Production Of Hydrazine Research Articles

Design and assessment of an advanced renewable energy system with hydrogen and monomethylhydrazine production for space shuttles

A new renewable energy-driven advanced plant is designed and developed to produce multiple useful outputs, namely electricity, heat, cooling, hydrogen, and monomethylhydrazine (as space shuttle fuel) using solar and wind energies locally available. A specific location needed for this kind of unique work is identified as the Kennedy Space Center (KSC), which is known as located on Merritt Island, in the state of Florida (USA). It is also one of the National Aeronautics and Space Administration's (NASA) ten field centers. Since December 1968, KSC has been NASA's primary launch center of American spaceflight, research, and technology. This paper presents a comprehensive analysis of the subsystems that constitute the newly proposed system potentially for KSC and highlights their complex relationships and synergies. Leveraging renewable energy sources, such as concentrated solar power (CSP) and wind energy, coupled with the subsystem uniquely, such as the regenerative Rankine cycle, multi-stage flash (MSF) desalination unit, hydrogen production process, and Li–Br absorption chiller, the KSC's system maximizes energy conversion efficiency while minimizing environmental impact. Noteworthy outcomes include daily water production of 177.63 kg/s and hydrogen production of 169.61 kg/day, alongside annual energy contributions of 212,692,688 kWh for CSP and 66,158,552 kWh for wind turbines. More than that, it produces 23.04 kg/s MMH as fuel. Additionally, the overall energy and exergy efficiencies of the system are 30.6% and 33% respectively. Despite challenges, such as low efficiencies in certain subsystems, like mono methyl hydrazine (MMH) production, ongoing research and development efforts aim to optimize processes and enhance sustainability.

Cobalt-Catalyzed Borylative Reduction of Azobenzenes to Hydrazobenzenes via a Diborylated-Hydrazine Intermediate.

Cobalt-catalyzed borylative reduction of azobenzenes using pinacolborane is developed. The simple cobalt chloride catalyst and reaction conditions make this protocol attractive for hydrazobenzene synthesis. This borylative reduction shows good functional group compatibility and can be readily scaled up to the gram scale. Preliminary mechanistic studies clarified the proton source of the hydrazine products. This cobalt-catalyzed azobenzene borylative reaction provides a practical protocol to prepare synthetically useful diborylated hydrazines.

Desulfurdioxidative N‐N Coupling of N‐Arylhydroxylamines and N‐Sulfinylanilines: Reaction Development and Mechanism

AbstractA highly efficient and chemoselective approach for the divergent assembling of unsymmetrical hydrazines through an unprecedented intermolecular desulfurdioxidative N−N coupling is developed. This metal free protocol employs readily accessible N‐arylhydroxylamines and N‐sulfinylanilines to provide highly valuable hydrazine products with good reaction yields and excellent functional group tolerance under simple conditions. Computational studies suggest that the in situ generated O‐sulfenylated arylhydroxylamine intermediate undergoes a retro‐[2π+2σ] cycloaddition via a stepwise diradical mechanism to form the N−N bond and release SO2.

Desulfurdioxidative N-N Coupling of N-Arylhydroxylamines and N-Sulfinylanilines: Reaction Development and Mechanism.

A highly efficient and chemoselective approach for the divergent assembling of unsymmetrical hydrazines through an unprecedented intermolecular desulfurdioxidative N-N coupling is developed. This metal free protocol employs readily accessible N-arylhydroxylamines and N-sulfinylanilines to provide highly valuable hydrazine products with good reaction yields and excellent functional group tolerance under simple conditions. Computational studies suggest that the in situ generated O-sulfenylated arylhydroxylamine intermediate undergoes a retro-[2π+2σ] cycloaddition via a stepwise diradical mechanism to form the N-N bond and release SO2.

Phylogeny-guided Characterization of Bacterial Hydrazine Biosynthesis Mediated by Cupin/methionyl tRNA Synthetase-like Enzymes.

