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ABSTRACT With the blooming of ocean construction engineering, the influence of seawater on concrete durability draws increasing attentions. This paper investigates the performances of five high performance concrete (HPC) pastes, [...]

Diamide insecticides have gained popularity due to their high efficacy and low toxicity to nontarget organisms. However, diamide-associated resistance has emerged recently, causing a significant reduction in their potency, thereby hindering sustainable agricultural development. Here, we explored novel diamide insecticide analogs and, using a structure-based approach, rationally designed and synthesized 28 nitrophenyl substituted anthranilic diamides. Most of the compounds showed moderate to good activity against Mythimna separata, Plutella xylostella, and Spodoptera frugiperda. Among them, compounds Iaand Imshowed extraordinarily high activity and their mode of action was verified on isolated neurons. Additionally, Imexhibited over 10-fold greater potency than chlorantraniliprole in a HEK293 cell line stably expressing S. frugiperdaryanodine receptors (SfRyRs) containing the resistance mutations, G4891E and I4734M. The binding modes of Imin the SfRyRs were predicted using in silico molecular docking analysis. Our novel nitrophenyl substituted anthranilic diamide derivatives provide valuable insights for the design of insecticidal RyR-targeting compounds to effectively control both wild type and diamide insecticide-resistant lepidopteran pests.

ABSTRACT Manufactured sand (MS) is widely considered as an alternative of the river sand (RS) recently, and to clarify the influence significance and influence mechanism of MS characteristic parameters on [...]

We developed a visible-light-mediated [3 + 2] cycloaddition of arylcyclopropylamine with structurally diverse olefins using QXPT-NPhas a highly efficient organic photoredox catalyst. We first achieved the use of various alkyl-substituted alkenes in intermolecular [3 + 2] cycloadditions with cyclopropylamine. We also developed a general and efficient strategy for the construction of structurally diverse cyclopentane-based spiro[4.n] skeletons with 1,3-difunctional groups, which broadly exist in natural products and synthetic molecules. Furthermore, we proposed a hydrogen-bond mode between the arylcyclopropylamine and the photocatalyst QXPT-NPh.

Concise and scalable formal syntheses of (−)-quinocarcinamide and (−)-quinocarcin have been achieved in 9 steps with 9% overall yield from simple commercially available chemicals. The synthetic strategy features an ortho-regioselective Pictet–Spengler cyclization for the construction of the tetrahydroisoquinoline skeleton, a stereoselective formal intramolecular [3 + 2] cross cycloaddition of cyclopropane 1,1-diester with an imine for the construction of the 3,8-diazabicyclo[3.2.1]octane skeleton.

The study aims to realize the recycling of the heavier portion of bio-oil produced in pyrolysis to achieve a higher char yield in a two-stage fixed bed. Simultaneously, the influence of condensation temperature in the second-stage reactor on the obtained char yield was probed as well. For further investigation on the physicochemical properties of char samples, ultimate analysis, N2adsorption–desorption measurements, Raman spectroscopy, and Fourier-transform infrared spectroscopy analysis were conducted. In addition, the reactivity of char samples in air was determined using a thermogravimetric analyzer. The results suggested that the char samples produced by the recycling of heavy oil resulted in a relatively high yield. Simultaneously, different condensation temperatures of the second layer during pyrolysis had a significant impact on the experimental results: as the temperature increased, the char yield and the O/C molar ratio decreased, whereas the value of IG/IALLincreased. Finally, it was found that the increase of condensation temperature in the second layer led to the decline of char reactivity. The dimensionless index (DI) was used to show the physicochemical properties of char, and a linear relationship between the oxidation activity index and DI was achieved, which could be used to predict the char reactivity based on the physicochemical properties for industrial applications.

The nicotinic acetylcholine receptor (nAChR) is one of the targets for developing drugs for the treatment of central nervous system (CNS) disorders and for control of agricultural pests. Pyrido[3,4‐b] homotropane (PHT) was originally designed and synthesized by Kanne and co‐workers and showed strong affinity binding to nAChR. PHT has a novel aza‐[4.2.1]nonane skeleton. Owing to its excellent biological activities and novel chemical structure, synthetic and medicinal chemists have been attracted by this molecule. Some PHT analogues with bridged aza‐[n.2.1] skeletons were also designed and synthesized via different strategies. Herein, we summarize the syntheses of PHT and its analogues. Their biological activity study is also briefly discussed. Hit the bull's eye! Pyrido[3,4‐b]homotropane (PHT) and its analogues have been proven to be potential synthetic nicotinic acetylcholine receptor (nAChR) ligands with bridged aza‐[n.2.1] skeletons. This Minireview gives a brief summary of the recent progress in the syntheses of PHT and its analogues, as well as their biological activity study.

