Amine Type Research Articles

Aggregation-Induced Emission Nanoparticles for Single Near-Infrared Light-Triggered Photodynamic and Photothermal Antibacterial Therapy.

Phototheranostics is a potential area for precision medicine, which has received increasing attention for antibacterial applications. Integrating all phototheranostic modalities in a single molecule and achieving precise spatial colocalization is a challenging task because of the complexity of energy dissipation and molecular design. Here, a type of quaternary amine functionalized aggregation-induced emission (AIE), AIEgen, was synthesized and used to produce singlet oxygen (1O2) and heat, which were used to eradicate the bacteria. With the introduction of the positive charge in AIEgen, AIE nanoparticles (AIE NPs) could selectively target bacteria. Notably, the AIE NPs displayed obvious antibacterial performance against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The antibacterial rates of AIE NPs were as high as 99.9% and 99.8% for S. aureus and E. coli, respectively. Therefore, our results suggested the potential of AIE NPs acting as broad-spectrum antimicrobial materials, which provided a strategy for treating different microorganisms.

Adhesive and Impact-Peel Strength Improvement of Epoxy Resins Modified with Mono and Diamine Functionalized Elastomers

Epoxy resins are widely applied in the automotive and electronic industries. However, pure epoxy resins are brittle and thus possess poor mechanical properties. Herein, we report a facile method for improving the impact-peel and adhesive strengths of epoxy resins via the incorporation of two different types of polyether amines (monoamine-based and diamine-based prepolymers). A comparative study was performed to investigate the potential advantages of incorporating a prepolymer into an epoxy resin matrix. It was discovered that the incorporation of a diamine prepolymer significantly improved the impact-peel strength of the epoxy resin system at low (-40°C) and room (23°C) temperatures. For 15 wt% adhesive loading, the diamine prepolymer-based epoxy system demonstrated a 130% (low temperature) and 32% (room temperature) higher impact-peel strength than the monoamine prepolymer-based epoxy system. Moreover, the 15 wt% diamine prepolymer-based epoxy system exhibited a significantly improved shear strength (~36 MPa) and T-peel strength (260 N/25 mm) owing to the effectively reduced crack propagation and cohesive interactions between the epoxy molecules. Our results suggest that the modification of epoxy resins with an appropriate amount of mono and diamine-functionalized elastomers provides a novel route for the development of highly efficient adhesive materials for various applications.

Design, Synthesis of Mannich Bases Derivatives of Thiosemicarbazide and their Evaluation for Anticancer Activity using Potato Disk Bioassay Method

Mannich bases and thiosemicarbazide individually are known to show verity of pharmacological activities such as anti-inflammatory, anticancer, antifilarial, antibacterial, antifungal, anticonvulsant, anthelmintic, antitubercular, analgesic, anti-HIV, antimalarial, antipsychotic, antiviral and so forth. As novel attempt in present work in first step synthesis of verity of mannich bases is done using structurally different types of aldehyde, ketones and amines. The condensation of synthesized mannich bases is done with thiosemicarbazide to form a novel class of compounds called mannich bases of thiosemicarbazide. Use of bioassay is one of the ways of carrying out preliminary investigation of activity. A. tumefaciens induced potato disc tumor assay has been used to investigate anticancer activity of synthesized compounds. The compounds B2, B4, B25, B26, B28, B29 and B30 have shown same or better inhibitory activity compared to Gemcitabine used as standard.

Facile Carbamic Acid Intermediate Formation in Aqueous Monoethanolamine and Its Vital Role in CO2 Capture Processes

Monoethanolamine (MEA) is the most studied and used to be considered as benchmark solvent for CO2 capture. CO2 absorption in aqueous MEA is well known to produce ion pairs such as carbamate (MEACOO–) and protonated amine (MEAH+), following a stepwise reaction mechanism involving a zwitterionic intermediate (MEA+COO–). Contrastingly, thermal degradation of MEA has been thought to occur through carbamic acid (MEACOOH) formation under stripper conditions. This raises a fundamental question regarding the MEACOOH formation mechanism and its relative concentration in CO2-loaded aqueous MEA. Using ab initio molecular dynamics and metadynamics simulations, we have determined probable routes and free-energy barriers for proton transfer reactions associated with the MEA+COO– ↔ MEACOO–/MEAH+ conversion. Our results clearly demonstrate that the lowest free-energy path involves MEACOOH formation in a 30 wt % MEA solution. A zero-dimensional model based on the predicted energetics illustrates that the concentration ratio of MEACOOH to MEACOO– increases with CO2 loading and temperature; the estimated ratio reaches up to 25% at high CO2 loadings (∼0.5) and high stripping temperatures (∼413 K). While carbamic acid formation tends to be a function of amine type, the quantitative understanding helps explain experimental observations and also greatly assists in designing amine-based solvents that have enhanced resistance to thermal degradation.

