Abstract An asymmetric 1,6‐conjugate addition of thioacetic acid with para ‐quinone methides has been developed by using chiral phosphoric catalysis in the presence water. A series sulfur‐containing compounds were thus obtained high yields good to excellent enantioselectivities. Theoretical studies indicated that water‐bridged proton transfer is a potentially favorable reaction pathway. unprecedented O−H⋅⋅⋅π interaction between water and aromatic nucleus was discovered contribute...

Abstract The discovery of modern medicine relies on the sustainable development synthetic methodologies to meet needs associated with drug molecular design. Heterocycles containing difluoromethyl groups are an emerging but scarcely investigated class organofluoro molecules potential applications in pharmaceutical, agricultural and material science. Herein, we developed organophotocatalytic direct difluoromethylation heterocycles using O 2 as a green oxidant. C–H oxidative obviates need for...

Abstract Atomic-scale doping strategies and structure design play pivotal roles in tailoring the electronic physicochemical property of electromagnetic wave absorption (EMWA) materials. However, relationship between configuration (EM) loss mechanism has remained elusive. Herein, drawing inspiration from DNA transcription process, we report successful synthesis novel situ Mn/N co-doped helical carbon nanotubes with ultrabroad EMWA capability. Theoretical calculation EM simulation confirm that...

In light of the crucial role marine ecosystems and escalating environmental conservation challenges, it is essential to conduct monitoring help implement targeted protection measures efficiently. Energy harvesting technologies, particularly triboelectric nanogenerators (TENGs), have great potential for prolonging lifespan enhancing reliability sensors in remote areas. However, high internal resistance, low current, friction-induced abrasion issues TENGs limit their performance practical...

A copper-mediated C–S/N–S bond–forming reaction via C–H activation that uses elemental sulfur has been developed. The addition of TBAI was found to be crucial for the success this transformation. method is scalable, shows excellent functional group tolerance, and compatible with heterocycle substrates, providing efficient practical access benzoisothiazolones. direct diversification benzoisothiazolone products into a variety sulfur-containing compounds also demonstrated.

Abstract The first catalytic asymmetric construction of a new class bispirooxindole scaffold‐containing tetrahydro‐β‐carboline moiety has been established through chiral phosphoric acid‐catalyzed three‐component cascade Michael/Pictet–Spengler reactions isatin‐derived 3‐indolylmethanols, isatins, and amino‐ester, which afforded structurally complex diverse bispirooxindoles with one quaternary tetrasubstituted stereogenic centers in excellent stereoselectivities (all >95:5 diastereomeric...

Abstract An N‐heterocyclic carbene (NHC) catalyzed dihalomethylenation of enals is described. It a rare example merging NHC catalysis with single‐electron chemistry, challenging topic limited previous success. The versatile carbon‐centered trihalomethyl radicals have been demonstrated, for the first time, to be compatible an NHC‐bound intermediate, thus leading efficient and regioselective intermolecular C−C bond formation. mild process provides straightforward access unsaturated δ,δ‐dihalo esters.

A highly efficient method to access axially chiral anilides through asymmetric allylic alkylation reaction with achiral Morita-Baylis-Hillman carbonates by using a biscinchona alkaloid catalyst was reported. Through the atroposelective approach, broad range of anilide products different acyl groups, such as substituted phenyl, naphthyl, alkyl, enyl, styryl, and benzyl, were generated very good yields, moderate excellent cis: trans ratios, enantioselectivities. The can be scaled up, synthetic...

A number of popular squaramide organocatalysts' acidities were determined by an overlapping indicator method in DMSO via UV spectrophotometric titrations. The pKa values are the range 8.37–16.46. results may be helpful for rational design and development type new catalysts.

The pKa values of 41 chiral phosphoric acid-family catalysts in DMSO were predicted using the SMD/M06-2x/6-311++G(2df,2p)//B3LYP/6-31+G(d) method for first time. study showed that calculated pKa's range from -4.23 to 6.16 absolute and -4.21 6.38 relative values. Excellent agreement between experimental was achieved few available cases (to a precision around 0.4 unit), indicating this strategy may be suitable calculating highly accurate pKa's. A good linear correlation 3 3' disubstituted...

Abstract We herein demonstrated an efficient method for the atroposelective construction of nine‐membered carbonate‐bridged biaryls through vinylidene ortho ‐quinone methide (VQM) intermediates. Diverse products with desirable pharmacological features were synthesized in satisfying yields and good to excellent enantioselectivities. In subsequent bioassays, several agents showed considerable antiproliferative activity via mitochondrial‐related apoptosis mechanism. Further transformations...

