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Deposition of α-synuclein (α-syn) aggregates is one of the neuropathological hallmarks of synucleinopathies including Parkinson’s disease, dementia with Lewy bodies, and multiple-system atrophy. In vivo detection of α-syn aggregates with SPECT or PET may be an effective tool for medical intervention against synucleinopathy. In the present study, we designed and synthesized a series of chalcone analogues with different aryl groups to evaluate their potential as α-syn imaging probes. In competitive inhibition assays, aryl groups markedly affected binding affinity and selectivity for recombinant α-syn aggregates. Chalcone analogues with a 4-(dimethylamino)phenyl group bound to both α-syn and amyloid β (Aβ) aggregates while ones with a 4-nitrophenyl group displayed α-syn-selective binding. In fluorescent staining, only chalcone analogues with a 4-nitrophenyl group succeeded in selective detection of human α-syn against Aβ aggregates in patients’ brain samples. Among them, PHNP-3 exhibited the most promising binding characteristics for α-syn aggregates (Ki = 0.52 nM), encouraging us to further evaluate its utility. Then, a 125I-labeling reaction was performed to obtain [125I]PHNP-3. In a binding saturation assay, [125I]PHNP-3 bound to α-syn aggregates with high affinity (Kd = 6.9 nM) and selectivity. In a biodistribution study, [125I]PHNP-3 exhibited modest uptake (0.78% ID/g at 2 min after intravenous injection) into a normal mouse brain. Although there is room for improvement of its pharmacokinetics in the brain, encouraging in vitro results in the present study indicate that further structural optimization based on PHNP-3 might lead to the development of a clinically useful probe targeting α-syn aggregates in the future.

An Efficient Pd@Pro-GO heterogeneous catalyst was developed that can promote the α, β-dehydrogenation of saturated aldehyde and ketones in the yield of 73% ? 92% at mild conditions without extra oxidants and additives. Pd@Pro-GO heterogeneous catalyst was synthesized via two steps: firstly, the Pro-GO was obtained by the esterification reaction between graphene oxide (GO) and N-(tert-Butoxycarbonyl)-L-proline (Boc-Pro-OH), followed by removing the protection group tert-Butoxycarbonyl (Boc), which endowed the proline-functionalized GO with both the lewis acid site (COOH) and the bronsted base site (NH), besides, the pyrrolidine of proline also can form imine with aldehydes to activate these substrates; Second, palladium was dispersed on the proline-functionalized GO (Pro-GO) to obtained heterogeneous catalyst Pd@Pro-GO. Mechanistic studies have shown that the Pd@Pro-GO-catalyzed α,β-dehydrogenation of saturated aldehyde and ketones was realized by an improved heterogeneously catalyzed Saegusa oxidation reaction. Based on the obove characteristics, the Pd@Pro-GO will be widely used in the transition metal catalytic field.

The hydroformylation of terminal arylalkynes and enynes offers a straightforward synthetic route to the valuable (poly)enals. However, the hydroformylation of terminal alkynes has remained a long-standing challenge. Herein, an efficient and selective Rh-catalyzed hydroformylation of terminal arylalkynes and conjugated enynes has been achieved by using a new stable biphosphoramidite ligand with strong π-acceptor capacity, which affords various important E-(poly)enals in good yields with excellent chemo- and regioselectivity at low temperatures and low syngas pressures.

The oxidation of alcohols to aldehydes is a powerful reaction pathway for obtaining valuable fine chemicals used in pharmaceuticals and biologically active compounds. Although many oxidants can oxidize alcohols, only a few hydrogen peroxide oxidations can be employed to continuously synthesize aldehydes in high yields using a liquid-liquid two-phase flow reactor, despite the possibility of the application toward a safe and rapid multi-step synthesis. We herein report the continuous flow synthesis of (E)-cinnamaldehyde from (E)-cinnamyl alcohol in 95%-98% yields with 99% selectivity for over 5 days by the selective oxidation of hydrogen peroxide using a catalyst column in which Pt is dispersed in SiO2. The active species for the developed selective oxidation is found to be zero-valent Pt(0) from the X-ray photoelectron spectroscopy measurements of the Pt surface before and after the oxidation. Using Pt black diluted with SiO2as a catalyst to retain the Pt(0) species with the optimal substrate and H2O2introduction rate not only enhances the catalytic activity but also maintains the activity during the flow reaction. Optimizing the contact time of the substrate with Pt and H2O2using a flow reactor is important to proceed with the selective oxidation to prevent the catalytic H2O2decomposition.

