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One-pot synthesis of α-methyl ketones starting from 1,3-diaryl propenols or 1-aryl propenols and methanol as a C1 source is demonstrated. This one-pot isomerization-methylation is catalyzed by commercially available Pd(OAc)2 with H2O as the only by-product. Mechanistic studies and deuterium labelling experiments indicate the involvement of isomerization of allyl alcohol followed by methylation through a hydrogen-borrowing pathway in these isomerization-methylation reactions.

Earth abundant metals are much less expensive, promising, valuable metals and could be served as catalysts for the borrowing hydrogen reaction, dehydrogenation and heterocycles synthesis, instead of noble metals. The uniformly dispersed zinc composites were designed, synthesized and carefully characterized by means of XPS, EDS, TEM and XRD. The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines, ketones with alcohols in water under base-free conditions, while unsaturated carbonyl compounds could also be synthesized by tuning the reaction conditions. Importantly, it was the first time to realize the synthesis of 2-aryl-1H-benzo[d]imidazole derivatives by using this zinc composite under green conditions. Meanwhile, this zinc catalyst could be easily recovered and reused for at least five times.

Cancer is the second death cause worldwide, with breast and colon cancer among the most prevalent types. Traditional treatment strategies have several side effects that inspire the development of novel anticancer agents derived from natural sources, like chalcone derivatives. For this investigation, twenty-three chalcones (4a-w) were synthesized and evaluated as antiproliferative agents against MCF-7 and Caco-2 cells, finding three and two compounds with similar or higher antiproliferative activity than daunorubicin, while only two chalcones showed better selectivity indexes than daunorubicin on MCF-7. From these results, we developed good-performance QSAR models (r > 0.850, q2>0.650), finding several structural features that could modify chalcone activity and selectivity. According to these models, chalcones 4w and 4t have high potency and selectivity against Caco-2 and MCF-7, respectively, which make them attractive candidates for hit-to-lead development of ROS-independent pro apoptotic agents.

The umpolung Michael addition of isatin N,N′-cyclic azomethine imine 1,3-dipoles with chalcones is reported. The reaction could be finished within a very short time (0.3-2 min), with 3,3-disubstituted oxindole derivatives obtained in moderate to excellent yields with promising dr values. Unusual Michael adducts were obtained in moderate to high yields (26-98%) with low to high diastereoselectivities (0.8: 1 to 8.5: 1 dr). All the synthesized compounds (3, 3′, 4, 5, 5′, 7, 7′, 9 and 9′) were well characterized by FTIR, NMR, and mass spectral analyses and further confirmed by the single-crystal X-ray diffraction analysis of compounds 3aa and 4n.

Under the condition of air, the water-soluble inorganic weak base is used as a catalyst to catalyze the hydrogen transfer reaction of the propargyl alcohol compound, so that the green synthesis of the high-trans selective chalcone compound is realized. Reaction temperature: 80 - 120 °C and reaction time 12 - 48 hours. To the technical scheme, any transition metal catalyst and ligand do not need to be used, inert gas protection is not needed, no other byproducts are generated, the atom economy 100%, green and environment friendliness are avoided, and the product is a high-selectivity (E)-type product. The reaction conditions are relatively low in requirement. Compared with the prior art, the alkali catalyst is obvious in advantages, and has a certain application prospect in the fields of organic synthesis, biochemistry, medicine and the like.

Several simple, fast and practical protocols have been developed to synthesize internal or terminal propargylamines and chalcones via A3-coupling reaction of aldehydes, amines, and alkynes catalyzed by an easily available catalyst Ag2CO3 under solvent-free condition. The reaction proceeded smoothly to deliver various products in good-to-excellent yields with good functional group tolerance. Gram-scale preparation, bioactive molecule synthesis and asymmetric substrates have been demonstrated. Furthermore, plausible mechanisms for the synthesis of different products have been proposed.