Heterohelicenes are of increasing importance in the fields materials science, molecular recognition, and asymmetric catalysis. However, enantioselective construction these molecules, especially by organocatalytic methods, is challenging, few methods available. In this study, we synthesize enantioenriched 1-(3-indol)-quino[n]helicenes through chiral phosphoric acid-catalyzed Povarov reaction followed oxidative aromatization. The method has a broad substrate scope offers rapid access to an...

Biofilms significantly impede the efficacy of conventional antimicrobial agents, particularly in multidrug-resistant (MDR) infections. In this work, we developed a size-adaptive, bismuth-based nanomicrobicide encapsulated with neutrophil membranes (Bi2S3/SNP@CM), designed to selectively generate nitric oxide (NO) within acidic biofilms under near-infrared (NIR) irradiation. The nanomicrobicide's adaptive size ensures deeper biofilm penetration and accumulation, while membrane coating...

Acidity effect: Correlations of pKa with catalytic activity and stereoselectivity were determined linear free energy relationships (LFERs) observed for both pKa−log (k) (R/S) correlations in meta- and/or para-substituted aromatic thioureas (see figure). These results provided a basis new catalyst development several improved catalysts identified our initial attempts. Detailed facts importance to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but...

Abstract A simple alkylthiourea was found to be an effective catalyst for the Michael addition reaction of 3‐substituted oxindole nitroolefins. number 3,3′‐substituted derivatives, which have two vicinal quaternary‐tertiary chiral centers were synthesized with up 99% yield, 19:1 dr and 98% ee .

A giant Goos-Hänchen (G-H) shift in graphene has been theoretically predicted by previous research. In this Letter, we present experimental measurements of the G-H graphene, a total internal reflection condition, using new method have named "the beam splitter scanning method." Our results show that focused light source undergoes significant lateral when polarization incident changes from transverse magnetic (TM) to electric (TE) mode, indicating large is polarization-dependent. We also...

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXTEnantioselective Organocatalyzed Sulfenylation of 3-Substituted OxindolesXin Li*, Cong Liu, Xiao-Song Xue, and Jin-Pei Cheng*View Author Information State-key Laboratory Elementoorganic Chemistry Department Chemistry, Nankai University, Tianjin, 300071, P.R. China[email protected]; [email protected]Cite this: Org. Lett. 2012, 14, 17, 4374–4377Publication Date (Web):August 2012Publication History Received4 July 2012Published online17 August inissue 7...

The pKa values of a series chiral Brønsted acids, including N-triflylphosphoramides, bis(sulfonyl)imides, bis(sulfuryl)imides, dicarboxylic sulfonic and N-phosphinyl phosphoramides, were predicted by using the SMD/M06-2x/6-311++G(2df,2p)//B3LYP/6-31+G(d) method in DMSO. results revealed that calculated ranged from −9.06 to 12.18 for different types acids. influence acidic strength on reactivity stereoselectivity was discussed acidity data. Given choice catalyst with appropriate is primary...

Abstract The chiral benzofuranone structural motif is a prominent feature in many natural products, which exhibit broad range of biological and pharmaceutical activities. In the past few years, survey derivatives based on asymmetric catalysis reveals an increasing number papers, reflects latest achievements to facilitate synthesis sufficient quantities related compounds as potential medicinal agents probes. Recent advances this area are summarized classified according structure starting...

A ring-opening C(sp³)–C coupling of cyclobutanone oxime esters for the preparation cyanoalkyl containing heterocycles was realized under visible-light or sunlight irradiation.

A chiral squaramide catalyzed approach constructing spiro-3,4-dihydrocoumarin motif by the enantioselective 1,6-addition/acetalization reactions of 1-oxotetralin-2-carbaldehydes and ortho-hydroxyphenyl-substituted para-quinone methides followed an oxidation was developed. The proceeded smoothly with a wide range p-QMs to generate corresponding products in high yields excellent diastereoselectivities (>19:1 dr) enantioselectivities (up 99% ee).

Green and efficient C–C bond cleavage/cyanoalkylation of quinoxalin-2(1H)-ones other heteroarenes under visible light or sunlight irradiation is described. The reaction proceeds mild conditions at room temperature without transition-metal catalysts extra bases. Notably, the products enable facile transformations to various significant organic compounds.

The enantioselective ketimine-ene reaction is one of the most challenging stereocontrolled types in organic synthesis. In this work, catalytic reactions 2-aryl-3H-indol-3-ones with α-methylstyrenes were achieved by utilizing a B(C6 F5 )3 /chiral phosphoric acid (CPA) catalyst. These proceed well low catalyst loading (B(C6 /CPA=2 mol %/2 %) under mild conditions, providing rapid and facile access to series functionalized 2-allyl-indolin-3-ones very good reactivity (up 99 % yield) excellent...