AN EFFICIENT SYNTHESIS OF PROPARGYLIC PHOSPHONIUM SALTS

Alkylated propargyl bromides react with phosphiaes in acidic tetrahydrofuran solution to give propargylic phosphonium salts in good yield.

ANTIBACTERIAL ACTIVITY OF SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS GRAFTED ON "GEL-TYPE" STYRENE-DIVINYLBENZENE COPOLYMERS

A systematic study on the synthesis and antibacterial activity of the quaternary "onium" salts grafted on an insoluble "gel-type" styrene-7% divinylbenzene copolymer by polymer-analogous reactions is showed. Antibacterial activity of quaternary ammonium and/or phosphonium salts grafted on polymer-supports has been studied against Staphylococcus aureus and Escherichia coli. A wide variety of "onium" salts bound to macromolecular supports with different quaternary groups and different quaternary chain length substituents were examined. The antibacterial activity of mixed "onium" salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support.

Transformation of carbon dioxide into valuable chemicals over bifunctional metallosalen catalysts bearing quaternary phosphonium salts

The chemical transformation of CO2under mild conditions remains a great challenge because of itsexceptional kinetic and thermodynamic stability.Two important reactions in the transformation ofCO2are the N‐formylation reaction of amines using hydrosilanes and CO2,and the cycloaddition ofCO2to epoxides.Here,we report the high efficiency of bifunctional metallosalen complexes bearingquaternary phosphonium salts in catalyzing both of these reactions under solvent‐free,mild conditionswithout the need for co‐catalysts.The catalysts’bifunctionality is attributed to an intramolecularcooperative process between the metal center and the halogen anion.Depending on the reaction,this activates CO2by permitting either the synergistic activation of Si–H bond via metal–hydrogen coordinative bond(M–H)or the dual activation of epoxide via metal–oxygen coordinativebond(M–O).The one‐component catalysts are also shown to be easily recovered and reusedfive times without significant loss of activity or selectivity.The current results are combined withprevious work in the area to propose the relevant reaction mechanisms.

Synthesis and Antibacterial Performance of Quaternary Phosphonium Salts with Reactive Hydroxyl Group

Quaternary phosphonium salts （QPS） with reactive groups used as antibacterial agents are promising which could be covalently linked to inert polymer surfaces by in situ polymerization. In this work, two kinds of quaternary phosphonium salts with hydroxyl groups were synthesized successfully. Characterization of these two quaternary phosphonium salts was performed by the Fourier transform infrared spectroscopy （FT-IR） and nuclear magnetic resonance （NMR） spectrometry. The thermal stability and antibacterial activity of antibacterial agents were also investigated by using thermo-gravimetric analysis, differential scanning calorimetry （TG-DSC） and agar diffusion method. The test results showed that these two QPS exhibited good thermal stability and excellent antibacterial activity against both bacteria： Staphylococcus aureus and Escherichia coll.

POLYMER-SUPPORTED SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS AS CATALYSTS FOR PHASE-TRANSFER REACTIONS

In this study was to investigate, by phase-transfer catalysis, the activity of single and mixed ammonium and phosphonium salts grafted on a 揼el-type?styrene-7% divinylbenzene copolymer in the oxidation of benzyl alcohol with hydrogen peroxide. A wide variety of catalysts with different quaternary groups and different quaternary chain length substituents were examined. The activity of single 搊nium?salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support. The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the onium and of the functionalization degree with phosphonium groups.

Charge transfer complex enabled photoreduction of ether phosphonium salts for the selective oxyalkylation of enamides

A charge transfer complex(CTC)-enabled photoreduction of ether phosphonium salts for the generation of oxyalkyl radicals was described.The photoreduction provides a convenient method to achieve selective oxyalkylation of enamides with broad substrate scope.The method features operational simplicity,mild and inherent green conditions.

Synthesis and Reactivity of Trifluoromethylthiophosphonium Salts

This article described an unprecedented synthesis of trifluoromethylthiophosphonium salts from allyl trifluoromethyl sulfoxide and phosphines in the presence of trimethylsilyl trifluoromethanesulfonate(TMSOTf)through Mislow-Evans-type rearrangement.The resulting trifluoromethylthiophosphonium salts were firstly isolated and fully characterized.These fluoroalkylphosphonium salts,as exemplified by trifluoromethylthio triphenylphosphonium salt(6a),exhibited unique and versatile reaction with nucleophiles and deoxygenative trifluoromethylthiolation reaction of carboxylic acids.Furthermore,the photoredox catalytic tunable radical hydrotrifluoromethylation and hydrotrifluoromethythiolation of unactivated alkenes with 6a was successfully.

