We developed a simple, compact microfluidic device to perform high dynamic-range digital polymerase chain reaction (dPCR) in an array of isolated 36-femtoliter microreactors. The density of the microreactors exceeded 20,000/mm². This device, made from polydimethylsiloxane (PDMS), allows the samples to be loaded into all microreactors simultaneously. The microreactors are completely ...

From the ethyl acetate fraction of the fruiting body of Ganoderma lucidum, a new triterpenoid, ethyl 7β-hydroxy-4,4,14α-trimethyl-3,11,15-trioxo-5α-chol-8-en-24-oate (4), named ethyl lucidenates A, along with three known compounds, ganodermanondiol (1), lucidumol B (2) and methyl lucidenates A (3) were isolated by silica gel column, ODS column chromatography and PHPLC. Their structures ...

N,N'-Dibenzyl-6-hydroxymethyl-6-nitroperhydro-1,4-diazepine was converted into a nitronate via retro-Henry reaction, followed by either Michael reaction with several acrylic derivatives or Mannich reaction with different amines, thus leading to 6-substituted 6-nitroperhydro-1,4-diazepines. The tandem retro-Henry/Mannich reaction was also carried out using benzylamine as base, solvent, and reagent at the same time. Selective hydrogenation ...

A series of new aurantiamide acetate analogues were synthesized by modifying its N-terminal substitution and the amino acid residue. The structure of all these compounds was established on the basis of analytical and spectral studies. All the new derivatives were evaluated in vivo for their analgesic activity by tail flick ...

A method for the assembly of tricyclic structures containing the peroxide, monoperoxyacetal, and acetal moieties was developed based on the acid-catalyzed reaction of beta,delta-triketones with H2O2. Tricyclic compounds are formed selectively in yields from 39 to 90% by the reactions with the use of large amounts of strong acids, such ...

A dually NHC-catalyzed reaction cascade comprising an initial hydroacylation of an activated ketone and subsequent Sonogashira/Heck/Suzuki coupling in the same pot is reported. The reaction mechanism and scope of the methodology is presented.

Neat and tidy: B(C(6) F(5) )(3) efficiently converts a series of bis(alkynyl)phosphanes into highly substituted 3-borylphospholes through a twofold 1,1-carboboration reaction sequence. The boron substituted phospholes were also used as substrates in Suzuki-Miyaura type cross-coupling reactions.

Ozonolysis is a major tropospheric removal mechanism for unsaturated hydrocarbons and proceeds via "Criegee intermediates"-carbonyl oxides-that play a key role in tropospheric oxidation models. However, until recently no gas-phase Criegee intermediate had been observed, and indirect determinations of their reaction kinetics gave derived rate coefficients spanning orders of magnitude. Here, ...

We have developed an efficient procedure for the easy and straightforward preparation of functionalized dihydropyridazines as highly enantiopure materials by reaction of pyruvaldehyde 2-tosyl hydrazone with a variety of α,β-unsaturated aldehydes using a chiral secondary amine as catalyst. The overall process consists of a cascade reaction involving an initial aza-Michael ...

Condensation reactions of procyanidin dimer B4 with two representative oak wood cinnamic aldehydes (coniferaldehyde and sinapaldehyde) were conducted in wine-like model solutions. Coniferaldehyde led to the formation of guaiacylcatechin-pyrylium-catechin (GCP-catechin, 737 m/z), whereas sinapaldehyde led to the formation of syringylcatechin-pyrylium-catechin (SCP-catechin, 767 m/z). The former was also structurally characterized by ...

From the organic extracts of two Guam sponges, Rhaphoxya sp. and Suberea sp., determined to have cytotoxic and chemopreventive activities, three new compounds, theonellin isocyanate (1) and psammaplysins I and J (5, 6), and six previously reported compounds (2-4, 7-9) were isolated and characterized spectroscopically ((1)H and (13)C NMR, MS, ...

Routinely employed syntheses of terminally deuterated alkynes often utilize strong bases (i.e., LDA, n-BuLi, or Grignard reagents) or low (i.e., -78 °C) or elevated (i.e., 56 °C) reaction temperatures; furthermore many of these procedures afford average yields and in some cases less than optimum deuterium incorporation. Herein we report the ...

