α-AMIDOALKYLATION VIA SULFONES:TOWARDS THE SYNTHESIS OF ANT VENOM ALKALOIDS

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Quantitative Structure-chromatographic Retention Relationship for Polychlorinated Dibenzothiophenes and Their Corresponding Sulfones

Polychlorinated dibenzothiophenes(PCDTs)and their corresponding sulfone(PCDTO2)compounds are a group of important persistent organic pollutants.In the present study,geometrical optimization and subsequent calculations of electrostatic potentials(ESPs)on molecular surface have been performed for all 135 PCDTs and 135 PCDTO2 congeners at the HF/6-31G*level of theory.A number of statistically-based parameters have been extracted.Linear relationship between gas-chromatographic retention index(RI)and the structural descriptors have been established by multiple linear regression.The result shows that two descriptors derived from positive electrostatic potential on molecular surface,σ+^2 andπ,together with the molecular volume(Vmc)and the energy of the lowest unoccupied molecular orbital(ELUMO)can be well used to express the quantitative structure-retention relationship(QSRR)of PCDTs and PCDTO2.Predictive capability of the two models has been demonstrated by leave-one-out cross-validation with the cross-validated correlation coefficient(RCV)of 0.996 and 0.997,respectively.Furthermore,the predictive power of the models is further examined for the external test set.Correlation coefficients(R)between the observed and predicted RI values for the external test set are 0.997 and0.998,respectively,validating the robustness and good prediction of our model.The QSRR model established may provide again a powerful method for predicting chromatographic properties of aromatic organosulfur compounds.

SO_(2)-Insertion induced enantioselective oxysulfonylation to access β-chiral sulfones with quaternary carbon stereocenters

β-Chiral sulfones are structural motifs widely found in natural products and bioactive molecules, while also serving as important intermediates for the synthesis of valuable chiral scaffolds. In contrast to the rapid growth of sulfur dioxide insertion chemistry over the last decade, enantioselective catalytic variants for accessing β-chiral sulfones, especially those bearing a quaternary carbon stereocenter, remain rare. Herein, we report an enantioselective copper/bisoxazoline catalyzed oxysulfonylation of alkenes to yield isoxazolinyl-containing β-chiral sulfones bearing quaternary carbon stereocenters with moderate to excellent yields and up to 96:4 er. The advantage and irreplaceability of this sulfur dioxide insertion catalytic system have been demonstrated by achieving transformations clearly unavailable with the previously reported sulfonyl chloride system. Additionally,the recoverability of the new-developed bisoxazoline ligand L9 and its reusability without any erosion of the catalytic activity and enantioselectivity further demonstrate the usefulness of the protocol.

Copper(Ⅰ)-catalyzed interrupted click/radical relay:A four-component modular synthesis of triazole sulfones

A new,four component copper(Ⅰ)-catalyzed interrupted click/radical relay cascade has been developed.This unprecedented interrupted click reaction provides a rapid modular synthesis of triazole sulfones,important privileged heterocyclic pharmacophores which cannot be accessed by a traditional click reaction.Radical interception of cuprate-triazole,the key reaction intermediate formed in situ,is an important feature of this process.

Stereoselective electrochemical carboxylation ofα,β-unsaturated sulfones

As an attractive C1 synthon,carbon dioxide(CO_(2))has been extensively used in organic synthesis to produce carboxylic acids.In this research,stereoselective electrochemical carboxylation ofα,β-unsaturated sulfones has been developed under transition-metal-free conditions.All the cinnamic acids and the derivatives are obtained selectively in the E-configuration.Besides,arylpropiolates also can be produced from alkynyl sulfones.

Oxidation of aromatic sulfides with molecular oxygen:Controllable synthesis of sulfoxides or sulfones

The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted.The sulfoxides and sulfones could be obtained by simply switching the reaction media,i.e.,bis(2-butoxyethyl)ether(BBE)or poly(ethylene glycol)dimethyl ether(PEGDME).The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents.This strategy represents an economic and eco-friendly method that could find potential applications.