High-sensitivity sensor array base on molecular design and machine learning for amine differentiation in exhaled vapor

• A sensor array which can classify pathological biomarkers of amines is provided. • By molecular backbone rigidity together with multiple hydrogen-bonding acceptor and aromatic terminal structure tuning, the difference interactions between molecules and multiple amines are realized. • Through molecular design and machine learning, the detection and recognition of ppb concentration of amine/ammonia at room temperature with an accuracy of 90% by the sensor array are achieved. Nowadays, the studies on the diagnosis of diseases by exhaled gas mostly focus on single markers. In fact, there are biomarkers with similar properties but corresponding to different diseases. The present sensing techniques still cannot achieve the multi-label classification of the targets simultaneously. Through introducing multiple hydrogen bond receptors and adjusting of the aromatic ring end group, the interaction strength modulation between target molecules and sensor array was realized. The sensor responses related to molecular structure can be used as the characteristic of the detection. By the machine learning, the different types of amines are well identified. It is worth mentioning that this method can also distinguish mixed amines ranging any concentration in ppm-ppb, which can be used in breath analyzer. The recognition of the mixed ammonia / amine gases is achieved at room temperature with an accuracy of 90%. The combination of molecular design and machine learning strategy can improve the selectivity of sensor array, which also provides a new idea for the design of sensor array that can be used in rapid, convenient, non-invasive and cost-effective exhalation diagnosis.

Adhesive Films Based on Benzoxazine Resins and the Photoreactive Epoxyacrylate Copolymer

UV-cross-linkable and thermally curable self-adhesive structural tapes (SATs) were compounded using solid commercial benzoxazine resins (Araldite MT 35700 and Araldite MT 35910) and a photoreactive epoxyacrylate copolymer (EAC). As initiators of benzoxazine resin polymerization and epoxy component cationic polymerization, two kinds of latent curing agents (LCAs) were tested, i.e., amine type and ionic liquid type. The influence of the benzoxazine resin and the LCA type on the UV-cross-linking process, the self-adhesive features and thermal curing behavior of UV-cross-linked tapes, as well as the shear strength of cured aluminum/SAT/aluminum joints and thermal stability of adhesives were investigated. It was found that the amine additive and the benzoxazine resin take part in the UV-cross-linking process of the EAC as hydrogen donors, which is confirmed by an increase in cohesion (+86%) and a decrease in adhesion (−25%) of SATs. The highest results of adhesion to steel (47 N/25 mm) and overlap shear strength (11.1 MPa) values were registered for SATs based on Araldite MT 35910 and contained 7.5 wt. parts of the amine-type hardener. The formation of a polyacrylate-benzoxazine network has a significant impact on the course of the thermal curing process and the thermomechanical properties of adhesive joints, which was also confirmed by the Cure Index calculation.

Ultrasensitive N-Channel Graphene Gas Sensors by Nondestructive Molecular Doping.

Sensitive and selective detection of target gases is the ultimate goal for commercialization of graphene gas sensors. Here, ultrasensitive n-channel graphene gas sensors were developed by using n-doped graphene with ethylene amines. The exposure of the n-doped graphene to oxidizing gases such as NO2 leads to a current decrease that depends strongly on the number of amine functional groups in various types of ethylene amines. Graphene doped with diethylenetriamine (DETA) exhibits the highest response, recovery, and long-term sensing stability to NO2, with an average detection limit of 0.83 parts per quadrillion (ppq, 10-15), due to the attractive electrostatic interaction between electron-rich graphene and electron-deficient NO2. Our first-principles calculation supported a preferential adsorption of NO2 on n-doped graphene. In addition, gas molecules on the n-channel graphene provide charged impurities, thereby intensifying the current decrease for an excellent response to oxidizing gases such as NO2 or SO2. On the contrary, absence of such a strong interaction between NH3 and DETA-doped graphene and combined effects of current increase by n-doping and mobility decrease by charged impurities result in a completely no response to NH3. Because the n-channel is easily induced by a top-molecular dopant, a flexible graphene sensor with outstanding NO2 detection capability was successfully fabricated on plastic without vertical stacks of gate-electrode and gate-dielectric. Our gate-free graphene gas sensors enabled by nondestructive molecular n-doping could be used for the selective detection of subppq-level NO2 in a gas mixture with reducing gases.