High active ligand usually plays an important role during catalysis and synthesis chemistry. A new and efficient benzotriazole-pyridinyl-silane ligand (BPS) was designed, and the corresponding iridium and copper catalysts were synthesized and thoroughly characterized by means of EDS, TEM, and XPS. The resulting iridium composite revealed excellent catalytic activity for the reaction of tert-butanesulfinamide with benzyl alcohols, while copper catalyst could realize the synthesis of unsaturated carbonyl compounds through the reaction of benzyl alcohols with ketones. This provided an efficient method for selective synthesis of unsaturated carbonyl compounds from benzyl alcohols and ketones in high yields with good recovery performance.

An olefinic difunctionalization method of enones was presented hereviaaerobic visible-light catalysis. A novel reactivity was showcased in conjunction with the selective Csp2-C(CO) bond activation of enones, which provided a convenient method for the preparation of various β-thiolated-α-functionalized compounds. Moreover, the preliminary investigation of the mechanism indicated that a β-peroxysulfide intermediate was formed under the promotion of visible light under an oxygen atmosphere, which finally induced the unexpected C-C bond cleavage.

A series of the chalcone derivatives of the five-membered monoheterocyclic compounds, (E)-1-aryl-3-heteroarylpropen-1-ones, were prepared by aldol condensation of the corresponding aldehydes of thiophene, pyrrole, and furan with m- and p-substituted acetophenones. Similar condensation of the acetyl compounds of the heterocycles with m- and p-substituted benzaldehydes gave another series of the chalcone derivatives, (E)-1-heteroaryl-3-arylpropen-1-ones. The 13C chemical shift values (δC) of the chalcone derivatives were determined in order to find if they correlated with the Hammett σ values. A good correlation, especially for the β-C for both series, was found for the 13C chemical shift values (δC) of the chalcone derivatives with the Hammett σ values. The chemical shift values of the β-C of the heterocyclic compounds were plotted against those of the benzene derivatives. The resulting slopes were found to be close to the values of the aromaticity indices.

A reverse hydrogenolysis process has been developed for two-site coupling of 2-hydroxy-1,4-naphthoquinones with olefins to produce naphtha[2,3-b]furan-4,9-diones and hydrogen (H2). The reaction is catalyzed by commercially available Pd/C without oxidants and hydrogen acceptors, thereby providing an intrinsically waste-free approach for the synthesis of functionalized and potentially biologically relevant naphtha[2,3-b]furan-4,9-diones.

A sustainable, chemoselective 1,4-reduction of α,β-unsaturated ketones by means of an electrochemical method is presented, wherein the extremely inexpensive ammonium chloride (NH4Cl) is applied as the only additive. The reaction proceeds smoothly in the air at ambient temperature. Mechanistic studies reveal that both NH4Cl and solvent methanol work as hydrogen donors.

A facile and efficient synthesis of 1H-indazoles and 1H-pyrazoles through a copper-promoted oxidative intramolecular C–H amination of hydrazones using a cleavable directing group was developed. This reaction is characterized by its mild conditions, operational simplicity, readily available reagents, and excellent yields. A tentative mechanism for Cu-mediated C–H oxidative amination was proposed.

1-Arylvinyl formates as a kind of new CO surrogate have been explored for the first time. Most of the known CO precursors usually produce undesired residuals, which have to be removed. In this strategy, after CO release, the in situ generated acetophenones from 1-arylvinyl formates can be successfully applied as a good ketone source in the synthesis of chalcones with benzaldehydes via a palladium-catalyzed reductive carbonylation reaction. A variety of chalcones were isolated in satisfactory to good yields with good substrates compatibilities under mild conditions.

Chalcones are a group of molecules with a broad spectrum of biological activities, being especially appealing for their antiproliferative effects on several cancer cell lines. For this reason, we synthesized 23 chalcones with good to excellent yields and assessed their effect on the viability of the SH-SY5Y neuroblastoma cell line and on primary human fibroblasts. The results indicated that 18 of these compounds were more active than 5-fluorouracil in the cancer cell line and one of them was more selective than this reference drug. To identify structural features related to the antiproliferative activity of these compounds, as well as, the selectivity on the cancer cell line, a 2D-QSAR analysis was performed. The QSAR model (q2 = 0.803; r2 = 0.836) showed that lipophilicity (CLogP) is the most important factor to increase their cytotoxicity on the cancer cell line. On the other hand, the selectivity QSAR model (q2 = 0.917; r2 = 0.916) showed that changes in the Mulliken’s charge of the carbonyl group and at the C4’ position in the chalcone core can increase the selectivity for SH-SY5Y cell line compared to normal fibroblasts.