Creating large EMS populations for functional genomics and breeding in wheat

Wheat germplasm is a fundamental resource for basic research,applied studies,and wheat breeding,which can be enriched normally by several paths,such as collecting natural lines,accumulating breeding lines,and introducing mutagenesis materials.Ethyl methane sulfonate(EMS)is an alkylating agent that can effectively introduce genetic variations in a wide variety of plant species.In this study,we created a million-scale EMS population(MEP)that started with the Chinese wheat cultivars‘Luyan 128’,‘Jimai 38’,‘Jimai 44’,and‘Shannong 30’.In the M1 generation,the MEP had numerous phenotypical variations,such as>3,000 chlorophyll-deficient mutants,2,519 compact spikes,and 1,692 male sterile spikes.There were also rare mutations,including 30 independent tillers each with double heads.Some M1 variations of chlorophyll-deficiency and compact spikes were inheritable,appearing in the M2 or M3 generations.To advance the entire MEP to higher generations,we adopted a single-seed descendent(SSD)approach.All other seed composites of M2 were used to screen other agronomically important traits,such as the tolerance to herbicide quizalofop-P-methyl.The MEP is available for collaborative projects,and provides a valuable toolbox for wheat genetics and breeding for sustainable agriculture.

High performance photodegradation resistant PVA@TiO_(2)/carboxyl-PES self-healing reactive ultrafiltration membrane

The occurrence of ultrafiltration(UF)membrane fouling frequently hampers the sustainable advancement of UF technology.Reactive self-cleaning UF membranes can effectively alleviate the problem of membrane fouling.Nevertheless,the self-cleaning process may accelerate membrane aging.Addressing these concerns,we present an innovative design concept for composite self-healing materials based on self-cleaning UF membranes.To begin,TiO_(2)nanoparticles were incorporated into the polymer molecular structure via molecular design,resulting in the synthesis of TiO_(2)/carboxyl-polyether sulfone(PES)hybrid materials.Subsequently,the nonsolvent-induced phase inversion technique was employed to prepare a novel of UF membrane.Lastly,a polyvinyl alcohol(PVA)hydrogel coating was applied to the hybrid UF membrane surface to create PVA@TiO_(2)/carboxyl-PES self-healing reactive UF membranes.By establishing a covalent bond,the TiO_(2)nanoparticles were effectively and uniformly dispersed within the UF membrane,leading to exceptional self-cleaning properties.Furthermore,the water-absorbing and swelling properties of PVA hydrogel,along with its capacity to form hydrogen bonds with water molecules,resulted in UF membranes with improved hydrophilicity and active self-healing abilities.The results demonstrated that the water contact angle of PVA@5%TiO_(2)/carboxyl-PES UF membrane was 43.1°.Following a 1-h exposure to simulated solar exposure,the water flux recovery ratio increased from 48.16%to 81.03%.Moreover,even after undergoing five cycles of 12-h simulated sunlight exposure,the UF membranes exhibited a consistent retention rate of over 97%,thus fully demonstrating their exceptional self-cleaning,antifouling,and selfhealing capabilities.We anticipate that the self-healing reactive UF membrane system will serve as a pioneering and comprehensive solution for the self-cleaning antifouling challenges encountered in UF membranes while also effectively mitigating the aging effects of reactive UF membranes.

Copper-catalyzed 1,1-difunctionalization of terminal alkynes: a three-component reaction for the construction of vinyl sulfones

A copper-catalyzed 1,1-difunctionalization of terminal alkynes was achieved via a three-component reaction, providing a variety of vinyl sulfones with good yields and excellent chemo-and stereoselectivity. Preliminary mechanistic studies indicated that the reaction probably underwent a Cu-catalyzed formal C–H insertion to produce an allene intermediate, which was then trapped by a sulfonyl anion to give the corresponding product.

Electrochemical synthesis of β-hydroxy-, β-alkoxy-, and β-carbonyloxy sulfones by vicinal difunctionalization of olefins

An electrochemical vicinal heterodifunctionalization of olefins for the synthesis ofβ-oxysulfones is described.With suitable choice of the conditions,including current,electrodes,and electrolyte,this oxidation reaction proceeded efficiently in an undivided cell without the use of a stoichiometric chemical oxidant.In addition to the previously established synthesis ofβ-hydroxysulfones in the presence of water,minor modification of this protocol by using either external alcohol nucleophiles or internal carboxylic acid nucleophile also led to the synthesis ofβ-alkoxysulfones,andβ-sulfonyl lactones.