Nicotinamide N-methyltransferase (NNMT) methylates nicotinamide (vitamin B3) to generate 1-methylnicotinamide (MNA). NNMT overexpression has been linked to a variety of diseases, most prominently human cancers, indicating its potential as a therapeutic target. The development of small-molecule NNMT inhibitors has gained interest in recent years, with the most potent inhibitors sharing structural features based on elements of the nicotinamide substrate and the S-adenosyl-l-methionine (SAM) cofactor. We here report the development of new bisubstrate inhibitors that include electron-deficient aromatic groups to mimic the nicotinamide moiety. In addition, a trans-alkene linker was found to be optimal for connecting the substrate and cofactor mimics in these inhibitors. The most potent NNMT inhibitor identified exhibits an IC50 value of 3.7 nM, placing it among the most active NNMT inhibitors reported to date. Complementary analytical techniques, modeling studies, and cell-based assays provide insights into the binding mode, affinity, and selectivity of these inhibitors.

3-(Hetero)aryl propenals or propenones are efficiently prepared by a Heck reaction of (hetero)aryl bromides and acrolein or vinyl ketones using Beller's CataCXium Ptb ligand under Jeffery's and Fu's conditions. The formation of these three-carbon building blocks is embedded into consecutive three- and pseudo-four-component syntheses of 3-(hetero)aryl and 3,5-diarylpyrazoles with a broad substitution pattern in moderate to excellent yield.

3-(2-Haloacyl)-2-oxazolidinones were shown to react with enals in an asymmetric SmI2-promoted Reformatsky reaction to give stereochemically well-defined 3-hydroxy-4-alkenyl- and 3-hydroxy-2-methyl-4-alkenyl imides. Chirality transfer of the Evans (S)-oxazolidinone unit via a Zimmerman-Traxler-like transition state resulted in Reformatsky products with a relative syn-configuration. The absolute configuration of compounds obtained is opposite to the corresponding products obtained via aldol addition of boron enolates to enals using the same Evans oxazolidinones.

A highly regioselective reaction between allylzinc bromide reagents and α,β-unsaturated oxime ethers for the one-step synthesis of the homoallylic amines is reported. This process is a regioselective 1,2-addition reaction providing a new γ-position with carbon-carbon bond formation. Furthermore, the reaction substrates are widely applicable and can be produced in a high yield.

A simple, efficient, and environmentally benevolent regioselective oxidative cleavage of 1-arylbutadienes to cinnamaldehydes mediated by iron(III) sulfate/O2 has been developed. The reaction offered good yields and excellent regioselectivity and showed good functional group tolerance (31 examples). The method is important, as few reports with limited substrate scope are available for such excellent oxidative cleavage of conjugated dienes.

Inhibition of S. aureus diapophytoene desaturase (CrtN) could serve as an alternative approach for addressing the tricky antibiotic resistance by blocking the biosynthesis of carotenoid pigment which shields the bacterium from host oxidant killing. In this study, we designed and synthesized 44 derivatives with piperonyl scaffold targeting CrtN and the structure-activity relationships (SARs) were examined extensively to bring out the discovery of 21b with potent efficacy and better hERG safety profile compared to the first class CrtN inhibitor benzocycloalkane derivative 2. Except the excellent pigment inhibitory activity against wild-type S. aureus, 21b also showed excellent pigment inhibition against four pigmented MRSA strains. In addition, H2O2 killing and human whole blood killing assays proved 21b could sensitize S. aureus to be killed under oxidative stress conditions. Notably, the murine study in vivo validated the efficacy of 21b against pigmented S. aureus Newman, vancomycin-intermediate S. aureus Mu50 and linezolid-resistant S. aureus NRS271.

Diazonium salts, and precisely arenediazonium o-benzenedisulfonimides, have been used for the first time as efficient electrophilic partners in gold catalyzed Heck-coupling reactions. The synthetic protocol was general, easy and gave the target products in satisfactory yields. Mechanistic insights revealed the fundamental roles of the o-benzenedisulfonimide anion as an electron transfer agent thath promotes a radical pathway that does not require the presence of photocatalysts or external oxidants.