A practical and highly enantioselective nonenzymatic kinetic resolution of racemic β-hydroxy carbonyl (aldol) compounds through enantioselective dehydration process was developed using a cation-binding Song's oligoethylene glycol (oligoEG) catalyst with p

A novel metal-free reduction system, in which H2Se (or HSe-) produced in situ from Se/DMF/H2O acts as the active reducing species, has been developed. By using water as an inexpensive, safe, and environmentally friendly surrogate as the hydrogen donor, this new reduction system incorporating Se/DMF/H2O displayed high selectivity and good activity in the reduction of α,β-unsaturated ketones and alkynes. Therefore, this reduction system has great potential to be a general and practical reduction methodology in organic transformation.

A synthetic method for [alpha],[beta]-unsaturated ketone is a method which catalyzes a primary alconol and a secondary alcohol to oxidize and couple by a supported catalyst. The method includes the steps of adding the primary alconol, the secondary alcohol, an alkali and the catalyst into the mixed solvent mixing water and tert-butyl alcohol; stirring at 0-100 DEG C for 0.5-36 hours under the existence of an oxidizing agent. The yield of [alpha],[beta]-unsaturated ketone can reach 99% in the oxidation coupling reaction system. The synthetic method is environment friendly and has high atom economy and reaction efficiency. Moreover, the synthetic method uses non-noble metal catalyst, so that the production cost is greatly reduced.

By the antiviral screening of an in house library of pyrazoline compounds, 4-(3-(4-phenoxyphenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide (5a) was identified as a promising hit compound for the development of anti- Yellow Fever Virus (YFV)

Owing to the chiral recognition capacity of bifunctional thioureas, a stereoablative retro-sulfa-Michael reaction has been developed. Utilization of a biphasic system enabled us to render the process catalytic. The usefulness of this methodology was further illustrated by the diastereoselective synthesis of all possible stereoisomers of 2,4-diarylthiethanes.

An unprecedented substituent-controlled chemoselective cleavage of C = C double bond or C(sp2)-C(CO) bond along with aerobic phosphorylation of α,β-unsaturated carbonyl compounds with H-phosphonates through a radical process has been disclosed. The current strategy provides an access to β-ketophosphonates under mild conditions with a wide substrate scope.

A unique and efficient approach has been developed for the synthesis of substituted imidazo[1,2-a]pyridines with aminopyridines and chalcones via a one-pot I2-induced aerobic oxidative coupling. The reported reaction proceeded though a tandem Michael addition followed by an intramolecular oxidative amination with high regioselectivity, yields and good functional group tolerance.

A readily available oxo-ReVcatalyst has been shown to promote a one-pot multistep process that involves the Meyer–Schuster rearrangement of alkynols followed by the Diels–Alder cycloaddition of the resulting enones. These reactions were performed under mild conditions in the presence of 5 mol-% of the catalyst to afford the cycloadducts in good yields with almost 100 % endo stereoselectivity. In-depth computational studies of the cycloaddition mechanism provided the preferred geometry of the rhenium complex in the transition state (TS) and corroborated the experimental endo selectivity.

A facile and efficient route for the synthesis of tetrasubstituted imidazoles from amidines and chalcones via FeCl3/I2-catalyzed aerobic oxidative coupling has been developed. This new strategy is featured by high regioselectivity an

A novel approach for the synthesis of a variety of polysubstituted trans-2,3-dihydropyrroles from a wide range of chalcones and β-enamine ketones (esters) via iodine-promoted tandem Michael/cyclization sequence has been developed, affording the desired products in moderate to excellent yields. This methodology is a highly efficient, convenient way to access functionalized 2,3-dihydropyrroles from readily accessible substrates under mild reaction conditions.