Tri-probe fluorescent sensor array for a wide concentration range and high precision identification of aqueous organic amines

Aqueous organic amines are threatening to organisms and ecosystem balance. Although many techniques have been used for detection, the simultaneous identification of both its type and concentration is still challenging due to its structural similarity and low environmental concentration. Sensor array is a powerful sensing technology to identify analytes via unique fingerprint patterns. However, the information from general sensor array based on the weak interaction limited its discernibility ability to similar substances. Here, we propose to design molecules with various sensing units based on strong interactions and hence rich spectral change, then construct a tri-probe sensor array for efficient fluorescent differentiation of aqueous organic amine. Different fluorescence responses to different concentrations and types of organic amines were produced by this array. Varied interaction between the probes and the amines was proved by NMR spectra analysis. The combination of probes can produce rich and complementary fluorescence changes. These unique fluorescence response patterns can be well identified and processed using hierarchical analysis (HCA) and linear discriminant analysis (LDA), enabling the 99.35% accurate differentiation of 5 concentration orders (1 μM ~ 10 mM) of 6 kinds of amines. Blind detections for samples of diethylamine, diisopropylamine in tap water and propylamine, hexylamine, trimethylamine, triethylamine in other five domestic wastewater all can be classified and distinguished successfully. The influence of temperature, pH and mental ions are also considered. This sensing method, with the feature of facile preparation, fast response, and excellent discrimination accuracy, can provide a potential option for fast quality test of water.

Feasibility and mechanism of an amine-looping process for efficient CO2 mineralization using alkaline ashes

• Amines significantly improved the CO 2 sequestration capacity of ashes. • Amines enhanced Ca 2+ leaching from alkaline ashes. • The phytotoxicity of alkaline ashes were significantly reduced after carbonation. Amine-looping-based CO 2 mineralization is a promising technology for simultaneous CO 2 absorption, mineralization, and carbonate crystallization in a single step. This paper performed a detailed investigation of the feasibility and underlying mechanism of the amine-looping process using industrial alkaline solid wastes, including one Biomass ash (BA) and two coal-fired fly ashes named FA1 and FA2. The CO 2 sequestration capacity and CO 2 removal efficiency of selected ashes were investigated in five typical amine solutions, including monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), 2-amino-2-methy-1-propanol (AMP), and piperazine (PZ). The physicochemical property of ashes before and after carbonation and the dissolution of alkaline minerals in various amine solutions were systematically determined to explore the underlying mechanism involved in the amine-looping process. Results show that greater improvement in CO 2 removal efficiencies and CO 2 sequestration capacities were obtained by selected ashes in amine solutions compared to the traditional CO 2 mineralization in the water-ash-CO 2 system. It also revealed that amines played important roles in promoting CO 2 mass transfer, enhancing Ca 2+ leaching, and producing small-sized CaCO 3 . The largest CO 2 sequestration capacity (102.9 g/kg) was achieved by FA1 in PZ solution which was suggested as the preferred solvent for the amine-looping process. In addition, the environmental risk of carbonated ashes for agricultural application in terms of amine loss and phytotoxicity was evaluated. Results implied that the phytotoxicity of carbonated BA could be neglected when a simple centrifugal wash was used to remove the absorbed amine on the surface of carbonated BA whilst the phytotoxicity of selected ashes can be significantly reduced after carbonation reactions.

Effect of amine type on acidic toxic gas adsorption at ambient conditions on modified CuBTC

Two amine-modified copper-based Metal Organic Frameworks (MOF (CuBTC)) of different surface chemical and textural features were synthesized and used as adsorbents of acidic toxic gases (NO2 and H2S) in both moist (71% relative humidity (R.H.)) and dry conditions. The initial and exhausted samples were characterized by nitrogen adsorption, powder X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis and Fourier transform infrared spectroscopy. The addition of melamine prevented full growth of CuBTC crystals and resulted in amorphous-like particles with sizes less than 200 nm. The material was non-porous with a small surface area. When urea was used as an amine source, the resulting particles maintained the overall octahedral shape of the parent CuBTC MOF and the material was more porous than the parent MOF. While the urea-modified CuBTC sample performed well as an NO2 adsorbent in the presence of moisture, the reactivity of the melamine-modified sample and its physical properties provided a favorable environment for the removal of H2S. The incorporation of amines into the MOF structure also resulted in surface defects /open copper sites that favored the removal of toxic gases in dry conditions. The reactivity of the adsorbents with toxic gases was demonstrated by the changes in the adsorbent colors, in texture, and in surface chemistry (organic salts, complexes, sulfides and nitrates were formed).