Novel Stereoselective Synthesis of (E)-a,b-Unsaturated Esters by the Tandem Reaction of Deprotonation-Oxidation-Wittig Reaction from Phosphonium and Arsonium Salt

Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide, which affords a general simplified method for the stereoselective synthesis of (E)- a, b-unsaturated esters 3.

Synthesis,Structure and Properties of a Novel Nickel(Ⅱ) Chloride Complex Supported by Phosphine Ligands

The C-C1 bond of N-（2-chlorophenyl）acetamide （1） was successfully activated by tetrakis（trimethylphosphine）nickel（0）. The four-coordinate nickel（II） chloride complex trans- [（C6H4NHC（=O）Me）Ni（PMe3）2CI] （2） as a C--CI bond activation product was obtained without coordination of the amide group. Phosphonium salt CI[Me3P＋-ortho-C6H4NHC（=O）Me] （3） was isolated by reacting complex 2 as a starting material under 1 bar of CO at room temperature. The molecular and crystal structures of 2 were determined by single-crystal X-ray diffraction.

Highly stereoselective construction of polycyclic benzofused tropane scaffolds and their latent bioactivities: bifunctional phosphonium salt-enabled cyclodearomatization process

Structurally fused heterocycles encompassing a centerpiece of benzotropane are significant scaffolds with a plethora of promising biological activities,but such molecular architectures pose a long-standing daunting synthetic challenge.Herein,we reported a highly efficient asymmetric cyclodearomatization of 2-nitrobenzofurans with cyclic azomethine ylides by employing bifunctional phosphonium salts as phase-transfer catalysts.Under optimized reaction conditions,a diverse array of polycyclic benzofused tropane derivatives with four contiguous 4°/3°stereocenters were readily synthesized in both high yields and diastereoselectivities with up to>99%ee.The practicality and utility of this protocol were further demonstrated by the scaled-up reaction and facile elaborations.Moreover,preliminary investigations into their antitumor activities were also presented.

Functionalized COFs with Quaternary Phosphonium Salt for Versatilely Catalyzing Chemical Transformations of CO_(2)

Currently,it encounters great challenges to accomplish catalyzing various kinds of carbon dioxide(CO_(2))conversion reactions efficiently with single catalyst,let alone control the interplay among catalytic efficiency and selectivity evenly.Here,we prepared a functional covalent organic framework,[PTPP]X%-TD-COF[PTPP=3-bromopropyltriphenylphosphonium;TD=1,3,5-tri(4-aminophenyl)benzene-1,4-diformylbenzene],by immobilizing the quaternary phosphonium salt onto the skeleton of COFs through a post-synthesis strategy for versatilely catalyzing reduction of CO_(2) and CO_(2) fixation on epoxide and aziridine facilely.With the typical features of COFs(such as porosity and ordered structure)and catalytic activity of the quaternary phosphonium salt,[PTPP]X%-TD-COF possesses an intensely synergistic effect for catalyzing the chemical transformations of CO_(2).Noteworthily,the quaternary phosphonium salt functionalized COFs catalyze the CO_(2) reduction reaction with amine and phenylsilane to produce formylated and methylated products under gentle reaction conditions with high selectivity and efficiency.Furthermore,[PTPP]_(X%)-TD-COF shows high catalytic ability in CO_(2) chemical fixation reactions.

A facile preparation of a novel nonleaching antimicrobial waterborne polyurethane leather coating functionalized by quaternary phosphonium salt

The aim of this research is to develop a novel non-leaching antimicrobial waterborne polyurethane(WPU)leather coating material with covalently attached quaternary phosphonium salt(QPS).The structure of the QPS-bearing WPU has been identified,and their thermal stability,mechanical property,and antimicrobial performance have been investigated.The results reveal that the incorporation of QPS slightly reduces the thermal stability of WPU material but would not affects its usability as leather coating.Despite the presence of hydrophobic benzene in QPS structure,the strong hydration of its cationic groups leads to the increased surface contact angle(SCA)and water absorption rate(WAR)of the films,suggesting that the water resistance of the films needs to be improved for the purpose of leather coatings.Antibacterial tests demonstrate that when the QPS content is 20 wt%,QPS-bearing WPU shows effective antimicrobial activity against bacteria.The WPU containing QPS prepared in this study is a non-leaching antimicrobial material and has great potential application as leather coating.

