Phenyl Vinyl Sulfone Research Articles

Cobalt(II) catalyzed Michael-type hydroamination of activated olefins

The aza-Michael addition reaction of primary and secondary amines to α,β-unsaturated olefins viz; acrylonitrile, phenyl vinyl sulfone and dimethyl maleate has been carried out using 5–10 mol% Co(NO3)2.6H2O as a catalyst in t-BuOMe at 80–100 °C, giving rise to the desired β-aminocarbonyl compounds or sulfones in moderate to good yields. A wide range of aromatic amines, even those bearing electron withdrawing groups could be added to activated olefins via this strategy. Addition of (hetero)aromatic amines were also feasible, while in case of 2-aminopyridine the reaction was found to be effective only when AgOTf was added along with the catalyst. The aliphatic amines; benzylamine, dibenzylamine, di-n-butylamine were also smoothly added to acrylonitrile and phenyl vinyl sulfone. The methodology describes cobalt(II) nitrate as an eco-friendly, cheap and shelf available catalyst suitable for performing the Michael-type hydroamination reactions.

Catalytic Generation of Benzyl Anions from Aryl Ketones Utilizing [1,2]-Phospha-Brook Rearrangement and Their Application to Synthesis of Tertiary Benzylic Alcohols.

A synthetic method of tertiary alcohols was developed based on the formal umpolung addition of aryl ketones with electrophiles utilizing the [1,2]-phospha-Brook rearrangement under Brønsted base catalysis. The addition reaction of α-hydroxyphosphonates, derived from alkyl aryl- and diaryl ketones, with electrophiles such as phenyl vinyl sulfone, afforded phosphates having a tertiary alkyl group, which were readily convertible to the corresponding tertiary benzylic alcohols. This operationally simple protocol provides efficient complementary access to tertiary alcohols that are difficult to synthesize by conventional methods.

Synthesis of axially chiral biaryls via Pd(II)-catalyzed direct C(sp2)−H olefination

Herein, a protocol for the construction of axially chiral biaryls via Pd-catalyzed direct C–H olefination of 1-arylisoquinoline N-oxides through kinetic resolution have been uncovered. The atroposelective C–H olefination of 1-arylisoquinoline N-oxides is achieved with alkenes such as acrylates, styrenes, phenylvinyl sulfone, acrylonitrile, and maleimides. The commercially available, cost-effective, and bench-stable chiral mono-protected amino acid is successfully utilized as the chiral ligand to achieve atroposelective products via kinetic resolution. The high conformational stability of the axially chiral products observed from the DFT calculations, shows their excellent stability. A plausible mechanism has been proposed based on the preliminary mechanistic studies, which was further evidenced by the DFT calculations.

Thioester-rich degradable copolymers from a thionolactone and S-vinyl and P-vinyl monomers

The recent advent of the radical thiocarbonyl addition–ring-opening (TARO) copolymerization of thionolactones with vinyl monomers enables the production of degradable thioester backbone-functional vinyl copolymers promising for recycling and biomedical applications. To better understand the copolymerization behaviour of the prototypical thionolactone, dibenzo [c,e]oxepin-5(7H)-thione (DOT), copolymers with three S- and P-vinyl comonomers, phenyl vinyl sulfide (PVS), phenyl vinyl sulfone (PVSO), and diethyl vinylphosphonate (DEVP) were prepared through free and RAFT radical polymerizations. In all cases, DOT was incorporated faster than the vinyl comonomers which led to copolymers with up to 89 mol-% DOT content—surprising in light of past reports of significant retardation for high DOT feeds. All copolymers proved readily degradable. A postpolymerization oxidation enabled the conversion of a DOT–PVS copolymer into a corresponding DOT–PVSO species that remained degradable and offered a synthetic strategy to prepare copolymers with compositions not accessible through a direct copolymerization.