A base-promoted oxidative cycloaddition of chalcones with azides in aqueous solution has been developed under transition-metal-free conditions, which provides a green method for the regioselective synthesis of trisubstituted triazoles in good yields.

A new method has been developed for the cross-coupling of aryl halides with β-chloroalkyl aryl ketones and their ester and amide analogs through a domino dehydrochlorination/Pd(OAc)2- catalyzed Heck reaction sequence. The enone intermediates generated in situ reduced the occurrence of side reactions and therefore enhanced the efficiency of the reaction. This reaction exhibited good tolerance to various functional groups on both substrates and provides rapid access to a wide range of chalcone derivatives.

The first Fe-facilitated decarboxylative cross-coupling reaction between α-oxocarboxylic acids and acrylic acids in aqueous solution has been developed. This transformation is characterized by its wide substrate scope and good functional group compatibility utilizing inexpensive and easily accessible reagents, thus providing an efficient and expeditious approach to an important class of α,β-unsaturated carbonyls frequently found in bioactive compounds. The synthetic potential of the coupled products is also demonstrated in subsequent functionalization reactions. Preliminary mechanism studies suggest that a free radical pathway is involved in this process: the generation of an acyl radical from α-oxocarboxylic acid via the excision of carbon dioxide followed by the addition of an acyl radical to the α-position of the double bond in acrylic acid then delivers the α,β-unsaturated carbonyl adduct through the extrusion of another carbon dioxide.

C-C bond-forming reactions are important in chemistry for construction of complex large molecules from readily available simple substrates. However, they usually involve the employment of organic halides and suffer from toxic or environmental issues. We report an efficient and environmentally benign methodology-aerobic oxidative cross-coupling of primary and secondary alcohols-to directly produce α,β-unsaturated ketones that are key intermediates for synthesis of agrochemical, pharmaceutical, and other fine chemicals. A noble-metal-free Co-N-C catalyst, derived from pyrolysis of cobalt-phenanthroline complexes on a mesoporous carbon support, is developed toward the target reactions and shows high catalytic activity (turnover frequency of 3.8 s-1 based on Co single atoms, surpassing the state of art in the literature), good recyclability, and wide applicability to diverse substrates (28 examples). The active sites in the Co-N-C catalyst are proposed to be Co single atoms bonded with N within graphitic sheets.

Waste minimization is a very important aspect of an environmentally benign protocol. A one-pot consecutive process has been developed for chalcone epoxide synthesis that allows compounds to be prepared without having to isolate and purify the intermediates. The strategy utilizes consecutive Claisen Schmidt condensation and epoxidation reactions to prepare chalcone epoxides from substituted benzaldehydes and acetophenones in good yields.

I likes rearrangements: Hypervalent iodine compounds can be used as environmentally friendly, mild, and selective reagents for highly enantioselective rearrangements of alkenes. For the first time, rearrangements to α-arylated ketones can be performed enantioselectively using lactic acid-based iodine(III) reagents. Copyright

A biomimetic method has been developed to transform α,β-epoxy ketones or 1,2-diketones into corresponding β-hydroxy ketones or α-hydroxy ketones using a catalytic amount of BNAH or BNA +Br-. The regeneration of BNAH or BNA+Br - is achieved by a mixture of HCOOH/Et3N. A radical mechanism is proposed to explain these observations.

A pincer-Pd complex was utilized in the chemoselective transfer hydrogenation of α,β-unsaturated ketones using n-BuOH as a hydrogen source and solvent. Good to excellent yields were obtained for various substrates even with reducible groups. Based on deuterium-labeling experiments, the reaction mechanism is proposed to occur via a pincer-Pd-hydride intermediate.

A series of 1-methyl-3,5-diphenyl-4,5-dihydro-1H-pyrazoles (3a-k and 4a-u) were designed, synthesized, and evaluated for their inhibitory efficacy towards the two hMAO isoforms. Most of the derivatives were found to be potent and selective hMAO-B inhibitors. In particular, derivative 3g showed greater hMAO-B affinity than selective inhibitor selegiline coupled with high selectivity index (SI = 145). The most selective hMAO-B inhibitor was the 3-methyl analogue 3f with an SI higher than 909.