Access to Enantioenriched Allylic Alcohols via Peptide-Mimic Phosphonium Salt-Catalyzed Asymmetric Aerobic Hydroxylation

The development of catalytic asymmetric methods that enable access to value-added functionalities or structures,exemplified by allylic alcohols,is a highly interesting yet challenging topic from both academic and industrial perspectives.However,before recent advances in chemical catalysis,there were scarce protocols toward constructing enantioenriched tertiary allylic alcohol scaffolds.In this context,peptide-mimic phosphonium salts were found to be highly efficient in catalytic asymmetricα-hydroxylation ofα,β-unsaturated and/orβ,Y-unsaturated compounds with satisfactory regio-and stereochemical outcomes(up to 97%yield and 95%ee).This methodology tolerates a broad array of substrates and thus provides an expeditious and unified platform for the assembly of enantioenriched tertiary allylic alcohols by avoiding the use of additional reductants and expensive metal catalysts.Furthermore,the power of this protocol is enlarged by simple conditions and the use of air as a source of hydroxyl functionality.

Antibacterial performance of cationic quaternary phosphonium-modified chitosan polymer in water

Microbial contamination in water has emerged as a critical concern and thus developing biocide materials for controlling microbial contamination is crucial.Removing all pathogenic bacteria in water is difficult when using traditional water treatment technologies.Moreover,these bacteria can easily reproduce during pipeline distribution.In this work,a facile and effective chitosan derivative biocide denoted as PCC was developed by grafting with quaternary phosphonium salt(QPS).PCC became positively charged with a wide range of p H and demonstrated antibacterial activity up to 95%and 100%against Escherichia coli and Staphylococcus aureus as model pathogens,respectively.The grafting of QPS may disrupt the cell membrane and lead to bacterial inactivation,as demonstrated by the scanning electron microscopy image and the concentration of intracellular substance leakage.MTT assay results indicate that PCC achieved good biocompatibility with negligible in vitro cytotoxicity.These findings introduce a promising approach for bacterial decontamination due to its low cytotoxicity and high biocidal activity.

Stereodivergently asymmetric synthesis of chiral phosphorus compounds by synergistic combination of ion-pair catalyst and base

Stereodivergently constructing the designed products having adjacent multi-stereocenters via a given reaction,with excellent control of both absolute and relative configurations,presents one of the substantial hurdles in asymmetric catalysis.Herein,we report a precisely stereodivergent asymmetric protocol by synergistic combination of phosphonium-involved ion-pair catalysis and base for accessing to chiral phosphorus compounds bearing two adjacent chiral centers particularly containing an acidic protonated enantioenriched carbon atom,having broad functional group compatibility in both dynamic and thermodynamic processes under mild reaction conditions.Two keys for the success in constructing these stereoisomers with high levels of regio-,diastereo-,and enantioselectivities were contained:firstly,the precise stereo-control in providing dynamic products was enabled by bifunctional phosphonium salt catalyst with semi-enclosed cavity;secondly,the readily stereospecific transformation of adducts from dynamic to thermodynamic version was initiated by achiral base.All four stereoisomers could be readily accessed even in gram-scale in high yields with maintaining excellent stereoselectivities,illustrating the potential of this synergistic catalytic methodology in organic synthesis.Moreover,mechanistic studies including density functional theory(DFT)calculations and control experiments provide insights into the mechanism.

Tandem Reaction of Deprotonation-Oxidation-Wittig Reaction: Stereoselective Synthesis of (E)-α,β-Unsaturated Enoates

Phosphonium or arsonium salt with primary alcohol can undergo the tandem reaction of deprotonation-oxidation-Wittig reaction in the presence of sodium hydroxide and manganese dioxide, providing a general and efficient method for the stereoselective synthesis of (E) -α, β-unsaturated enoates.