Cupin/methionyl-tRNA synthetase (MetRS)-like didomain enzymes catalyze nitrogen-nitrogen (N-N) bond formation between Nω-hydroxylamines and amino acids to generate hydrazines, key biosynthetic intermediates of various natural products containing N-N bonds. While the combination of these two building blocks leads to the creation of diverse hydrazine products, the full extent of their structural diversity remains largely unknown. To explore this, we herein conducted phylogeny-guided genome-mining of related hydrazine biosynthetic pathways consisting of two enzymes: flavin-dependent Nω-hydroxylating monooxygenases (NMOs) that produce Nω-hydroxylamine precursors and cupin/MetRS-like enzymes that couple the Nω-hydroxylamines with amino acids via N-N bonds. A phylogenetic analysis identified the largely unexplored sequence spaces of these enzyme families. The biochemical characterization of NMOs demonstrated their capabilities to produce various Nω-hydroxylamines, including those previously not known as precursors of N-N bonds. Furthermore, the characterization of cupin/MetRS-like enzymes identified five new hydrazine products with novel combinations of building blocks, including one containing non-amino acid building blocks: 1,3-diaminopropane and putrescine. This study substantially expanded the variety of N-N bond forming pathways mediated by cupin/MetRS-like enzymes.

B(C6F5)3‐Catalyzed N‐Allylation of Hydrazines with Allylic Alcohols

AbstractAn N‐allylation of monosubstituted acyl hydrazines with allylic alcohols has been developed by using B(C6F5)3 catalysis. This protocol allows for convenient access to various synthetically useful N‐allylated hydrazine products in 48–96% yields with broad substrate scope and wide functional group compatibility. The operationally simple reaction proceeds without calling for stringent removal of air and moisture, and can be readily scaled up to gram scale. Preliminary mechanistic studies support the generation of an allylic carbon cation that is involved in the catalytic cycle, and the reaction proceeds via the in situ formation of diallyl ethers as intermediates.

Strategic design of VO2 encased in N-doped carbon as an efficient electrocatalyst for the nitrogen reduction reaction in neutral and acidic media.

Electrocatalytic nitrogen fixation to ammonia (NH3), a precursor for fertilizer production and a promising energy carrier, has garnered widespread interest as an environment-friendly and sustainable alternative to the energy-intensive fossil-feedstock-dependent Haber-Bosch process. The large-scale deployment of this process is contingent on the identification of inexpensive, Earth-abundant systems that can operate efficiently, irrespective of the electrolyte pH for the selective production of NH3. In this regard, we discuss the scalable synthesis of VO2 anchored on N-doped carbon (VO2@CN), and its applicability as a robust electrocatalyst for the nitrogen reduction reaction (NRR). Benefitting from the presence of exposed VO2, which presumably acts as the active site for nitrogen reduction, and its activity over a broad pH range (from acidic to neutral), VO2@CN exhibits a high NH3 yield of 0.31 and 0.52 μmol h-1 mgcat-1 and a maximum Faradaic efficiency (FE) of 67.9% and 61.9% at -0.1 V vs. RHE, under neutral and acidic conditions, respectively. The obscured reaction intermediates of the NRR were identified from in situ ATR-IR studies under both electrolyte conditions. Additionally, the high selectivity of the catalyst was ascertained from the absence of hydrazine production and the competing hydrogen evolution reaction (HER). However, ammonia production underwent a reduction over 12 h of continuous operation presumably owing to the leaching of catalyst under these electrolysis conditions, which was more pronounced in electrolytes with acidic pH. Overall, the present report unveils the performance of an earth-abundant vanadium oxide-based system as an efficient electrocatalyst for the NRR under acidic and neutral pH conditions.