A new type of water-soluble polymer-supported NADH co-enzyme model-PAA (polyacrylic acid)-supported Hantzsch 1,4-dihydropyridine ester (PAA-HEH) was designed and synthesized. Catalytic amount of the supported reagent was used in the hydrogenation of α,β-epoxy ketones to the corresponding β-hydroxy ketones and showed great catalytic efficiency in the reduction reaction. This PAA-HEH was an optimal potential for recycling use.

It has been found that readily available 3-benzoylacrylic acids undergo palladium-catalyzed decarboxylative arylation with arylboronic acids in the presence of a copper salt oxidant to produce chalcone derivatives. The decarboxylative arylation could also be achieved using aryl halides as the alternative aryl source to expand the applicable scope.

Several chalcones were synthesized and their in vitro cytotoxicity against various human cell lines, including human breast adenocarcinoma cell line MCF-7, human lung adenocarcinoma cell line A549, human prostate cancer cell line PC3, human adenocarcinoma cell line HT-29 (colorectal cancer) and human normal liver cell line WRL-68 was evaluated. Most of the compounds being active cytotoxic agents, four of them with minimal IC50 values were chosen and studied in detail with MCF-7 cells. The compounds 1, 5, 23, and 25 were capable in eliciting apoptosis in MCF-7 cells as shown by multiparameter cytotoxicity assay and caspase-3/7, -8, and -9 activities (p 0.05). The ROS level showed 1.3-fold increase (p 0.05) at the low concentrations used and thus it was concluded that the compounds increased the ROS level eventually leading to apoptosis in MCF-7 cells through intrinsic as well as extrinsic pathways.

Lithium amidoborane (LiNH2BH3, LiAB for short), is capable of chemoselectively reducing α,β-unsaturated ketones to the corresponding allylic alcohols at ambient temperature. A mechanistic study shows that the reduction is via a double hydrogen transfer process. The protic H(N) and hydridic H(B) in amidoborane add to the O and C sites of the carbonyl group, respectively.

In this study, a series of novel β-mercapto carbonyl derivatives (3a-j) was prepared by addition of thiophenol (2) to chalcones (1a-j) in the presence of catalytic amount of iodine (10 mol%) in CH2Cl 2. Antibacterial and antifungal in vitro properties of the synthesized compounds were tested against some human pathogenic microorganisms by employing the disk diffusion technique. For the most active compounds, also minimum inhibitory concentrations (MICs) were determined. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

A highly enantioselective copper-catalyzed conjugate addition of diethylzinc to acyclic aromatic enones was developed with phosphoramidite ligands bearing a D2-symmetric biphenyl backbone. This type of reaction demonstrated that toluene and THF solvents can completely reverse the absolute configuration of the products, thus simplifying the process of accessing either enantiomer (S: 92% ee, 94% yield; R: 99% ee, 96% yield).

A highly enantioselective copper-catalyzed conjugate addition with triethylaluminium was developed using phosphoramidite ligands bearing a D 2-symmetric biphenyl backbone. For these ligands we demonstrated that the 3,3',5,5'-substituents on the biphenyl backbone can completely reverse the absolute configuration of the products. Copyright

Re catalysis in one-pot reactions: An atom-economical, one-pot strategy that involves alkyne deprotonation and a subsequent rhenium(V)-catalysed Meyer-Schuster rearrangement of the alkynol to provide α,β- unsaturated enones in high yield has been developed (see scheme). Subsequent in situ hydride reduction or Diels-Alder reaction of the enones provided products in good-to-high overall yields. Copyright