We report useful new lithium-assisted asymmetric anion-accelerated amino-Cope rearrangement cascades. A strategic nitrogen atom chiral auxiliary serves three critical roles, by (1) enabling in situ assembly of the chiral 3-amino-1,5-diene precursor, (2) facilitating the rearrangement via a lithium enolate chelate, and (3) imparting its influence on consecutive inter- or intramolecular C-C or C-X bond-forming events via resulting chiral enamide intermediates or imine products. The mechanism of the amino-Cope rearrangement was explored with density functional theory. A stepwise dissociation-recombination mechanism was found to be favored. The stereochemistry of the chiral auxiliary determines the stereochemistry of the Cope product by influencing the orientation of the lithium dienolate and sulfinylimine fragments in the recombination step. These robust asymmetric anion-accelerated amino-Cope enabled cascades open the door for rapid and predictable assembly of complex chiral acyclic and cyclic nitrogen-containing motifs in one pot.

We report the catalytic chromium-mediated oxidation of secondary allylic alcohols to give α,β-unsaturated aldehydes with exclusive (E)-stereoselectivity. This facile procedure employs catalytic PCC (5?mol?%) and periodic acid (H5IO6) as a co-oxidant. This transformation occurs specifically with aromatic substituted allyl alcohols containing both electron withdrawing and electron donating substituents as well as a range of functional groups.

A novel method for organocatalytic oxidation through oxidative enamine catalysis was developed with excellent compatibility for the direct syntheses of enals from simple saturated alcohols. By using this amine-catalyzed IBX-oxidation, a wide range of aromatic and aliphatic substituted enals were successfully generated in high yields and exclusively stereoselective E-geometry. Moreover, varying the solvents and/or the loading amounts of IBX allowed for the selective oxidation of alcohols and aldehydes. Importantly, the homologous application of this method provided a selective and efficient way of preparing various highly sensitive conjugated polyene frameworks, which are enriched in natural products.

An approach for supporting a Pd-NHC complex on a soluble star polymer with nanoscale dimensions is described. The resulting star polymer catalyst exhibits excellent activity in cross-coupling reactions, is stable in air and moisture, and is easily recoverable and recyclable. These properties are distinct and unattainable with the small-molecule version of the same catalyst.

The Heck reactions of various aryl halides with olefins using {[Ph2PCH2PPh2CH = C(O)(C10H7)] PdCl2} as efficient catalyst has been investigated. The mononuclear palladacycle complex showed excellent activity in aqueous phase including the C(sp 2)-C(sp 2) cross coupling reactions. The advantages of the protocol are high yields, short reaction time, a cleaner reaction profile and notable simplicity.

The present invention provides a compound represented by the following formula (I), a pharmaceutically acceptable salt thereof, or a solvate thereof. wherein: R1 and R2 are each separately selected from the group consisting of hydrog

A series of p-nitro substituted trans-diphenylbutadienes is synthesized and their photophysical and photochemical properties are investigated. All the dienes have a very low quantum yield of fluorescence but exhibit remarkable solvatochromic emission shifts attributed to twisted intramolecular charge transfer. Photochemical irradiation of simple p-nitro substituted diphenylbutadienes reveals inefficient or no detectable photoisomerization. However, substituting a methyl group on the butadiene chain of p-nitro substituted diphenylbutadiene or replacing the nitro group with cyano group yields the corresponding trans-cis isomers. In the case of simple nitrodienes, strong intramolecular charge transfer character in the excited state aids dissipation of absorbed energy through non-photochemical and non-radiative channels. The steric effect caused by the presence of methyl group lowers the isomerization barrier in methyl substituted dienes leading to a regioselective isomerization.

A novel catalytic enantioselective methodology based on synergistic catalysis is reported. The strategy involves: 1) the metal-Lewis-acid activation of alkylazaarenes, and 2) the secondary-amine activation of enals. Consequently, highly functionalized chiral alkylazaarenes were obtained in good yields and with reasonable stereoselectivity.