Catalytic Deoxygenative Reduction of Hydrazides to Hydrazines via B(C6F5)3‐Catalyzed Hydrosilylation

AbstractThe catalytic deoxygenative reduction of hydrazides to the corresponding alkyl hydrazine with PhSiH3 via B(C6F5)3‐catalyzed hydrosilylation is reported. This metal‐free protocol is compatible with various acylhydrazides and diacylhydrazides, giving rise to a variety of structurally diverse alkyl hydrazine products in 63–95% yields. The proper selection of borane catalyst and hydrosilane reductant is essential for catalysis. Mechanistic investigations reveal that the reaction involves a hydrazone intermediate.

Immunonutrition and Hepatoprotectant Aspects of <i>Moringa Oleifera</i> Leaf Nanoemulsion Syrup as an Antituberculosis Adjuvant for Children with Tuberculosis

Tuberculosis in children is a global health problem that decreases the quality of life of children. Based on data from the Indonesian Ministry of Health in 2016, nearly 69.000 children had tuberculosis and the case keeps increasing every year. Moringa oleifera leaf nanoemulsion syrup has immunonutrition and hepatoprotectant effects in children with tuberculosis. Moringa oleifera leaf nanoemulsion syrup contains proteins, micronutrients, and minerals which have a biological role as an immunity agent and prevent toxic effects of tuberculosis drugs. Until now, the use of Moringa oleifera leaf nanoemulsion syrup has been carried out for the immunomodulatory and hepatoprotective aspects. Immunomodulatory and hepatoprotective aspects will be discussed further in this literature review. The sources of articles in this literature review are pubmed.com, ncbi.com, plosone.com, sciencedirect.com, and googleschoolar.com from 2010-2020, except when there is no new research against the article. The authors searched for the keywords: "immunonutrition", "tuberculosis in children", "hepatoprotectant", and "Moringa oleifera". As an immunomodulator, Moringa oleifera leaf nanoemulsion syrup stimulate activation of polimorphonuclear (PMN) cells. As a hepatoprotectant, Moringa oleifera leaf nanoemulsion syrup work by reducing the side effects of conventional tuberculosis drugs such as rifampicin by suppressing the action of cytochrome p450 (CYP1A2 and CYP2B), thus decreases the production of toxic hydrazine which causes liver toxicity in tuberculosis patient. Seeing the various interests in the immunomodulatory and hepatoprotective aspects, Moringa oleifera leaf nanoemulsion syrup can be used as an adjuvant therapy in overcoming tuberculosis in children by stimulating the activation of immunity cell such as PMN, increasing nutrient absorption, and suppressing the action of cytochrome p450 (CYP1A2 and CYP2B).

Tetrahedral W4 cluster confined in graphene-like C2N enables electrocatalytic nitrogen reduction from theoretical perspective

Exploring the format of active site is essential to further the understanding of an electrocatalyst working under ambient conditions. Herein, we present a DFT study of electrocatalytic nitrogen reduction (eNRR) on W4 tetrahedron embedded in graphene-like C2N (denoted as W4@C2N). Our results demonstrate that N-affinity of active sites on W4 dominate over single-atom site, rendering *NH2 + (H+ + e−) →*NH3 invariably the potential-determining step (PDS) of eNRR via consecutive or distal route (U L = −0.68 V) to ammonia formation. However, *NHNH2 + (H+ + e−) →*NH2NH2 has become the PDS (U L = −0.54 V) via enzymatic route towards NH2NH2 formation and thereafter desorption, making W4@C2N a potentially promising catalyst for hydrazine production from eNRR. Furthermore, eNRR is competitive with hydrogen evolution reaction (U L = −0.78 V) on W4@C2N, which demonstrated sufficient thermal stability and electric property for electrode application.

