Formation Of Products Research Articles

Copper Catalyzed Borylation of Alkynes: An Experimental Mechanistic Study.

The copper catalyzed hydroboration of alkynes with B2pin2 was studied by in detail studies of individual relevant steps along the catalytic pathway. A number of reaction steps were retraced by in situ NMR spectroscopy as well as central intermediates and side-products were isolated and comprehensively characterized. A copper boryl complex is central to the catalytic process by inserting the terminal alkyne substrate into the B-Cu bond. The selectivity of this step - depending on the NHC auxiliary ligand - determines the α/β selectivity observed in the product. The latter complex is protonated by the auxiliary alcohol reagent resulting in hydroboration product formation and formation of a Cu alkoxido complex. Reaction of the latter with B2pin2 results in the regeneration of the central copper boryl complex. This alcoholysis step depends on the acidity of the alcohol, in particular on the relative acidity of the alcohol vs. the alkyne substrate. A number of side reactions leading to the hydrogenation product of the alkyne substrate and a bis hydroborated product were identified and studied in some detail. It is concluded that the performance of a particular catalytic system depends crucially on the relative acidities of the reagents and generalizations may be difficult.

THE RELATIONSHIP BETWEEN OXIDATIVE STRESS AND NEUROLOGICAL DISORDERS: MINI REVIEW

Oxidative stress is one of the main causes of neuronal dysfunction and death, mainly due to excessive formation of reactive oxygen species and depletion of antioxidant reserves. Oxidative stress is characterized by an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense mechanisms of the body. This process is involved in the onset and development of many neurological diseases. In this review, we analyzed and summarized the results of studies showing the association of neurological diseases, such as stroke, Parkinson’s disease, and other neurological diseases, with excessive formation of oxidative stress products. This article aims to provide an overview of the relationship between oxidative stress and a range of neurological conditions, shedding light on the underlying mechanisms and potential therapeutic implications.

Unveiling the Potential of Halide Perovskites for Seasonally Adaptive CO2 Photoreduction under Low Light Conditions

AbstractThe viability of double perovskite Cs2AgBiBr6 in low‐light environments is studied for CO2 photoreduction. It is observed that light intensity significantly influences product formation with I0.56 depending on the overall product formation rate. The photodetection measurement reveals that photocurrent as a function of incident power follows a power law ∝ I0α with α = 0.80, which is attributed to the carrier trapping at higher light power. Furthermore, power‐dependent transient absorption spectroscopy is studied and observed that at higher fluence, carrier scattering can be dominating. Interestingly, it is found that at higher power, hot carrier relaxation dynamics are altered, and electron‐phonon coupling is enhanced, resulting in a lower carrier concentration participating in the photocatalytic reaction, which can limit charge carrier extraction and CO2 reduction. This study highlights the potential of perovskite semiconductors as promising candidates for photocatalytic reactions in low‐light conditions, broadening their applicability in real‐world scenarios.

Switching between the [2π+2σ] and Hetero‐[4π+2σ] Cycloaddition Reactivity of Bicyclobutanes with Lewis Acid Catalysts Enables the Synthesis of Spirocycles and Bridged Heterocycles

The exploration of the complex chemical diversity of bicyclo[n.1.1]alkanes and their use as benzene bioisosteres has garnered significant attention over the past two decades. Regiodivergent syntheses of thiabicyclo[4.1.1]octanes (S‐BCOs) and highly substituted bicyclo[2.1.1]hexanes (BCHs) using a Lewis acid‐catalyzed formal cycloaddition of bicyclobutanes (BCBs) and 3‐benzylideneindoline‐2‐thione derivatives have been established. The first hetero‐(4+3) cycloaddition of BCBs, catalyzed by Zn(OTf)2, was achieved with a broad substrate scope under mild conditions. In contrast, the less electrophilic BCB ester undergoes a Sc(OTf)3‐catalyzed [2π+2σ] reaction with 1,1,2‐trisubstituted alkenes, yielding BCHs with a spirocyclic quaternary carbon center. Control experiments and preliminary theoretical calculations suggest that the diastereoselective [2π+2σ] product formation may involve a concerted cycloaddition between a zwitterionic intermediate and E‐1,1,2‐trisubstituted alkenes. Additionally, the hetero‐(4+3) cycloaddition may involve a concerted nucleophilic ring‐opening mechanism.