Cationic copolymers that enhance wild-type-specific suppression in BNA-clamp PCR and preferentially increase the Tm of fully matched complementary DNA and BNA strands

Mutation detection is of major interest in molecular diagnostics, especially in the field of oncology. However, detection can be challenging as mutant alleles often coexist with excess copies of wild-type alleles. Bridged nucleic acid (BNA)-clamp PCR circumvents this challenge by preferentially suppressing the amplification of wild-type alleles and enriching rare mutant alleles. In this study, we screened cationic copolymers containing nonionic and anionic repeat units for their ability to (i) increase the Tm of double-stranded DNA, (ii) avoid PCR inhibition, and (iii) enhance the suppression of wild-type amplification in BNA-clamp PCR to detect the KRAS G13D mutation. The selected copolymers that met these criteria consisted of four types of amines and anionic and/or nonionic units. In BNA-clamp PCR, these copolymers increased the threshold cycle (Ct) of the wild-type allele only and enabled mutation detection from templates with a 0.01% mutant-to-wild-type ratio. Melting curve analysis with 11-mer DNA–DNA or BNA–DNA complementary strands showed that these copolymers preferentially increased the Tm of perfectly matched strands over strands containing 1-bp mismatches. These results suggested that these copolymers preferentially stabilize perfectly matched DNA and BNA strands and thereby enhance rare mutant detection in BNA-clamp PCR.

Effect of the array of amines on the transfection efficiency of cationic peptidomimetic lipid molecules into neural cells.

The amino groups in the head group of a cationic lipid play a determinative role regarding the nucleic acid delivery efficiency of the LNP formulated from lipids. Herein, we designed four types of lipid bearing different amine-containing branched head groups to investigate the influence of type and number of amines on the neural cell targeted nuclei acid delivery. Conjugation of an ethylamino group at selected positions of a lysine-based cationic lipid resulted in 4 distinct lipids with 3 (denoted N3 lipid), 4 (denoted N4 lipid), 5 (denoted N5 lipid) and 6 (denoted N6 lipid) amino groups, respectively. Comparative analysis by flow cytometry revealed that the N3 lipid had the highest nucleic acid (plasmid and siRNA) transfection efficiency to neural cell lines (BV2 cells and N2a cells). Furthermore, the N3 lipid mediated delivery of siRNA against Toll Like Receptor 4 (TLR4) into oxygen glucose deprivation (OGD)-treated BV2 cells resulted in remarkable silencing of TLR4, inducing alternative polarization (M2) of the cells. Collectively, our data suggest that the N3 lipid is a promising siRNA delivery agent in neural cells.

REDUCING THE AGGREGATIVE STABILITY OF EMULSION STYRENE BUTADIENE RUBBER WITH THE USE OF AROMATIC AMINES

In this paper, for the first time, a study was conducted on the use of various types of aro-matic amines in the production of emulsion rubbers to reduce the aggregative stability of latex dispersions. The use of aromatic hydrocarbons containing amine groupsin the technology of sep-aration of rubber from latex makes it possible to obtain emulsion rubbers at low costs of the coag-ulating agent. It was found that the temperature regime of the coagulation process of the latex system has a significant effect on the consumption of aromatic amines used: the lowest consump-tion was noted when using them to reduce the aggregate stability of latex systems at temperatures not exceeding 20 °C. The consumption of the acidifying agent -15 kg/t of rubber. Low amounts of coagulating agent create good prerequisites for the implementation of a closed technological cycle on an industrial scale, reducing water consumption by rubber extraction workshops from latex, which ultimately increases the environmental friendliness of the entire technological process of their production. The analysis of rubbers as well as the physical and mechanical characteristics of vulcanizates prepared on their basis, showed that the main properties of rubber-technical products, from control and experimental samplescomply with the regulatory requirements of GOST and TU.