Asymmetric Synthesis of γ-Amino-Functionalised Vinyl Sulfones: De Novo Preparation of Cysteine Protease Inhibitors

AbstractThe enantioselective azo-based α-amination of an aldehyde followed by a Horner–Wadsworth–Emmons-based vinyl sulfone formation is reported. The thus obtained optically active N,N′-diprotected trans-(phenylsulfonyl)vinyl hydrazine products were then converted into the corresponding N-functionalised trans-(phenylsulfonyl)vinyl amines. Specifically, reaction of 4-phenylbutanal with di-tert-butyl azodicarboxylate (DBAD) in the presence of l- or d-proline, followed by addition of diethyl [(phenylsulfonyl)methyl]phosphonate, gave either enantiomer of di-tert-butyl trans-1-[5-phenyl-1-(phenylsulfonyl)pent-1-en-3-yl]hydrazine-1,2-dicarboxylate. The enantiomeric excesses of the (+)- and (–)-enantiomers prepared in this manner were in the range 86–89%. The conversion of these γ-hydrazino vinyl sulfones into the corresponding γ-amino-substituted compounds was achieved following a Boc deprotection, Zn reduction, N-functionalisation sequence. This three-step sequence was reasonably efficient (approx. 50%) and no erosion of enantiopurity was found to have taken place. The compounds accessed via this process include both enantiomers of tert-butyl trans-[5-phenyl-1-(phenylsulfonyl)pent-1-en-3-yl]carbamate and epimeric dipeptide mimetics including 4-methyl-N-{(S)-1-oxo-3-phenyl-1-[((S,E)-5-phenyl-1-(phenylsulfonyl)pent-1-en-3-yl)amino]propan-2-yl}piperazine-1-carboxamide (also known as K777).

Efficient reductions of dimethylhydrazones using preformed primary amine boranes

A convenient method for the reduction of N,N-dimethylhydrazones using amine borane complexes generated in situ is described. It was found that primary amine borane complexes performed exceedingly well at reducing N,N-dimethylhydrazones in as little as 1.1 equivalents, furnishing the corresponding air-sensitive hydrazine products in excellent yields.

Accelerated and Scalable C(sp3)-H Amination via Decatungstate Photocatalysis Using a Flow Photoreactor Equipped with High-Intensity LEDs.

Carbon–nitrogen bonds are ubiquitous in biologically active compounds, prompting synthetic chemists to design various methodologies for their preparation. Arguably, the ideal synthetic approach is to be able to directly convert omnipresent C–H bonds in organic molecules, enabling even late-stage functionalization of complex organic scaffolds. While this approach has been thoroughly investigated for C(sp2)–H bonds, only few examples have been reported for the direct amination of aliphatic C(sp3)–H bonds. Herein, we report the use of a newly developed flow photoreactor equipped with high intensity chip-on-board LED technology (144 W optical power) to trigger the regioselective and scalable C(sp3)–H amination via decatungstate photocatalysis. This high-intensity reactor platform enables simultaneously fast results gathering and scalability in a single device, thus bridging the gap between academic discovery (mmol scale) and industrial production (>2 kg/day productivity). The photocatalytic transformation is amenable to the conversion of both activated and nonactivated hydrocarbons, leading to protected hydrazine products by reaction with azodicarboxylates. We further validated the robustness of our manifold by designing telescoped flow approaches for the synthesis of pyrazoles, phthalazinones and free amines.

Near-infrared cyanine-based fluorescent probe: Rapidly visualizing the in situ release of hydrazine in living cells and zebrafish

Visualizing the in situ release of hydrazine in living systems would give impetus to understand the hydrazine production in the course of drug metabolism in vivo, which is very meaningful but challenging due to the lack of appropriate analytical tools. Here, inspired by the advantages of real-time, non-destructive, and visualization of fluorescence imaging technology, we rationally designed near-infrared cyanine-based fluorescent probe B-CyAS, which possessed outstanding biological compatibility, and a fast response toward (1–100 μM) N2H4 within 7 min. With isoniazid as a model medicine, the dynamic metabolic process of isoniazid to N2H4 in HepG2 cells and zebrafish was successfully in situ visualized, which might provide a promising tool and method for monitoring and evaluating toxic metabolites in biological systems.

Ruthenium-Catalyzed Enantioselective Hydrogenation of Hydrazones.

