multicomponent reaction of malononitrile, aldehyde and a third reaction partner such as naphthol/4-hydroxycoumarine/2-hydroxynaphthoquinone/kojic acid/enolizable ketone or thiol in the presence of imidazole as an organocatalyst provides very interesting molecular diversity. In an almost neutral reaction medium, this protocol provides easy access to highly functionalized 2-amino-4H-chromenes, dienes and 2-amino pyridines using in situ-generated aryl/alkylylidenemalononitrile derivatives obtained from the reaction of aldehydes and malononitrile along with various nucleophiles under reflux conditions in ethanol. This methodology is useful for the easy access of a wide range of structurally diverse functionalized molecules having potential application in biological systems.

The present Letter describes the use of magnetically separable palladium–graphene nanocomposite, a complete magnetically separable catalyst for the synthesis of 2-alkyl quinolines via reaction of anilines with alkenyl ethers. Because of the uniform decoration of the Pd nanoparticles on support, the catalyst exhibited higher catalytic efficiency and it remains unaltered even after six repeated cycles.

The presence of electron-withdrawing groups on the chloroquinoline-3-carbaldehyde moiety provides inseparable mixtures of the corresponding products in low yields.

Photoreduction of CO2 to MeOH is carried out using 20 W white cold LED flood light in DMF/H2O or MeCN/H2O solutions containing NEt3 as a reductive quencher and the [Mo6Br8iBr6a] 2- (i: inner; a: apical) cluster as photocatalyst.

The stereoselective total synthesis of (I) is achieved via two alternative strategies involving either a Prins cyclization as the key step (28% overall yield) or a 1,3-syn reduction of a β-hydroxy ketone (30% overall yield).

The highly ortho-selective mononitration of phenols is achieved in short reaction times using urea nitrate as a safe nitrating agent under microwave irradiation.

Most of the synthesized title compounds (III) (19 examples) are found to be active against intracellular amastigote form of Leishmania donovani.

The approach to 3H-pyrroles presented herein offers an unprecedented coupling which leads to the construction of the nitrogen containing ring without starting from any amine moiety.

A novel route to synthesize the biologically active benzimidazolopyrazine core is outlined. The reaction proceeds via tandem benzimidazole formation/annulations of indole, pyrrole and aliphatic δ-alkynyl aldehydes in the presence of copper salts and green solvents with moderate to good yields.

A simple, efficient and environmentally benign approach for the synthesis of non-symmetrical dialkyl carbonates (III) (18 examples) via ionic liquid promoted transesterification of dimethyl carbonate is developed.