Switching between the [2π+2σ] and Hetero-[4π+2σ] Cycloaddition Reactivity of Bicyclobutanes with Lewis Acid Catalysts Enables the Synthesis of Spirocycles and Bridged Heterocycles.

The exploration of the complex chemical diversity of bicyclo[n.1.1]alkanes and their use as benzene bioisosteres has garnered significant attention over the past two decades. Regiodivergent syntheses of thiabicyclo[4.1.1]octanes (S-BCOs) and highly substituted bicyclo[2.1.1]hexanes (BCHs) using a Lewis acid-catalyzed formal cycloaddition of bicyclobutanes (BCBs) and 3-benzylideneindoline-2-thione derivatives have been established. The first hetero-(4+3) cycloaddition of BCBs, catalyzed by Zn(OTf)2, was achieved with a broad substrate scope under mild conditions. In contrast, the less electrophilic BCB ester undergoes a Sc(OTf)3-catalyzed [2π+2σ] reaction with 1,1,2-trisubstituted alkenes, yielding BCHs with a spirocyclic quaternary carbon center. Control experiments and preliminary theoretical calculations suggest that the diastereoselective [2π+2σ] product formation may involve a concerted cycloaddition between a zwitterionic intermediate and E-1,1,2-trisubstituted alkenes. Additionally, the hetero-(4+3) cycloaddition may involve a concerted nucleophilic ring-opening mechanism.

Origin of deactivation of aqueous Na–CO2 battery and mitigation for long-duration energy storage

The development of long-duration energy storage technology is crucial to facilitate the efficient utilization of renewable energy sources while mitigating carbon dioxide production. In this study, we investigate the deactivation and reactivation mechanisms of the aqueous Na–CO2 battery during extended cycling. We have designed the cathode to include non-precious intermetallic catalysts. As the cell undergoes repeated cycles, the voltage polarization during discharge progressively rises, eventually leading to the cell's deactivation and formation of decomposition products clogging the electrode surface. Results obtained from comprehensive characterization techniques, including conductive atomic force microscopy (cAFM), Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and inductively coupled plasma-mass spectrometry provide insight into the decomposition products. We also showcase an electrochemical approach for regeneration of these aqueous cells. Our findings, along with the insights we have gained, provide a path toward creating long-duration systems with self-healing properties.

New Method for Obtaining Carboxylic Derivatives of Oxazolo[5,4-b]pyridine Based on 3-Aminopyridine-2(1H)-ones

Current methods for synthesis of oxazolo[5,4-b]- and oxazolo[4,5-b]pyridines have several limitations, such as severe reaction conditions, lengthy reaction times, low yields and concurrent formation of side reaction products. This article presents the results of study focused on a one-step method for the synthesis of new derivatives of oxazolo[5,4-b]pyridine incorporating an aliphatic carboxylic group as a linker. During the investigation of acylation reactions of 3-aminopyridine-2(1H)-ones with cyclic anhydrides of dicarboxylic acids (succinic, maleic and glutaric), it was found that the monoamides formed at the initial stage undergo intramolecular cyclization yielding derivatives of oxazolo[5,4-b]pyridine. Subsequently, the reaction conditions were studied and optimized to achieve the target compounds with high yield and purity. The potential anti-inflammatory activity of the obtained derivatives of oxazolo[5,4-b]pyridine was evaluated by molecular docking method using AutoDock Vina software. Compounds 11-14b exhibited higher binding affinity with the selected target protein Prostaglandin synthase-2 (1CX2) compared to the reference anti-inflammatory drug diclofenac. Thus, taking into account the results of in silico analyses, the newly synthesized oxazolo[5,4-b]pyridine derivatives based on 3-aminopyridine-2(1H)-ones are promising candidates for further investigation of their potential anti-inflammatory activity through in vivo methods.