Phosphorylation of amines, alcohols, and sulfoximines are accomplished using molecular iodine as a catalyst and H2O2 as the sole oxidant under mild reaction conditions. This method provides an easy route for synthesizing a variety of phosphoramidates, phosphorus triesters and sulfoximine-derived phosphoramidates which are of biological importance.

A one-pot transformation of aldehydes into α,β-unsaturated aldehydes was developed using both N-benzyl-N-methylamine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as catalysts and MnO2 as a terminal oxidant. An oxidative and enantioselective reaction of aldehydes and nitromethane was established using both diphenylprolinol silyl ether and DDQ as a catalyst with MnO2 as a terminal oxidant, in which synthetically important β-substituted γ-nitro aldehydes were obtained with excellent enantioselectivity. Copyright

An aerobic oxidation of allylic alcohols using Fe(NO3) 3·9H2O/TEMPO/NaCl as catalysts under atmospheric pressure of oxygen at room temperature was developed. This eco-friendly and mild protocol provides a convenient pathway to the synthesis of stereodefined α,β-unsaturated enals or enones with the retention of the C-C double-bond configuration.

A nucleophilic substitution of allylic alcohols with carbon (arene, heteroarene, allyltrimethylsilane, and 1,3-dicarbonyl compound), sulfur (thiol), oxygen (alcohol), and nitrogen (sulfonamide) nucleophiles has been demonstrated using an in house developed [Ir(COD)(SnCl3)l(μ-Cl)]2 heterobimetallic catalyst in 1,2-dichloroethane to afford the corresponding allylic products in moderate to excellent yields. In 4-hydroxycoumarin, allylation occurs at the 3-position. The diaryl-substituted allylic alcohols undergo disproportionation in presence of the heterobimetallic catalyst to provide the corresponding alkenes and chalcones. An electrophilic mechanism is proposed from Hammett correlation study.

A new direct oxidative transformation of 3-aryl propionaldehydes to 3-aryl acroleins promoted by SOMO catalysis has been realized with high efficiency under mild reaction conditions.

A mild and highly efficient amine-catalyzed, IBX-mediated oxidation of aldehydes to (E) selective α,β-unsaturated aldehydes has been achieved in good yields. The process features a new oxidation of enamines to iminium ions in a catalytic fashion.

A novel route for the synthesis of 1-aryl-9H-xanthen-9-ones is reported. This methodology involves the condensation of 2-methylchromone with cinnamaldehydes leading to (E,E)-2-(4-arylbuta-1,3-dien-1-yl)-4H-chromen-4-ones. The final steps involved electrocyclization and oxidation of the latter compounds, in an one-pot synthesis, giving the desired 1-aryl-9H-xanthen-9-ones. Georg Thieme Verlag Stuttgart - New York.

A series of simple desmethoxy analogues of coruscanone A was prepared via a novel version of Ti(iPrO)4-mediated Knoevenagel condensation of cyclopentenedione with substituted benzaldehydes and cinnamic aldehydes, and the compounds were evaluated for antifungal activity and cytotoxicity. The most potent 2-benzylidenecyclopent-4-ene-1,3-dione possessed antifungal effect comparable to coruscanone A and a somewhat broader spectrum of activity against Candida species. The compound was also superior to fluconazole against several non-albicans Candida sp. Evaluation of the ability of the compound to influence cell proliferation using two different assays showed that 2- benzylidenecyclopent-4-ene-1,3-dione has lower cytotoxicity compared to the natural product.

Twelve imidazole based Y-shaped push-pull chromophores have been designed, synthesised and fully characterised featuring 4,5-bis(N,N-dimethylanilino) imidazole as a donor moiety, a systematically enlarged π-linker and nitro and cyano groups as acceptors.

α,β-Unsaturated aldimines were specifically oxidized to amides with Oxone in the presence of AlCl3 as a Lewis acid in CH2Cl2. No migration of aryl group occurred in the rearrangement reaction. Copyright Taylor & Francis Group, LLC.

Arylcyclopropanes react with nitrosyl chloride activated by sulfur(VI) oxide to give the corresponding 5-aryl-4,5-dihydro-1,2-oxazoles in quantitative yields. The complex NOC1?2SO3 is a highly efficient nitrosating agent which makes it possible to involve in the process arylcyclopropanes having both donor and acceptor substituents in the aromatic ring. Nauka/Interperiodica 2007.