Tetrabutylammonium fluoride has been found to catalyze the deacylation of cellulose esters. More surprisingly, the deacylation is highly regioselective. Even more remarkably, in contrast to the C-6 regioselectivity of other reactions of cellulose and its derivatives, this deacylation shows substantial selectivity for removal of the acyl groups from the esters ...

1,3,3a,7a-Tetra-hydro-2-benzofuran was used as key compound for the synthesis of various bishomo-inositol derivatives. The diene was subjected to an epoxidation reaction for further functionalization of the diene unit. The bisepoxide obtained was submitted to a ring-opening reaction with acid in the presence of water. Various bishomoinositols were synthesized. However, when ...

An unprecedented intramolecular Petasis condensation provides a novel approach to biologically important conduramines. The compounds are produced with an exclusive anti stereoselectivity for the newly created β-amino alcohol motif. The stereochemical outcome of the reaction is opposite to the one usually observed in the intermolecular reaction.

The occurrence of a range of recalcitrant organic micropollutants in our aquatic environment has led to the development of various tertiary wastewater treatment methods. In this study, biogenic manganese oxides (Bio-MnOx), biogenic silver nanoparticles (Bio-Ag(0) ) and ionic silver were used for the oxidative removal of the frequently encountered drug ...

3-Aroyl and 3-heteroaroyl substituted 3-oxoalkanenitriles were synthesized by the reactions of activated aromatic and hetero-aromatic substances with cyanoacetic acid in the presence of acetic anhydride. As part of studies focusing on the preparation of cyanoacetyl-1-N-methylbenzimidazole, we observed that reaction of N-methyl-benzimidazole with the cyanoanhydride formed by condensation of cyanoacetic acid ...

The removal of endocrine-disrupting compounds (EDCs) by lignin peroxidase from white-rot fungus Phanerochaete sordida YK-624 (YK-LiP1) was investigated. Five endocrine disruptors, p-t-octylphenol (OP), bisphenol A (BPA), estrone (E(1)), 17β-estradiol (E(2)), and ethinylestradiol (EE(2)) were eliminated by YK-LiP1 more effectively than lignin peroxidase from P. chrysosporium (Pc-LiP), and OP and BPA ...

There has been growing interest in the use of modified-carbon-nanotube electrodes in applications such as the electrochemical detection of biologically significant compounds, owing to their apparent "electrocatalytic" properties and ability to enhance oxidative signals. In spite of their salient properties, little work has been done to further examine the reasons ...

A dramatic enhancement of the diastereo- and enantioselectivity in the nitro-Michael addition reaction organocatalysed by a commercially available α,α-l-diaryl prolinol was disclosed when performing the reaction in unconventional hexafluorobenzene as a medium. DFT calculations were performed to clarify the origin of stereoselectivity and the role of C(6)F(6).

Scope: The distribution and accumulation of olive oil phenolic compounds in the body are topics lacked of information. The aim of this study was to evaluate the bioavailability, metabolism and distribution of phenolic compounds from olive cake. Methods and results: The metabolism and distribution of phenolic compounds were examined by ...

Benzo[f]pyrido[1,2-a]indole-6,11-diones have been synthesized in high yields by copper(II) catalyzed three-component reactions of acyl bromide, 1,4-naphthoquinone, and pyridine (or isoquinoline) via sp2-C-H difunctionalization of naphthoquinone followed by intramolecular cyclization and oxidative aromatization. Without the Cu(II) catalyst, the reactions give low yields with the formation of by-products, while in the presence ...

Herein we report the total syntheses of pseudoceramine A-D (2-5) and spermatinamine (1) isolated from the marine sponge Pseudoceratina sp. Direct acyl substitution of α-hydroxyiminoesters with amine nucleophiles was developed as a key transformation. The synthetic compounds confirm the reported structures and importantly gives access to non-symmetrical spermine based natural ...

Mild reaction conditions for Petasis reactions of substituted salicylaldehydes with various amines and arylboronic acids in the presence of molecular sieves were developed. Molecular sieves (MS) significantly accelerated the reaction rates and drove the reactions to high conversions. The conditions were applied to the synthesis of the core structure of ...

A combined computational and experimental kinetic study on the Henry reaction is reported. The effects of solvation on the transition structures and the rates of reaction between nitromethane and formaldehyde, and between nitropropane and benzaldehyde are elucidated with QM/MM calculations.