Synthesis and biological evaluation of some novel hetroaryl quinolinone derivatives

AbstractThe aim of this study involves the synthesis of novel heterocyclic scaffolds containing quinoline moiety and studying their role as antimicrobial agents. 4‐hydroxy‐6‐phenyl‐2H‐pyrano[3,2‐c]quinoline‐2,5(6H))‐dione (1) was utilized as a precursor for the construction of new polyheterocyclic ring systems. It reacted with three aryl and (heteroaryl) aldehydes to furnish the corresponding arylidenes 2a‐c. The nucleophilic cyclization of compound 2 with hydrazine hydrate to give pyrazolyl quinolinone 3. Moreover, the reaction of 1 with HCHO/morpholine led to the formation of the adduct 7. The synthesized N‐(5–3‐formyl‐4‐hydroxy‐6‐phenyl‐2,5‐dioxo‐5,6‐dihydro‐2H‐pyrano [3,2‐c] quinoline (10) was utilized for the synthesis of 3‐(([aryl]amino)methylene)‐6‐phenyl‐2H‐pyrano[3,2‐c]quinoline‐2,4,5 (3H,6H)‐trione 11a‐c via its treatment with three types of amines. Treatment of 1 with POCl3/Et3N afforded the corresponding 4‐chloro derivative 20. Which upon treatment with thiourea lead to the formation of the corresponding 4‐mercapto derivative 21. The latter 21 was alkylated using ethylbromo acetate giving 22. All freshly synthesized scaffolds were elucidated by considering the data of both elemental and spectral analyses. The synthesized scaffolds were screened for antimicrobial activities also showed promising results. The p‐chlorobenzylidene pyrazolylquinolone derivative 3 has excellent antimicrobial properties against Proteus vulgaris compared to its mild activity against Staph aureus. While 4‐Chloro‐6‐phenyl‐2H‐pyrano[3,2‐c]quinoline‐2,5(6H)‐dione (20) exhibited good activates against Staph aureus surpassing the activity of reference antibiotic. Also, compounds 21 showed excellent antifungal activity against Candida albicans higher than fluconazole.

Highly Selective Hydrogenative Conversion of Nitriles into Tertiary, Secondary, and Primary Amines under Flow Reaction Conditions.

Flow reaction methods have been developed to selectively synthesize tertiary, secondary, and primary amines depending on heterogeneous platinum-group metal species under catalytic hydrogenation conditions using nitriles as starting materials. A 10 % Pd/C-packed catalyst cartridge affords symmetrically substituted tertiary amines in good to excellent yields. A 10 % Rh/C-packed catalyst cartridge enables the divergent synthesis of secondary and primary amines, with either cyclohexane or acetic acid as a solvent, respectively. Reaction parameters, such as the metal catalyst, solvent, and reaction temperature, and continuous-flow conditions, such as flow direction and second support of the catalyst in a catalyst cartridge, are quite important for controlling the reaction between the hydrogenation of nitriles and nucleophilic attack of in situ-generated amines to imine intermediates. A wide variety of aliphatic and aromatic nitriles could be highly selectively transformed into the corresponding tertiary, secondary, and primary amines by simply changing the metal species of the catalyst or flow parameters. Furthermore, the selective continuous-flow methodologies are applied over at least 72 h to afford three different types of amines in 80-99 % yield without decrease in catalytic activities.

Copper(II) Perfluorinated Carboxylate Complexes with Small Aliphatic Amines as Universal Precursors for Nanomaterial Fabrication.

Copper(II) carboxylate compounds with ethylamine and isopropylamine of the general formula [Cu2(RNH2)2(µ-O2CRf)4], where R = Et, iPr, and Rf = CnF2n+1, n = 1–6, were characterised in the condensed and gas phases by electron impact mass spectrometry (EI MS), IR spectroscopy, and thermal analysis. A mass spectra analysis confirmed the presence of metallated species in the gas phase. Among the observed fragments, the pseudomolecular ions [Cu2(RNH2)2(µ-O2CRf)3]+ were found, which suggests the dimeric structure of the studied complexes with axially N-coordinated ethyl- or isopropylamine molecules and bridging perfluorinated carboxylates. TGA studies demonstrated that copper transfer to the gas phase occurs even under atmospheric pressure. The temperature range of the [Cu2(RNH2)2(µ-O2CRf)4] and other copper carriers detection, observed in variable temperature infrared spectra, depends on the type of amine. The possible mechanisms of the decomposition of the tested compounds are proposed. The copper films were produced without additional reducing agents despite using Cu(II) CVD precursors in the chemical vapor deposition experiments. The layers of the gel-like complexes were fabricated in both spin- and dip-coating experiments, resulting in copper or copper oxide materials when heated. Dinuclear copper(II) carboxylate complexes with ethyl- and isopropylamine [Cu2(RNH2)2(µ-O2CRf)4] can be applied for the formation of metal or metal oxide materials, also in the nanoscale, by vapour and ‘wet’ deposition methods.