The crossed-conjugate addition involving the electronwithdrawing group (EWG) of activated alkenes is considered one of the most important C-C bond-forming reactions in organic synthesis. Among them, the β,β-disubstituted nitroolefins as powerful synthons have attracted considerable attention recently because the functionalized products can undergo transformations into useful skeletons. Asymmetric intermolecular crossed-conjugate addition between β-alkyl nitroalkenes and a,b-unsaturated carbonyl compounds to provide allylic nitro compounds with multiple stereogenic centers is still rare. The key challenges are to avoid the homo-crossed addition and realize perfect stereochemical control. Shi and co-workers developed the first asymmetric crossed-conjugate addition of β-alkyl nitroalkenes and enals catalyzed by a chiral diphenylprolinol though a dual activation strategy using a stoichiometric amount of (MeO)3P as a Lewis base (LB) (Scheme 1, path A). Although the secondary amines proved to be effective catalysts in the crossed-Michael addition of nitro activated olefins to carbonyl compounds through the LB nucleophilic mechanism, the enantioselective process awaits further investigation.We envisioned that a chiral diamine catalyst would promote the enantioselective crossed-conjugate addition by a bifunctional activation approach (Scheme 1, path B). Herein, we report the chiral primary-secondary diamine Bronsted acid catalyzed asymmetric crossed-conjugate addition of β-methyl nitroalkenes with α, β-unsaturated acyclic and cyclic ketones with excellent enantioselectivities under mild conditions.

A new, efficient protocol for the highly stereoselective one-pot synthesis of (E)-styryl ketones from styrenes based on sequential ruthenium-catalyzed silylative coupling-rhodium-catalyzed desilylative acylation reactions is reported.

In an effort to develop new antimicrobial agents, a series of chalcone derivatives, 3-60, were prepared by Claisen-Schmidt condensation of appropriate acetophenones and 2-furyl methyl ketones with appropriate aromatic aldehydes, furfural, and thiophene-2-carbaldehyde in an aqueous solution of NaOH and EtOH at room temperature. The synthesized compounds were characterized by means of their IR- and NMR-spectral data, and elemental analysis. All compounds were tested for their antibacterial and antifungal activities by the disc diffusion method. For the most active compounds, also minimum inhibitory concentrations (MICs) were determined.

Enantioselective Michael addition of malononitrile to chalcones was catalyzed by a simple quinine and Al(OiPr)3 complex and products were obtained in good ee as well as high yields, which facilitated the asymmetric synthesis of a biologically active 4H-pyran compound. The Royal Society of Chemistry 2009.

Novel 3-(4,6-diarylpyrimidin-2-yl)-2-phenylthiazolidin-4-ones are synthesized by the multicomponent cyclocondensation reaction of the appropriate 2-amino-4,6-diarylpyrimidines, benzaldehyde, and thioglycolic acid catalyzed by dicyclohexylcarbodiimide. The

A series of substituted pyrazolines were synthesized and evaluated for their anticancer activity and for their ability to inhibit P-glycoprotein- mediated multidrug resistance by direct binding to a purified protein domain containing an ATP-binding site and a modulator interacting region. Compounds 2a and e have been found to bind to P-glycoprotein with greater affinity.

A novel series of 1-acetyl-3,5-diphenyl-4,5-dihydro-(1H)-pyrazole derivatives have been synthesised and investigated for the ability to inhibit selectively monoamine oxidases, swine kidney oxidase, and bovine serum amine oxidase. The newly synthesised compounds 1-6 proved to be reversible and non-competitive inhibitors of all types of the assayed amine oxidases. Compounds inhibit monoamine oxidases potently, displaying low I50 values of particular interest. In particular 1-acetyl-3-(2,4-dihydroxyphenyl)-5-(3-methylphenyl)-4,5-dihydro-(1H)-pyrazole 6 showed to be a potent monoamine oxidase inhibitor with a Ki of about 10-8 M. Further insights in the theoretical evaluation of the possible interactions between the compounds and monoamine oxidase B have been developed through a computational approach.

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The base-catalysed condensation of benzaldehydes with acetophenones is enhanced by electron-withdrawing substituents in both starting compounds.The magnitude of ρ-value obtained for various substituents in the benzaldehyde moiety decreases with the introduction of electron-withdrawing groups in the para position of acetophenone moiety.