Iridium complexes show high catalytic activity in intermolecular additions of acid chlorides to terminal alkynes to afford valuable (Z)-β-chloro-α,β-unsaturated ketones. Ligands in the catalytic system play a crucial role in this reaction. An N-heterocyclic carbene (NHC) is an efficient ligand for the addition of aroyl chlorides, while dicyclohexyl(2-methylphenyl)phosphine (PCy2(o-Tol)) is ...

Activated red mud (ARM) samples were tested for carbon monoxide (CO) oxidation in the temperature range of 100-500°C. Conversion of >90% was obtained for temperatures above 400°C for all samples. In order to study the effect of hydroxylated phases of iron oxide in red mud on the removal of CO, ...

Ferrocence and its derivatives have long been known to be a class of stable organometallic compounds, and their dissociation usually occurs under harsh conditions. Here we report a new type of ferrocene derivatives, 4,4-difluoro-8-ferrocenyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene and 4,4-difluoro-2,6-diethyl-8-ferrocenyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene, which surprisingly can hydrolyze under mild conditions. These two derivatives, initially developed as donor-acceptor ...

It all adds up! A modified Feist-Bénary reaction employing a domino Michael-alkylation sequence was designed for the enantioselective synthesis of 3(2 H)-furanones. L-Threonine-derived tertiary amine/thiourea catalysts were prepared for the first time; such catalysts promoted the designed domino Michael-alkylation reactions in a highly enantioselective manner.

Metals are the key players in the synthesis of caralacton, a strong inhibitor of bacterial biofilms. The total synthesis is based on several metal-mediated key transformations such as the Ley and the Duthaler-Hafner aldol reactions, the Marshall reaction and Breit's substitution, as well as the Nozaki-Hiyama-Kishi and Negishi-Fu CC coupling ...

The solvolysis of α-D-glucopyranosyl fluoride in hexafluoro-2-propanol gives two products that are 1,1,1,3,3,3-hexafluoropropan-2-yl α-D-glucopyranoside and 1,6-anhydro-β-D-glucopyranose. The ratio of these two products is essentially unchanged for reactions that are performed between 56 and 100 °C. The activation parameters for the solvolysis reaction are ΔH‡ = 81.4 ± 1.7 kJ mol-1 ...

A new triarylphosphine-tertiary amine bifunctional polymeric reagent has been prepared and used effectively in a variety of one-pot Wittig reactions. The design of this reagent resolved a deficiency of a previously reported related material, and allowed it to perform more efficiently in such reactions. Furthermore, it was readily recyclable, and ...

Birth of a silanol nest: Reaction paths for the extraction of Al and Si from zeolites by reaction with steam were investigated by first-principles DFT calculations. The results show that dealumination is energetically favored over desilication (see picture: O red, Si yellow, Al purple, H white).

We report the use of a previously intractable nucleophile, anisole, in an oxidative "Cross Dehydrogenative Coupling" (CDC) reaction with the cyclic ether isochroman, as well as derivatives of both components. Metal catalysis was required for the reaction to proceed efficiently, and the reaction is highly sensitive to modification of either ...

[Ir(cod)Cl]2/BINAP was found to be an efficient catalyst for the [2+2+2] cycloaddition of alpha,omega-diynes with isocyanates to give 2-pyridones. A wide range of isocyanates can be used for this reaction. Both aliphatic and aromatic isocyanates smoothly reacted with alpha,omega-diynes to give 2-pyridones in high yields. Aliphatic isocyanates were more reactive ...

The synthesis of beta-hydroxy-gamma-amino acids via SmI2-mediated Reformatsky reactions of alpha-chloroacetyloxazolidinones with aminoaldehydes is reported. Diastereoselective coupling is demonstrated to depend on the absolute configuration of the Evans chiral auxiliary employed in the reaction, allowing erythro or threo products to be obtained selectively. The potential utility of the methodology is ...

Novel injectable hydrogels have been formed at 37°C under physiological pH using a polymer-polymer crosslinking reaction. Three different formulations were tested. After 1-day cure time at body temperature, the elastic modulus of unswollen samples ranged between 3 and 5 kPa but after 11 additional days at 4°C exceeded the target ...