An Integrated Absorption–Mineralization Process for CO2 Capture and Sequestration: Reaction Mechanism, Recycling Stability, and Energy Evaluation

An integrated absorption–mineralization process (IAM) was proposed to desorb and mineralize CO2 captured by amine solvents using the semidry desulfurization slag (DFS). Four typical amine solvents ...

Insights into the Critical Role of Abundant-Porosity Supports in Polyethylenimine Functionalization as Efficient and Stable CO2 Adsorbents.

The emerging polyethylenimine (PEI)-functionalized solid adsorbents have witnessed significant development in the implementation of CO2 capture and separation because of their decent adsorption capacity, recyclability, and scalability. As an indispensable substrate, the importance of selecting porous solid supports in PEI functionalization for CO2 adsorption was commonly overlooked in many previous investigations, which instead emphasized screening amine types or developing complex porous materials. To this end, we scrutinized the critical role of different commercial porous supports (silica, alumina, activated carbon, and polymeric resins) in PEI impregnation in this study, taking into account multiple perspectives. Hereinto, the present results identified that abundant larger pore structures and surface functional groups were conducive to loading a considerable amount of PEI molecules. Various supports after PEI functionalization had great differences in adsorption capacities, amine efficiencies, and the corresponding optimal temperatures. In addition, more attention was paid to the role of porous supports in long-term stability during the consecutive adsorption-regeneration cycles, while N2 and CO2 purging as regeneration strategies, respectively. Especially, CO2-induced degradation due to urea species formation was specifically recognized in a SiO2-based adsorbent, which would induce serious concerns in CO2 cyclic capture. On the other side, we also confirmed that adopting conventional porous supports, for example, HP20, could achieve superior adsorption performance (above 4 mmol CO2/g) and cyclic stability (around 1% loss after 30 cycles) rather than the ones synthesized through complex approaches, which ensured the availability and scalability of PEI-functionalized CO2 adsorbents.

Compatibilization and Toughening of Biodegradable Polylactic Acid/Cellulose Acetate Films by Polyamide Amine Dendrimers

Due to the poor compatibility caused by the large difference in hydrophilicity and interface between polylactic acid (PLA) and cellulose acetate (CA), the blending of the two materials is difficult and the application is limited. To solve this problem, a type of polyamide amine (PAMAM) dendrimer was introduced to modify PLA/CA blends in this work. The results showed that PAMAM could improve the compatibility of PLA/CA blends, promote the distribution of CA and crystallization of PLA. At the same time, adding PAMAM could enhance the mechanical properties of the blend material, and the toughness and tear strength were increased by 551% and 141%, respectively. In addition, the incorporation of PAMAM increased hydrophobicity and oxygen permeability of PLA/CA blends, and the oxygen permeability could be increased by up to three orders of magnitude. Degradation test results showed that the blend exhibited good biodegradability. The overall performance of the PLA/CA blend film was optimal when the content of PAMAM was 3 phr. The biodegradable blend films with excellent performance provided wide application prospect in the food green packaging fields.

Boranephosphonates. Unraveling chemistry of the P-BH3 functional group

Nucleoside boranephosphonates are an important class of nucleotide analogues in which one of the non-bridging oxygen atoms has been replaced by a borane moiety (-BH3). In the presence of iodine nucleoside boranephosphonates react with 1° and 2° amines to afford the corresponding phosphoramidates, while with 3° and heteroaromatic amines, the borane group is modified forming new derivatives with the P-B-N bond system. We investigated mechanistic aspects of these reactions and showed that both of them followed the same initial steps that involved most likely formation of λ3-boranephosphonate as a key, electrophilic intermediate. It reacts further, eventually leading to either the corresponding phosphoramidate diester or the B-ammoniumboranephosphonate derivative, depending on the type of amine used.