Lanthanoids in Hydroarylaminations: Yb(III)- and Tb(III)-Catalyzed Addition of Arylamines to Activated Olefins

AbstractMichael-type hydroaminations of acrylonitrile, phenyl vinyl sulfone, and dimethyl maleate were realized using arylamines catalyzed independently by Yb(OTf)3 and Tb(OTf)3 to give the desired β-aminonitriles, β-amino sulfones, and dimethyl aspartates, respectively, in moderate to excellent yields. The reactions were carried out in toluene for Yb(OTf)3 and in t-BuOMe for Tb(OTf)3, all reactions were performed at 100 °C.

Decatungstate‐Catalyzed Carbon‐Carbon Bond Formation Between Furfural and Electron‐Deficient Olefins

AbstractFurfural is produced on a large commercial scale from lignocellulose and can be used for the preparation of several industrial chemicals with four to five carbon atoms. Further functionalization of furfural by C−H activation, however, is less widely developed. In the present work, tetrabutylammonium decatungstate is investigated as an inexpensive photocatalyst for activating the aldehyde C−H bond and mediate a coupling between furfural and electron‐deficient olefins. The results show that furfural can be successfully added to benzylidene malononitriles, acrylates, itaconic anhydride, maleic anhydride, 2‐vinylpyridine and phenyl vinyl sulfone to generate the corresponding furanyl ketones in moderate‐to‐good yields. The electronic properties of the electron‐deficient olefins are instrumental for achieving a favorable reaction with furfural. The findings show how photocatalysis can be used to form new carbon‐carbon bonds from a platform molecule, which in this way can be converted into a number of more advanced structures.

Accumulation of Re-complex-based Catalytic Centers in Metal–Organic Cages for Photochemical CO2 Reduction/Insertion

Metal–organic cages (MOCs) composed of trinuclear zirconium clusters, Re-complex-based catalyst-incorporated linkers (Lcat), and catalyst-free linkers (L) are synthesized using varying ratios of Lcat and L ([{Cp3Zr3(μ3-O)(μ2-OH)3}4LcatnL6−n]4+ (n = 0.0–5.0, Cp = cyclopentadienyl)). Investigating the catalytic activity of the obtained MOCs revealed that the accumulation of the Re-complex-based catalytic centers affects the photochemical CO2 reduction and CO2 insertion into phenyl vinyl sulfone. Metal-organic cages (MOCs) composed of trinuclear zirconium clusters, Re-complex-based-catalyst-incorporated linkers (Lcat), and catalyst-free linkers (L) were synthesized with various ratios of Lcat and L. The MOCs can serve as catalysts for CO2 reduction and CO2 insertion reactions, and the effect of accumulation of active sites on the photocatalytic activity of MOCs was clarified for the first time.

Electrolyte regulating and interface engineering for high voltage LiCoO2 lithium metal batteries

To achieve higher energy density of lithium ion batteries (LIBs), researchers are developing a new generation of high-voltage (≥4.5 V) LiCoO2 (LCO). Increasing the voltage is accompanied by the decomposition of the electrolyte, successive irreversible phase transitions, and dissolution of transition metals, etc., which are largely benefit from detrimental cathode-electrolyte interface reactions. Here, we construct a stable N, S-rich electrode/electrolyte interphase on both Li anode as well as LCO cathode to solve the above problems through the electrolyte design with the dual additives of acrylonitrile and phenyl vinyl sulfone. Specifically, the uniform N, S-rich cathode/electrolyte interphase (CEI) separates the electrolyte and LCO, and reduces the catalytic decomposition of the electrolyte by Co4+. Moreover, phenyl vinyl sulfone has an excellent compatibility with the Li metal anode due to the in-situ formed LiF-rich solid electrolyte interphase (SEI). With the modification of dual-additives, the LCO lithium metal battery exhibits high-capacity retention about 80 % over 1000 cycles at upper cut-off voltage of 4.5 V and 76 % over 300 cycles at 4.6 V.