Fatigue crack damage in the epoxy asphalt concrete pavement of long-span steel bridge deck is still one of the most severe problems even though the fatigue endurance performance has been studied for a long time. In this study, it aimed at exploring the mechanism why the fatigue damage of the epoxy asphalt concrete occurred, as well as finding out the reason why fatigue test results in laboratory were different from those in practical engineering application. A finite element mechanics method was first applied to analyze the maximum strain value of the epoxy asphalt concrete pavement at different load positions, then fatigue performance of the epoxy asphalt concrete was investigated using a four-point bending fatigue testing method, and finally a three-parameter fatigue equation model, which was demonstrated to be feasible and rational, was utilized to determine fatigue endurance limit for the first time. The fatigue damage of the epoxy asphalt concrete occurred in a short time once the strain level with driving load was larger than fatigue endurance limit. In contrast, the fatigue damage did not appear in a long time if the strain level was less than the fatigue endurance limit. It is suggested that the fatigue endurance limit be adopted as a control parameter in the design phase of epoxy asphalt concrete pavement. These findings advance previous design specifications in the world, and could help extending service life of epoxy asphalt concrete pavement of long-span steel bridge deck.

A Lewis acid catalyzed domino aldol/homo‐Michael reaction of formylcyclopropane 1,1‐diesters with dicarbonyls has been successfully developed. This method provides efficient and direct construction of highly functionalized furans from easily available starting materials.

Ein Baustein, zwei Brücken: Die Wahl der katalysierenden Lewis‐Säure (LS, π: π‐elektrophil, σ: σ‐elektrophil) bestimmt den Reaktionsweg ([4+2] oder [3+2]) von katalytischen intramolekularen Cycloadditionen (IMCCs) eines Alkinylcyclopropan(ACP)‐Ketons. Mit dieser allgemeinen Methode gelingt der stereoselektive Aufbau verschiedener verbrückter Oxa‐/Aza‐[n.3.1]‐ und Oxa‐/Aza‐[n.2.1]‐Gerüste (siehe Schema).

Build a bridge:The first catalytic intramolecular [3+2] cycloaddition of monodonor–monoacceptor cyclopropanes (see scheme) provides a general and efficient strategy for construction of structurally diverse acetal[n.2.1] and 1,4‐dioxygen‐substituted cyclic skeletons, which are widely distributed in biologically important natural products.

Der Biosyntheseweg von Himastatinaus Streptomyces himastatinicuswurde durch Genomanalyse, die Erzeugung von Gendeletionsmutanten und Komplementierungsexperimente aufgeklärt. Drei Cytochrome P450, die neuartige postmodifizierende Oxidationen katalysieren (siehe Bild), werden charakterisiert.

Catalyzed by N‐heterocyclic carbenes (NHCs), a domino ring‐opening/redox amidation/Knoevenagel condensation of readily available formylcyclopropane 1,1‐diesters with 1H‐indole‐2‐carbaldehydes is reported. This methodology provides a new and direct method for the construction of a 6‐5‐5 tricyclic pyrrolo[1,2‐a]indole skeleton.

No Abstract

We report herein an nBuLimediated, expeditious, ringopening rearrangement of arylmethylenecyclopropane 1,1diesters to prepare 1,3diene derivatives with good stereoselectivity. The reaction mechanism has also been discussed.

Taking the lead–zinc deposit of the Huanggang–Ganzhuermiao metallegenic belt as a predicted mine, this article systematically analyzes the relationships between the geological conditions, including strata, magmatic rock, lead–zinc deposit, and so on, and has discovered their control action and the manner of geological conditions on the lead–zinc deposit, and has then established the comprehensive prospecting model for the lead–zinc deposit, which consists of geological, geochemical, and mineralization information, which will provide a theoretical basis for predicting the lead–zinc deposit within the metallegenic belt.

Domino day: A highly diastereoselective Cu‐ or Au‐catalyzed tandem cycloisomerization/formal [4+3] cycloaddition of 1‐(1‐alkynyl) cyclopropyl ketones and nitrones has been developed (see scheme) along with an efficient one‐pot, three‐component version of this reaction. This methodology provides a route to a new type of 5/7‐bicyclic heterocycle: a furan‐fused oxazepine.

