The gold-catalyzed cyclization of (Z)-enynols offers an efficient and straightforward route to stereodefined (Z)-5-ylidene-2,5-dihydrofurans fully substituted furans under extremely mild reaction conditions. Importantly, the results indicated that both oxyauration proto-demetalation steps are highly stereoselective.

A structurally well-defined copper(I) isonitrile complex is shown to be an efficient, heterogeneous catalyst for the Huisgen azide-alkyne 1,3-dipolar cycloaddition under mild conditions in water. Notably, this can also utilized a three-component reaction of halides, sodium azide and alkynes form 1,4-disubstituted 1,2,3-triazoles high yields. Furthermore, it readily recovered by precipitation filtration recycled at least five runs without significant loss activity.

[reaction: see text] The gold-catalyzed cyclization reactions of 2-oxo-3-butynoic esters or disubstituted-1,2-diones with a variety nucleophiles are described, which offer an efficient and straightforward route to substituted 3(2H)-furanones under mild reaction conditions. Au(III) catalysts also highly effective in the hydration these activated alkynes.

Abstract Experimental radiative lifetimes for eight odd-parity levels belonging to 4 f 5 d configurations of Sm iii were measured by the time-resolved laser-induced fluorescence method. To our knowledge, four out first time. By combining experimental and theoretical branching fractions derived from Database on Rare Earths at Mons University, transition probabilities oscillator strengths 23 lines derived, two which reported

The palladium-catalyzed aerobic oxidation of alkenes and especially styrenes (Wacker oxidation) by using chiral pseudo C(2)-symmetrical bis(isonitrile) ligands in the absence further cocatalysts gives rise to methyl ketones a highly chemoselective manner. palladium catalyst was characterized NMR spectroscopy X-ray structure analysis, revealing dissymmetric coordination two isonitrile moieties.

Renewable biomass has attracted much attention because of its advantages over fossil fuels. Of these biomasses, anethole been developed as a reliable monomer or precursor for diverse materials with potential applications.

The aim of this article is to highlight recent examples in which two powerful synthetic tools, namely ring‐opening metathesis polymerization (ROMP) and thiol‐ene (including the thiol‐Michael variant) click chemistry have been combined facilitate preparation novel functional materials varying topology. image

Zirconium-induced cyclodimerization of a variety heteroaryl-substituted alkynes is described. This method provides facile synthesis tetrasubstituted cyclobutenes with high regio- and diastereoselectivity. A ligand-induced reductive elimination mechanism accounting for this novel suggested.

The nucleophile initiated thiol-Michael reaction of a wide range mono and multifunctional thiols with novel acrylic exo-7-oxanorbornene is described. We highlight how this process affords ready access to large library thioether-based substrates in quick convenient fashion. New containing, for example, ester, fluoro, siloxy functionality polymerized controlled fashion Grubbs' first generation (G1) catalyst, RuCl2(PCy3)2CHPh, yielding homopolymers controlled, predetermined molecular weights...

Nucleophile-initiated thiol-Michael chemistry was employed to prepare a series of mono- and di-functional exo-7-oxanorbornenes from the reaction between or dithiols with 2-((3aR,7aS)-1,3-dioxo-3a,4,7,7a-tetrahydro-1H-4,7-epoxyisoindol-2(3H)-yl)ethyl acrylate. Homopolymerization difunctional species, bis(2-((3aR,7aS)-1,3-dioxo-3a,4,7,7a-tetrahydro-1H-4,7-epoxyisoindol-2(3H)-yl)ethyl)-3,3′-((1,4-phenylenebis(methylene))bis (sulfanediyl))dipropanoate (M1), Grubbs' first generation catalyst,...

Abstract The strength of filled bolt holes composites is an important parameter in developing the bearing bypass envelope curves for bolted joint structures engineering design. This paper presents procedures tensile failure strengths and damage a laminate with hole. Tests two different cases, open‐hole tension (OHT) filled‐hole (FHT), were performed repeated seven times, respectively. A new type virtual testing based on LaRC05 criteria coupling XFEM crack technique was developed to predict...

The hyperfine structure (HFS) constants and isotope shifts (ISs) for some Cu I II levels were determined by fitting Fourier transform (FT) spectra from the US National Solar Observatory. HFS of 43 31 determined, which 35 results 16 are reported first time, to best our knowledge. Meanwhile, ISs 52 transitions also determined. These respectively cover wavelengths 223.078 2461.4 nm 224.77 1791.747 II. Since in stellar atmosphere copper is mainly present as singly ionized species, new data will...

Direct thioesterification of carboxylic acids with thiols using nontoxic activation agents is highly desirable. Herein, an efficient and practical protocol safe inexpensive industrial waste polymethylhydrosiloxane as the agent K3PO4 18-crown-6 a catalyst described. Various functional groups on acid thiol substituents can be tolerated by present system to afford thioesters in yields 19-100%.

The design of novel heterogeneous glycopolymers with different sugar motifs is critical importance in the glycopolymer field.

Abstract Bolted joints are widely used in aircraft structures. Proper design and accurate strength assessment of these great importance design. In this paper, to investigate the mechanical behavior single lap shear carbon fiber reinforce plastic, four types fastener numerical model methods developed. Based on same principle joint, different double bolt, single‐lap joint structures with three distinct width‐diameter ratios ( w /D) designed manufactured. Each specimen is loaded under tension...

The partition behaviors of some dyes, anthraquinones, and tanshiones in two kinds aqueous two-phase systems (ATPSs) have been investigated. constants (K) ionic dyes rhein the first kind ATPSs are dependent on hydrophobic electrostatic interactions. A correlation for K as a function concentration ratio total surfactant ions surface net charge aggregates between coexisting phases has proposed. Almost 100% water-insoluble electroneutral extract accumulates surfactant-rich phase ATPS due to...

An effective strategy was constructed for the small-scale preparation of AIE-active Pdots, which displayed reversibly distinct dual-color fluorescence in cancer cells.

Artificial metalloenzymes (ArMs) have high potential in biotechnological applications as they combine the versatility of transition-metal catalysis with substrate selectivity enzymes. An ideal host protein should allow high-yield recombinant expression, display thermal and solvent stability to withstand harsh reaction conditions, lack nonspecific metal-binding residues, contain a suitable cavity accommodate artificial metal site. Moreover, its rational functionalization, provide an intrinsic...

Abstract This paper describes the synthesis of 2‐ and 4‐functional acrylic exo ‐7‐oxanorbornene species 2‐((2‐((3a R ,7a S )‐1,3‐dioxo‐1,3,3a,4,7,7a‐hexahydro‐2 H ‐4,7‐epoxyisoindol‐2‐yl)ethoxy) carbonyl)‐2‐methylpropane‐1,3‐diyl diacrylate (((2‐((2‐((3a carbonyl)‐2‐methylpropane‐1,3‐diyl)bis(oxy))bis(carbonyl))bis(2‐methylpropane‐2,1,3‐triyl) tetraacrylate, their use as common precursors for preparation a small library dendronized thioether adducts via nucleophile‐mediated thiol‐ M ichael...