TBADT‐Mediated C‐C Bond Formation Exploiting Aryl Aldehydes in a Photochemical Flow Reactor

AbstractA robust and general photochemical process is reported converting various aryl aldehydes into β‐ketonitriles and related species. Tetrabutylammonium decatungstate (TBADT) is used as photocatalyst in combination with a high‐power LED emitting at 365 nm. Standardization and scalability are enabled by using a flow reactor platform integrating the LED light source placed within an encased reactor coil. Under optimized conditions a variety of aromatic and heteroaromatic aldehydes is reacted with acrylonitrile, methyl methacrylate and phenyl vinyl sulfone to give the desired products in high yields, short residence times of 5–30 minutes and a throughput of up to 41 mmol/h. This continuous process overcomes limitations previously encountered for aromatic substrates and represents an effective means to generate a variety of difunctionalized building blocks for further elaborations with an ideal atom economy.

An efficient strategy based on polyelectrolyte of constructing a sequential energy transfer artificial light-harvesting system for photocatalysis

In this work, an efficient artificial light-harvesting system with a two-step sequential energy transfer process was first constructed based on the polyelectrolyte material sodium carboxymethyl cellulose (CMC) and AIE molecule cyano-substituted amphiphilic hydroquinone derivative (PPTA) in an aqueous solution. The energy harvested by the two fluorescent dyes EY and SR101 from the supramolecular assembly PPTA-CMC was fully used for photochemical catalysis for the dehalogenation of α-bromoacetophenone, cross dehydrogenation coupling reaction (CDC), and alkylation of C–H bonds of phenyl vinyl sulfone (PVS) and tetrahydrofuran (THF) in the aqueous medium.

Construction and application of the polyelectrolyte-based sequential artificial light-harvesting system

In this work, we have designed and synthesized a cyano-substituted p-phenylenevinylene derivative (PPTA), which can self-assemble into positively charged nanoparticles in an aqueous solution with a deep green fluorescence. An anionic polyelectrolyte material guar gum modified by carboxylic acid (GP5A) was chosen to build an artificial light-harvesting system (LHS) through self-assembly with PPTA, in which two acceptors Eosin Y (EY) and Nile red (NiR) were loaded into the PPTA-GP5A assemblies through electrostatic interaction and Van der Waals force. By adjusting the molar ratio of PPTA-GP5A/EY at 1:0.004, the one-step artificial LHS can exhibit high energy transfer efficiency (ΦET) (38.9%) and antenna effect (AE) (4.6). Subsequently, with the addition of NiR, the ΦET and AE of the two-step sequential artificial LHS were calculated to be 71.9% and 13.5, respectively. Moreover, the two-step artificial LHS constructed by the polyelectrolyte material GP5A can be used as a nanoreactor to photocatalyst alkylation of C-H bonds of phenyl vinyl sulfone (PVS) and tetrahydrofuran (THF) in water with a yield of 42%. Therefore, we have constructed an artificial LHS with two-step energy transfer based on polyelectrolytes through the electrostatic interaction to improve energy transfer efficiency, which can also be used as a nanoreactor for photocatalysis.

Microfluidics Biocatalysis System Applied for the Synthesis of N-Substituted Benzimidazole Derivatives by Aza-Michael Addition

Benzimidazole scaffolds became an attractive subject due to their broad spectrum of pharmacological activities. In this work, a methodology was developed for the synthesis of N-substituted benzimidazole derivatives from benzimidazoles and α, β-unsaturated compounds (acrylonitriles, acrylate esters, phenyl vinyl sulfone) catalyzed by lipase TL IM from Thermomyces lanuginosus in continuous-flow microreactors. Investigations were conducted on reaction parameters such as solvent, substrate ratio, reaction temperature, reactant donor/acceptor structures, and reaction time. The transformation is promoted by inexpensive and readily available lipase in methanol at 45 °C for 35 min. A wide range of β-amino sulfone, β-amino nitrile, and β-amino carbonyl compounds were efficiently and selectively synthesized in high yields (76–97%). All in all, a microfluidic biocatalysis system was applied to the synthesis of N-substituted benzimidazole derivatives, and could serve as a promising fast synthesis strategy for further research to develop novel and highly potent active drugs.