Photocatalytic Aerobic Oxysulfonylation of Alkynes to Access β-Keto Sulfones Catalyzed by OVs-N-Nb_(2)O_(5)

Herein,we report a novel heterogeneous photocatalyst for radical-mediated oxidative oxysulfonylation of alkynes toβ-keto sulfones under environmentally benign conditions.The oxygen vacancy-rich semiconductor Nb2O5(labeled as OVs-N-Nb_(2)O_(5))could efficiently catalyze a wide range of alkynes,especially for those bearing electron-deficient substituents or internal alkynes,to their correspondingβ-keto sulfones in good to high yields with good tolerance of diverse functional groups under visible-light illumination.The late-stage modification of steroidal compounds and synthesis of bioactive molecules were also achieved via this procedure,highlighting its potential for practical applications.Meanwhile,the photocatalyst OVs-N-Nb_(2)O_(5) showed outstanding catalytic stability for successive recycles without appreciable loss in activity and selectivity.The critical role of oxygen vacancies on improving reaction activity and selectivity was clearly disclosed via control experiments and theoretical calculation.

Catalyst-and additive-free selective sulfonylation/cyclization of 1,6-enynes with arylazo sulfones leading to sulfonylated γ-butyrolactams

A convenient and regioselective sulfonylation/cyclization of 1,6-enynes with arylazo sulfones has been developed to access a series of sulfonylated γ-butyrolactams.The present reaction could be efficiently conducted under catalyst-and additive-free conditions,in which C-S and C-C bonds were selectively constructed in one-pot procedure.

One-pot two-step reaction of selenosulfonate with isocyanides and allyl alcohol under aqueous conditions:Atom-economic synthesis of selenocarbamates and allyl sulfones

In many reactions involving selenosulfonate or thiosulfonate,the sutfone group often leaves in form of benzenesutfinic acid or sodium benzenesulfinate.A one-pot two-step reaction of selenosulfonate with isocyanides and allyl alcohol under aqueous conditions to afford selenocarbamates and allyl sulfone compounds is reported.The sulfinic acid as the first-step side product is converted to the allyl sulfone compound by water promoted reaction with allyl alcohol.Water acts as both an oxygen source of selenocarbamates and as a promoter to drive the second step reactio n.The reactions have the advantages of mild conditions,green,environment-friendly,and high atomic economy.

Unexpected Decarboxamidation of a-Arylsulfonyl Weinreb Amides by Grignard Reagents： Synthesis of a-Disubstituted Arylsulfones

An unexpected decarboxamidation of a-arylsulfonyl Weinreb amides as a side reaction under the standardacylating conditions was found in Weirtreb amides chemistry. The control experiments for mechanism study disclosedthat a-sulfo group was necessary, and a-quaternary carbon was the key factor for the reaction. Meanwhile, an effi-cient method was established for the preparation of secondary alkyl arylsulfones by this unexpected C--C bondcleavage reaction using excess Grignard reagent.

Enantioselective Synthesis of Optically Active Bis(β-hydroxy) Sulfones through Asymmetric Hydrogenation of Corresponding Ketones Catalyzed by a Chiral Cationic Ruthenium Diamine Catalyst

Chiral molecules containing sulfonyl and 1,5-diol moieties are useful synthetic blocks for various asymmetric transformations.A protocol has been developed for the enantioselective synthesis of optically active bis(β-hydroxy)sulfones catalyzed by a chiral cationic ruthenium diamine catalyst.A series of bis(β-hydroxy)sulfones have been obtained in excellent yields(up to 99%)with excellent enantioselectivities(up to 99%)as well as good diastereoselectivities(up to 99∶1).

Transition-Metal-Free Reductive Cross-Coupling Employing Metabisulfite as a Connector:General Construction of Alkyl–Alkyl Sulfones

A multicomponent reductive cross-coupling of unactivated alkyl halides and alkyl tosylates connected via sodium metabisulfite was established for the general construction of alkyl-alkyl sulfones.Neither a metal catalyst nor a metal reductant is required in this“green”reductive cross-coupling.Inorganic sodium metabisulfite served as both the sulfur dioxide source and the robust connector.