Palladium catalyzed facile method for alkenylation and alkynylation of arylhalides in good to excellent yield under microwave condition is reported.

Arenediazonium o-benzenedisulfonimides can be used as new and efficient reagents for Heck-type arylation reactions of some common substrates containing C-C multiple bonds, namely ethyl acrylate, acrylic acid, acroleyne, styrene and cyclopentene. The reactions were carried out in an organic solvent, in the presence of Pd(OAc)2 as pre-catalyst, and gave rise to arylated products, for example, ethyl cinnamates, cinnamic acids, cinnamic aldehydes and stilbenes, possessing an (E)-configuration, and 1-arylcyclopentenes, in good to excellent yields. It is noteworthy that all the reactions led to the recovery, in greater than 80% yield, of o-benzenedisulfonimide, recyclable for the preparation of other diazonium salts.

Vanadium(V) (5 mol %) and hydroxamic acid ligand (45 mol %) were found to promote the selective tert-butyl hydroperoxide-mediated oxidation of allylic and propargylic alcohols to the corresponding aldehydes and ketones.

The in situ oxidation-Wittig reaction, followed by subsequent hydrolysis, has been applied to the conversion of primary alcohols into α,β -unsaturated aldehydes. This conversion, which proceeds via the intermediacy of the homologated unsaturated dioxolanes, gives good to excellent yields with a range of benzylic alcohols and heterocyclic methanols.

(Matrix presented) The reaction of aryl iodides and bromides with acrolein diethyl acetal in the presence of Pd(OAc)2, nBu 4NOAc, K2CO3, KCl, and DMF, at 90°C until the disappearance of the acetal followed by the addition of 2 N HCl to the crude reaction mixture, affords cinnamaldehydes in good to high yields. A variety of functional groups are tolerated in the aryl halides, including ether, aldehyde, ketone, ester, dialkylamino, nitrile, and nitro groups. The presence of substituents close to the oxidative addition site does not hamper the reaction.

The Heck arylation of α,β-unsaturated aldehydes is strongly dependent on the catalyst, the solvent and the base. Optimized conditions yielded either selectively cinnamyl derivatives (83%) or double arylation products (88% based on aryl conversion). A new α-arylation of β,β-disubstituted acrolein is also realized.

Novel sulfate ester agents and the use of those agents for treating gastroesophageal reflux disease (GERD) are described, exemplary agents being of the formula: wherein X is —OCH2— or —CH2O—; Y is a group pendant from X comprising at least one —OSO3R4 moiety, wherein R4 is H or a pharmaceutically acceptable cation; n is an integer from 1-3; and R1 and R2 are each independently selected from the group consisting of —H, a halogen with an atomic number from 9 to 53, —SO3R4, —NCS, —NCO, —NH(CO)—OR3, —NH(CS)SR3, —NH(C═NH)OR3, —NHCOCH2Cl, —NHCOCH2Br, —NHCO—CH═CH2, —NHC(O)—CF3, wherein R4 is H or a pharmaceutically acceptable cation.

A series of polymer-bound imidazolium chlorochromates have been synthesised and used as selective oxidants for benzylic and cinnamylic alcohols. Solid-support-bound 1-amino-imidazolium chlorochromate proved to be the most convenient system due to its efficiency, selectivity and ease of recycling the material.

An aldolase antibody, 24H6, which was obtained from immunization with the large hapten 2, is shown to possess an active-site lysine residue with a perturbed pK(a) of 7.0. This antibody catalyzes both the aldol addition and the retrograde aldol fragmentation with a broad range of substrates that are structurally different from the hapten. This observation suggests that in reactive immunization with 1,3-diketones, the hapten structure governs the chemistry but not the overall organization of the active site. Hammett correlation studies of the 38C2- and 24H6-catalyzed aldol and retroaldol reactions revealed that although the two antibodies exhibit broad substrate specificities, they utilize slightly different mechanisms. While antibody 38C2 adopts a mechanism that is reminiscent of an acid-catalyzed aldol reaction, antibody 24H6 follows a mechanism that is similar to the base-catalyzed reaction.

Two carbon homologation of aromatic and heterocyclic aldehydes is achieved by reacting them with acetaldehyde enolate anion generated in situ by cleaving vinyl acetate in the presence of barium hydroxide.