For most ectotherms, increasing the rearing temperature reduces the final (adult) body size, producing a negative slope for the thermal reaction norm. Recent studies show that this relationship may be reversed under conditions of low resource quality, producing a positive slope for the thermal reaction norm. If populations or species ...

An iron-copper cooperative catalysis is shown to be effective for alkene-Grignard exchange reaction and alkylmagnesiation of alkynes. The Grignard exchange between terminal alkenes (RCH=CH2) and cyclopentylmagnesium bromide was catalyzed by FeCl3 (2.5 mol %) and CuBr (5 mol %) in combination with PBu3 (10 mol %) to give RCH2CH2MgBr in ...

We developed a heat-processing method to enhance the antioxidant activity of koji. The superoxide anion scavenging activity (SOSA) and oxygen radical absorbance capacity (ORAC) of heat-processed koji (HP-koji) at 55°C for 7days were 4.9 times and 4.2 times, respectively, those of unheated koji. These results showed that heat processing effectively ...

Stereodivergent catalytic asymmetric conjugate reactions of glycine (ket)imine with nitroalkenes have been achieved under varied chiral catalyst systems derived from a multidentate amino alcohol 1. The stepwise nature of the [3 + 2] cycloaddition reactions of N-metallated azomethine ylides has also been demonstrated by highly enantio- and diastereoselective synthesis of ...

We report herein the synthesis of 4-amino-2,8-dichloro-pyrido[3,2-d]pyrimidine derivatives 2 and their regioselective diversification through SNAr and metal-catalyzed cross-coupling reactions. While amination of 2 took place selectively at C-2, the regioselectivity of thiol or thiolate addition depended on the reaction conditions. Selective C-8 addition was obtained in DMF with Hünig's base, ...

The influence of a laccase from Trametes versicolor on the removal of phenolic monomers in liquid hot water pretreated wheat straw supernatants (LHW-S) was examined. Beside the total phenol content derived by Folin-Ciocalteu (FC-) assay, phenolic monomers were measured via headspace-solid phase micro-extraction (HS-SPME)/GC-MS. A notable decrease of the phenols ...

Two new Zn(II) and Cd(II) MOFs have been synthesized. These MOFs have been applied as heterogeneous catalysts for the green synthesis of a variety of dihydropyrimidinone derivatives through the Biginelli reaction and the desired products were obtained in high yields with short reaction time under mild solvent- free conditions. Moreover, ...

The first enantioselective Neber reaction of β-ketoxime sulfonates catalyzed by a bifunctional thiourea has been developed. The reaction proceeds stereoselectively with 5 mol % of the catalyst to give the 2H-azirine carboxylic esters in good yields with up to 93% ee. In addition, the resulting azirines can be successfully employed ...

PGD(2) is a key mediator of allergic inflammatory diseases that is mainly synthesized by mast cells, which constitutively express high levels of the terminal enzyme involved in PGD(2) synthesis, the hematopoietic PGD synthase (H-PGDS). In this study, we investigated whether eosinophils are also able to synthesize, and therefore, supply biologically ...

A short reaction sequence leads to oligoarene derivatives utilising a regioselective Scholl reaction for the unprecedented cyclisation to the mono-functionalised oligoarene under methanol elimination. Quantum-chemical investigations reveal the reason for the remarkably high regioselectivity.

There is a sufficient body of work documenting the distribution of 3-hydroxy oxylipins in microbes. However, there is limited information on the role of these compounds in microbial pathogenesis. When derived from mammalian cells, these compounds regulate patho-biological processes, thus an understanding of 3-hydroxy oxylipin function and metabolism could prove ...

A tandem one-pot method for the construction of a pyridine moiety with selective control of substitution patterns has been developed through the sequential reactions of nitrile with a Reformatsky reagent and 1,3-enyne involving regio- and chemoselective addition of the Blaise reaction intermediate to 1,3-enyne, followed by isomerization, cyclization, and an ...

The Diels-Alder cycloaddition reaction of oxazole with ethylene is facilitated by addition of an alkyl group or Brønsted or Lewis acids to the oxazole nitrogen atom. The efficacy consists of stabilizing the transition state, lowering the activation barrier and the HOMO(dienophile)-LUMO(diene) gap, and increasing the reaction exothermicity.