Enhancing Hydrophilicity of Thick Electrodes for High Energy Density Aqueous Batteries

Thick electrodes can substantially enhance the overall energy density of batteries.However,insufficient wettability of aqueous electrolytes toward electrodes with conventional hydrophobic binders severely limits utilization of active materials with increasing the thickness of electrodes for aqueous batteries,resulting in battery performance deterioration with a reduced capacity.Here,we demonstrate that controlling the hydrophilicity of the thicker electrodes is critical to enhancing the overall energy density of batteries.Hydrophilic binders are synthesized via a simple sulfonation process of conventional polyvinylidene fluoride binders,considering physicochemical properties such as mechanical properties and adhesion.The introduction of abundant sulfonate groups of binders(i)allows fast and sufficient electrolyte wetting,and(ii)improves ionic conduction in thick electrodes,enabling a significant increase in reversible capacities under various current densities.Further,the sulfonated binder effectively inhibits the dissolution of cathode materials in reactive aqueous electrolytes.Overall,our findings significantly enhance the energy density and contribute to the development of practical zinc-ion batteries.

A Janus separator towards dendrite-free and stable zinc anodes for long-duration aqueous zinc ion batteries

Critical issues of Zn anodes including undesirable dendrites formation and parasitic reactions severely limit the reversibility and cyclability of Zn anodes.To address these issues,a functional Janus separator with the structure of a mechanically strong sulfonated poly(arylene ether sulfone)(SPAES)dense layer composited on a porous glass fiber(GF)substrate is designed.The SPAES dense layer that faces the Zn anode containing abundant sulfonic acid groups effectively promotes the desolvation process of hydrated Zn ions,guides uniform Zn ion transfer,and blocks anions and water,contributing to dendrite-free and highly reversible Zn plating/stripping cycles,while the porous GF substrate retains high electrolyte uptake.As a result,the Zn symmetric cell with the Janus separator demonstrates an ultralong cycling lifespan of over 2000 h at the areal capacity of 1 m A h cm^(-2),which is 23-fold superior to that with a pristine glass fiber separator(<90 h).More impressively,the as-prepared Janus separator enables outstanding rate performance and excellent cycling stability of full Zn ion batteries with diverse cathode materials.For instance,when paired with the V_2O_(5)cathode,the full battery with a Janus separator attains an ultrahigh initial specific capacity of 416.3 m A h g^(-1)and capacity retention of 60%over 450 cycles at 1 A g^(-1),exceeding that with a glass fiber separator.Hence,this work provides a facile yet effective approach to mitigating the dendrites formation and ameliorating the parasitic reactions of Zn metal anodes for high-performance Zn ion batteries.

Boron separation by adsorption and flotation with Mg-Al-LDHs and SDBS from aqueous solution

Layered double hydroxides(LDHs)have been shown to be effective adsorbents for boron.However,solid-liquid separation is still a problem when separating boron from industrial radioactive waste liquid.In this research,three types of Mg-Al-LDHs including Mg-Al-LDH(NO_(3)^(-)),Mg-Al-LDH(Cl^(-))and Mg-Al-LDH(SO_(4)^(2-))were applied to adsorb boron,and moreover sodium dodecylbenzenesulfonate(SDBS)was used to float the LDH particles from aqueous solution after boron adsorption.The results showed that 60 min was sufficient for the equilibrium adsorption of the three LDHs.The boron adsorption capacity of three LDHs was determined as follows:Mg-Al-LDH(NO_(3)^(-))>Mg-Al-LDH(Cl^(-))>Mg-Al-LDH(SO_(4)^(2-)),and was 2.0,0.98 and 0.2 mmol·g^(-1),each ranging from 0 to 80 mmol·L^(-1)with the initial boron concentration.The efficiency of boron removal by Mg-Al-LDH(NO_(3)^(-))and SDBS can reach up to 89.7%.Furthermore,the boron flotation mechanism of SDBS and LDHs has been studied,since SDBS as a flotation agent can react with LDHs and penetrate into the interlayer of LDHs in addition to electrostatic attraction.Therefore,LDHs in solution can be floated onto the foam layer to be separated from the solution,and the clarified solution was obtained.The method is simple and promising for boron removal from aqueous solution.

Taurine:an essential amino sulfonic acid for retinal health

Taurine(2-amino-ethanesulfonic acid)is a naturally occurring amino sulfonic acid derived from cysteine and methionine metabolism.Its common name derives from the ox,as it was first isolated from the bile of an ox(Froger et al.,2014).The molecular structure of taurine differs from that of amino acids by the presence of a sulfonic acid,instead of the more common carboxylic acid group in the structure of amino acids.