Prochiral hydrazones undergo efficient and highly selective hydrogenation in the presence of a chiral diphosphine ruthenium catalyst, yielding enantioenriched hydrazine products (up to 99% ee). The mild reaction conditions and broad functional group tolerance of this method allow access to versatile chiral hydrazine building blocks containing aryl bromide, heteroaryl, alkyl, cycloalkyl, and ester substituents. This method was also demonstrated on >150 g scale, providing a valuable hydrazine intermediate en route to an active pharmaceutical ingredient.

Ammonia decomposition to clean hydrogen using non-thermal atmospheric-pressure plasma

The plasma decomposition of ammonia was studied as a function of applied voltage/power, residence time including length of an inner electrode and flow rate of reactant gases, partial pressure of ammonia, and amount and the metal species of the inner electrodes. The ammonia decomposition rates were in excellent agreement with the hydrogen production rates and no hydrazine production was detected, indicating the clean decomposition of ammonia in the current system. The decomposition rates were dependent on the applied power and the residence time and independent of metal species of the inner electrodes, in contrast to the strong dependence of the ammonia synthesis reaction on the metal species. A hydrogen yield of 100% was achieved with an applied power of approximately 50 W and a residence time of 1.2 s at ambient temperature and atmospheric pressure, with an applied voltage of 5 kV and a frequency of 50 kHz.

M-C2B10H11HgCl/AgOTf-Catalyzed Reaction for Reductive Deoxygenation

A m-C2B10H11HgCl/AgOTf-catalyzed reaction of allyl silyl ethers with N-Boc-N′-tosylhydrazine has been developed. Under mild conditions, the resulting allyl hydrazine products were transformed into naked alkenes in good yield. Furthermore, the used m-C2B10H11HgCl could be recovered quantitatively.

Studi Produksi Hidrasin VIA Proses Urea

The use of hydrazine,N2H4 becomes very broad nowadays, in the production of polymer such as automobile air bags, in pharmacy, and in the water treatment for oxygen scavenge. Three commercial processes are available for hydrazine production , i.e. via Rasching-Olin, Ketazin, and Urea process. The operating condition for the later process is very mild compared to with the other two processes and hence requires simple processing equipments. This paper concerns with the kinetic study on production and on the effect of deactivator/ inhibitor during hydrazine bench-scale production via Urea process. Operating condition are at 1 bar and at temperature range 5-100 0C. The yield of the hydrazine and its concentration with varying reactants, NaOH, hypochlorite, and urea during the cource of reaction are presented. Futher, the effect of gelatin as the deactivator toward hydrazine yield is futher examined. A kinetic model is proposed and used to predict yield of hydrazine. The predicted yield is in close agreement with the experimental yield.Keywords : hydrazine, bench-scale production, kinetic model, oxygen scavenger, inhibitor, geltine

Carbon-Nitrogen Bond Formation via the Vanadium Oxo Catalyzed Sigmatropic Functionalization of Allenols.

A vanadium catalyzed 1,3-rearrangement of allenols to form transient vanadium enolates that selectively couple with electrophilic nitrogen sources is reported even in the presence of competing simple protonation and Alder-ene pathways. Hydrazine products can be cyclized in a 6-endo-trig fashion which, upon reductive cleavage of the N-N bond, yield 1,4-diamines. Additionally, cleavage of the N-N bond before cyclization can be achieved to form β-hydroxy amines, a common structural motif of biologically active compounds.

Putting chromium on the map for N2 reduction: production of hydrazine and ammonia. A study of cis-M(N2)2 (M = Cr, Mo, W) bis(diphosphine) complexes.

The first complete structurally and spectroscopically characterized series of isostructural Group 6 N2 complexes is reported. Protonolysis experiments on cis-[M(N2)2(P(Et)N(R)P(Et))2] (M = Cr, Mo, W; R = 2,6-difluorobenzyl) reveal that only Cr affords N2H5(+) and NH4(+) from the reduction of the N2 ligands.