Another pathway: A new type of Lewis acid promoted [3+3] cycloaddition of methylenecyclopropane‐1,1‐diesters with C,N‐diarylnitrones is disclosed. This cycloaddition is highly site‐, regio‐, and stereoselective and proceeds in moderate‐to‐excellent yields. A three‐component one‐pot version of the cycloaddition is also reported.

In order to improve the rigidity performance of the hydrostatic thrust bearing, an electro-hydraulic pressure servo system is proposed to adjust oil film pressure in real-time. A rapid prototyping method is adopted to identify the model of the pressure servo system. A non-linear hybrid controller is applied, which is composed of a classical PID controller and a fuzzy controller based on self-adjusting modifying factor and a fuzzy switching mode is employed to reject undesirable disturbances caused by the switchover between the two control methods. The identification model of the practical system and the feasibility of the control scheme are validated by hardware-in-the-loop simulation experiments. The experiments results show that the hybrid PID controller exhibits high bearing rigidity (the maximum overshoot is 0.07, while PID is 0.2), improves stability and rapidity when load changes. Further, the control performance can be enhanced through matching the load rigidity and mass reasonably; and it is feasible to apply electro-hydraulic pressure servo system to hydrostatic thrust bearing.

NHeterocyclic carbenes NHCs catalyze the reaction of formylcyclopropane 1,1diesters with salicylaldehydes in a domino redox esterificationcyclization reaction to give coumarins in moderate to excellent yields. In addition, we also report the intramolecular conversion of compound 2fto dihydropyranone 4catalyzed by NHC D. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008

No Abstract

Abstract. Single microwave extraction of heavy metals Cr, Ni, Zn, Cu, Cd, and Pb by the extractants CaCl₂, EDTA, CH₃COOH and HCl has been established. The experimental conditions were optimized. A microwave power of 60% and an extraction time of 25 min were adopted. Comparison of microwave extraction and conventional extraction methods revealed that results obtained by microwave techniques were generally in a good agreement with those obtained by use of extraction methods; use of the former resulted in substantial time saving and a better precision, however. Microwave extraction was used to evaluate the bioavailability of heavy metals in soils. Single correlation analysis was performed to establish the relationship between the concentrations of the extractable heavy metals in wet rhizosphere soils and their concentrations in wheat (Troticum aestivum L.) grown on the soils under greenhouse conditions. The correlation coefficients between the extractable metals in soils and their concentrations in wheat roots were found to be 0.5398-0.7819, 0.6425-0.8073, 0.5568-0.8276, 0.5851-0.6087 for the extractants CaCl₂, EDTA, CH₃COOH, and HCl, respectively.

AbstractBy a new tandem reaction, in which ethyl 1-pyrazolacetate reacted with carbon disulfide and iodomethane, pyrazolo[5,1-b]thiazole was synthesized. This was an easy method for the synthesis of this type of heterocyles.

AbstractA new synthetic method for methyl 2-benzyloxylphenylacetate, a key intermediate of a new type of fungicides, had been found, which has only 3 steps. The 80% yield of the new method is a major improvement over the 30% 6-step-process reported by the literature.

AbstractA new method was found for the synthesis of pyrazoleacetate esters from pyrazolaldehyde. By a new tandem reaction, in which 4-pyrazoleacetate esters reacted with carbon disulfide and iodomethane, thieno[2,3-c]pyrazole was synthesized. This was an easy method for the synthesis of this type of heterocycles.

An efficient construction of an aza-[5.7.6.5] tetracyclic core structure of calyciphylline D-type Daphniphyllumalkaloids has been achieved. The synthetic route features a diastereoselective cyclopropanation, efficient construction of the core bridged 8-aza-[3.2.1]octane skeleton through a [3 + 2] IMCC strategy, oxidative dearomatization of phenol, and gram-scale preparation in each step.

A new method has been found for the synthesis of pyrazoleacetate esters from pyrazolaldehyde. By a new tandem reaction, in which methyl 4‐pyrazoleacetate was reacted with carbon disulfide and iodomethane, thieno[2,3‐c]pyrazole was synthesized. This was an easy method for the synthesis of this type of heterocycle. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 303–305, 1999

The reaction proceeds without any metal, acid or base.

Various pyran derivatives are synthesized by the title process.

An N‐heterocyclic carbene catalyzed domino ring‐opening/redox amidation/Knoevenagel condensation of indolecarbaldehydes and formylcyclopropanes is reported.

A Lewis acid promoted intramolecular [3+2] cycloaddition of cyclopropane 1,1‐diesters with aldehydes, ketones, and imines is developed to provide a general and efficient strategy for construction of bridged oxa‐ and aza‐[n.2.1] skeletons.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.