A Simple and General Nickel‐Catalyzed Michael‐Type Hydroamination of Activated Olefins Using Arylamines

AbstractA simple and general addition of aromatic amines to activated olefins viz; acrylonitrile, phenyl vinyl sulfone and dimethyl maleate were realized using a combination of 1–10 mol% of NiBr2 and 2–20 mol% of AgOTf at 27–100 °C in toluene as solvent. A variety of aromatic amines bearing both electron donating and electron withdrawing groups including sterically demanding ones, as well as heteroaromatic amines could be added to activated olefins giving rise to the desired β‐amino acid derivatives or β‐amino sulfones in good yields. Addition of anilines to acrylonitrile was also found to be progressing when AgOTf alone was used as catalyst but was far less effective when compared to catalysis in the presence of NiBr2.

Design, Synthesis and In Vitro Evaluation of Spirooxindole-Based Phenylsulfonyl Moiety as a Candidate Anti-SAR-CoV-2 and MERS-CoV-2 with the Implementation of Combination Studies.

The search for an effective anti-viral to inhibit COVID-19 is a challenge for the specialized scientific research community. This work investigated the anti-coronavirus activity for spirooxindole-based phenylsulfone cycloadducts in a single and combination protocols. The newly designed anti-SARS-CoV-2 therapeutics spirooxindoles synthesized by [3 + 2] cycloaddition reactions represent an efficient approach. One-pot multicomponent reactions between phenyl vinyl sulfone, substituted isatins, and amines afforded highly stereoselective anti-SARS-CoV-2 therapeutics spirooxindoles with three stereogenic centers. Herein, the newly synthesized spirooxindoles were assessed individually against the highly pathogenic human coronaviruses and proved to be highly potent and safer. Interestingly, the synergistic effect by combining the potent, tested spirooxindoles resulted in an improved antiviral activity as well as better host-cell safety. Compounds 4i and 4d represented the most potent activity against MERS-CoV with IC50 values of 11 and 23 µM, respectively. Both compounds 4c and 4e showed equipotent activity with the best IC50 against SARS-CoV-2 with values of 17 and 18 µM, respectively, then compounds 4d and 4k with IC50 values of 24 and 27 µM, respectively. Then, our attention oriented to perform a combination protocol as anti-SARS-CoV-2 for the best compounds with a different binding mode and accompanied with different pharmacophores. Combination of compound 4k with 4c and combination of compounds 4k with 4i proved to be more active and safer. Compounds 4k with 4i displayed IC50 = 3.275 µM and half maximal cytotoxic-concentration CC50 = 11832 µM. MD simulation of the most potential compounds as well as in silico ADMET properties were investigated. This study highlights the potential drug-like properties of spirooxindoles as a cocktail anti-coronavirus protocol.

Design, synthesis and biological evaluation of phenyl vinyl sulfone based NLRP3 inflammasome inhibitors

As the vital component of innate immune system, the NLRP3 inflammasome is implicated in the onset and progression of a variety of inflammatory diseases and has emerged as an attractive drug target. Herein a series of novel phenyl vinyl sulfone based NLRP3 inflammasome inhibitors were designed, synthesized and biologically characterized. The most potent two hits 7a and 5b showed inhibition on the NLRP3 inflammasome with the IC50 of 1.83 ± 0.28 µM and 0.91 ± 0.06 µM, respectively. Further characterization confirmed their inhibition of NLRP3-mediated IL-1β release in vivo. Collectively, our findings encourage further research of more potent inhibitors based on this chemical scaffold.

Borinic Acid Catalyzed Regioselective N-Alkylation of Azoles.

A method for regioselective N-alkylation of ambident, azole-type heterocycles with alkene or epoxide electrophiles is described. In the presence of diphenylborinic acid (Ph2BOH) and an amine cocatalyst, heterocyclic nucleophiles such as 1,2,3- and 1,2,4-triazoles, substituted tetrazoles, and purine are activated toward selective N-functionalization. The scope of electrophilic partners includes enones, 2-vinylpyridine, phenyl vinyl sulfone, a dehydroalanine derivative, and epoxides. Mechanistic studies, including in situ 11B NMR spectroscopy and kinetic analysis, are discussed.