A simple and readily available oxidation of primary allylic and benzylic alcohols to the corresponding aldehydes is carried out by sodium bismuthate in acetic acid.

Novel triazole compounds with a dioxane ring were synthesized. Condensation of the diol precursor 10 with various aromatic aldehydes 11 - 13 under acidic conditions afforded a series of dioxane-triazole compounds 14 - 16. The antifungal activities of the compounds 14 - 16 were evaluated in vivo in mice infection models against Candida and Aspergillus species. High activities were seen for the derivatives with one or two double bond(s) and an aromatic ring substituted with an electron-withdrawing group in the side chain. Among the derivatives, R-102557 (16R: Ar=4-(2,2,3,3- tetrafluoropropoxy)phenyl) showed excellent in vivo activities against Candida, Aspergillus and Cryptococcus species. It also showed high tolerance in a preliminary toxicity study in rats.

A convenient procedure for the synthesis of E-olefins bearing electron donor-acceptor groups is reported. A new diethyl N-aryl aminobenzylphosphonate (1d) was synthesized. Reactivity of Wittig-Horner reaction is compared. Expansion of the π-conjugate chain involves the reduction of N-methoxy-N-methyl amide to aldehyde by reaction with DIBAL-H.

A structure-activity relationship study with a series of aldol substrates shows that the mechanism of the antibody 38C2-catalyzed retrograde aldol reaction depends on the nature of the substrate with electron-deficient substrates an early deprotonation precedes the C-C bond cleavage while with electron-rich substrates the catalytic mechanism involves an initial C-C bond cleavage leading to a positively charged intermediate.

Aldehydes were efficiently transformed into allylic dioxolanes by a Wittig-type reaction, using 1,3-dioxolan-2-yl-methyltriphenylphosphonium bromide under phase transfer conditions. The substituent kinetic effects were studied, and related to Hammett values and electrochemical potentials.

A series of 3-styryl-1,5-diphenyl and 5-styryl-1,3-diphenyl 2- pyrazolines of different substitutions has been synthesized by condensation of substituted α,β-unsaturated ketones with phenylhydrazine hydrochloride in presence of catalytic amount of concentrated HCl. Compounds in the 3- styryl series had OMe, NMe2, NO2, OH and isopropyl substituents and those in the 5-styryl series had OMe, NMe2 and NO(s). The 3-styryl-1,5-diphenyl compounds showed little variation in antibacterial activity towards gram- positive and gram-negative bacteria in terms of geometric mean minimum inhibitory concentrations (MIC). The 4',4-NMe2, 4',4-NO2 and 4',4-OMe compounds were found to possess the highest activity in the series. The 5- styryl-1,3-diphenyl series showed lower activities than the 3-styryl series. The in vitro antimycotic activity of the 4',4-OH and 2',2-OH substituted compounds showed good activity than the other molecules in the two series.

1,3-Dithianes 1, 1,3-dithiolanes 2, and diphenyl dithioacetals 3 derived from cinnamaldehydes reacted with 2,3-dichloro-5,6-dicyano-p-benzoquinone in aqueous solvents to give benzaldebydes 4. Hydride transfer from 1-3 to 2,3-dichloro-5,6-dicyano-p-benzoquinone followed by hydrolysis and oxidative carbon-carbon bond cleavage would produce benzaldehydes 4.

A new facile route to (2E,4E)-dienals by a double formyl-olefination with arsonium salts has been developed. By this method and with other arsonium reagents in the key step some lipoxygenase metabolites of arachidonic acid, lipoxin A4 and B4 and leukotriene B4, have been synthesized.

Bacteriorhodopsin analogues BR-I, BR-II and BR-III containing azo chromophores 4-[[4'-(N,N-dimethylamino)phenyl-1']azo]benzaldehyde, 3-[4-[[4'-(N,N-dimethylamino)phenyl-1']azo]phenyl-1]prop-2-enal and 3-[4-[[4'-(N,N-dimethylamino)phenyl-1']azo]phenyl-1]-2

2-tri-n-Butylstannylvinyl ethers are useful synthetic equivalents of acetaldehyde in 2-carbon homologation reactions.When reacted with aldehydes in the presence of BF3-OEt2 the corresponding trans-α,β-unsaturated aldehydes are obtained in high yield.