Bifunctional additive phenyl vinyl sulfone for boosting cyclability of lithium metal batteries

One of the bottlenecks limiting the cycling stability of high voltage lithium metal batteries (LMBs) is the lack of suitable electrolytes. Herein, phenyl vinyl sulfone (PVS) is proposed as a multifunctional additive to stabilize both cathode and anode interfaces as it can be preferentially oxidized/reduced on the electrode surfaces. The PVS derived solid electrolyte interphase films can not only reduce the transition metal dissolution on the cathode side, but also suppress the Li dendrite spread on the lithium anode side. The Li||Li symmetric battery with PVS addition delivers longer cycle life and a higher critical current density of over 3.0 mAh cm−2. The LiNi0.8Co0.1Mn0.1O2 (NCM811)||Li full cell exhibits excellent capacity retention of 80.8% or 80.0% after 400 cycles at 0.5 C or 1 C rate with the voltage range of 3.0–4.3 V. In particular, the NCM811||Li cell under constrained conditions remains operation over 150 cycles. This work offers new insights into the electrolyte formulations for the next generation of LMBs.

Metal-Organic Framework-Encapsulated Anthraquinone for Efficient Photocatalytic Hydrogen Atom Transfer.

Anthraquinone (AQ) as an effective hydrogen atom transfer catalyst was limited in photocatalysis application due to the dimerization of reduced AQ. Sr-NDI@AQ, encapsulating AQ into the channel of Sr-NDI, paved a new way for solving the problem of dimerization of reduced AQ and improving the catalytic efficiency owing to the fast electron transfer from reduced AQ to the ligand through host-guest interaction. The structure of Sr-NDI@AQ was determined by single-crystal X-ray diffraction, and the value for distance and torsion angle between the ligand and AQ was calculated. The photochemical and electrochemical properties for Sr-NDI@AQ were characterized through a series of experiments. The coupling reaction between aldehyde and phenyl vinyl sulfone and photoacetalization reaction were carried out, displaying the improving catalytic efficiency of Sr-NDI@AQ compared to Sr-NDI and AQ. The reaction mechanisms were proposed through radical capture and electron paramagnetic resonance experiments.

Pd‐Catalyzed Atropselective C−H Olefination Promoted by a Transient Directing Group

AbstractA Pd(II)‐catalyzed atropselective olefination of biaryls with maleimides is reported using chiral transient directing group (CTDG) strategy L‐tert‐leucine is used as a chiral auxiliary to obtain atropselective biaryl aldehydes with enantiomeric excess ranging from 70 to 99%. The method is also applicable for other olefins such as acrylonitrile, phenyl vinyl sulfone, and N‐tert‐butyl acrylamide, providing corresponding atropselective biaryl aldehydes with 97–99% ee. Non‐linear effect studies suggest that chiral auxiliary is responsible for the atropselectivity of products. Other studies suggested the critical role of reaction time on yield and s‐factor of desired products.magnified image

Photocatalytic C-H Activation with Alcohol as a Hydrogen Atom Transfer Agent in a 9-Fluorenone Based Metal-Organic Framework.

Hydrogen atom transfer (HAT) has become an attractive strategy for the activation of hydrocarbon feedstocks. Alcohols, as inexpensive and efficient hydrogen transfer reagents, have limited application in C-H functionalization due to the difficulty in the alkoxy radical acquisition. 9-Fluorenone moieties were incorporated into the metal-organic framework (MOF) as a photocatalyst; through the formation of hydrogen bonds between the carbonyl group of a ligand and alcohol, alkoxy radicals could be obtained by the visible-light-driven oxidation of 2,2,2-trichloroethanol via proton-coupled electron transfer (PCET). Effectively photocatalyzed intermolecular coupling reactions between phenyl vinyl sulfone and aldehyde or cyclic ether were realized through the HAT pathway. Compared to homogeneous catalysts, the heterogeneous MOF photocatalyst improved the catalytic efficiency and could be recycled at least five times. The microenvironment of the Zn-OFDC channel was beneficial for the formation of hydrogen bonds and stability of alkoxy radicals.