Deciphering complexity in Pd–catalyzed cross-couplings

Understanding complex reaction systems is critical in chemistry. While synthetic methods for selective formation of products are sought after, oftentimes it is the full reaction signature, i.e., complete profile of products/side-products, that informs mechanistic rationale and accelerates discovery chemistry. Here, we report a methodology using high-throughput experimentation and multivariate data analysis to examine the full signature of one of the most complicated chemical reactions catalyzed by palladium known in the chemical literature. A model Pd-catalyzed reaction was selected involving functionalization of 2-bromo-N-phenylbenzamide and multiple bond activation pathways. Principal component analysis, correspondence analysis and heatmaps with hierarchical clustering reveal the factors contributing to the variance in product distributions and show associations between solvents and reaction products. Using robust data from experiments performed with eight solvents, for four different reaction times at five different temperatures, we correlate side-products to a major dominant N-phenyl phenanthridinone product, and many other side products.

MitoTempo protects against nε-carboxymethyl lysine-induced mitochondrial dyshomeostasis and neuronal cells injury

Enhanced formation of advanced glycation end products (AGEs) is a pivotal factor in diabetes pathophysiology, increasing the risk of diabetic complications. Nε-carboxy-methyl-lysine (CML) is one of the most relevant AGEs found in several tissues including the peripheral blood of diabetic subjects. Despite recognizing diabetes as a risk factor for neurodegenerative diseases and the documented role of mitochondrial abnormalities in this connection, the impact of CML on neuronal mitochondria and its contribution to diabetes-related neurodegeneration remain uncertain. Here, we evaluated the effects of CML in differentiated SH-SY5Y human neuroblastoma cells. Due to the association between mitochondrial dysfunction and increased production of reactive oxygen species (ROS), the possible protective effects of MitoTempo, a mitochondria-targeted antioxidant, were also evaluated. Several parameters were assessed namely cells viability, mitochondrial respiration and membrane potential, ATP and ROS production, Ca2+ levels, mitochondrial biogenesis and dynamics, mito/autophagy, endoplasmic reticulum (ER) stress and amyloidogenic and synaptic integrity markers. CML caused pronounced mitochondrial defects characterized by a significant decrease in mitochondrial respiration, membrane potential, and ATP production and an increase in ROS production. An accumulation of individual mitochondria associated with disrupted mitochondrial networks was also observed. Furthermore, CML caused mitochondrial fusion and a decrease in mitochondrial mass and induced ER stress associated with altered unfolded protein response and Ca2+ dyshomeostasis. Moreover, CML increased the protein levels of β-secretase-1 and amyloid precursor protein, key proteins involved in Alzheimer's Disease pathophysiology. All these effects contributed to the decline in neuronal cells viability. Notable, MitoTempo was able to counteract most of CML-mediated mitochondrial defects and neuronal cells injury and death. Overall, these findings suggest that CML induces pronounced defects in neuronal mitochondria and ER stress, predisposing to neurodegenerative events. More, our observations suggest that MitoTempo holds therapeutic promise in mitigating CML-induced mitochondrial imbalance and neuronal damage and death.

Enhancing CO2 Electroreduction to C2 Products on Metal-Nitrogen Sites by Regulating H2O Dissociation.

Water dissociation remarkably affects the CO2 reduction to CO and HCOOH, but whether it is effective for two-carbon product formation on M-Nx-containing catalysts is still ambiguous. Herein, by using a fluorinated metal phthalocyanine (MPc-F) as the M-N4-based model electrocatalyst, experimental and theoretical results reveal that the H2O-dissociation-induced active H species decrease the overpotential of the *CO hydrogenation to *CHO and facilitate the C-C coupling between *CHO and neighboring CO. Such an effect is strengthened by an increase in the *CO binding strength on the metal center. By introducing CuPc as the H2O dissociation catalyst into MPc-F (MPc-F/CuPc) to accurately regulate the H2O dissociation, the faradic efficiency of C2 products on FePc-F/CuPc and MnPc-F/CuPc increases from 0% (FePc-F and MnPc-F) to 26 and 36%, respectively. This work develops a novel strategy for enhancing the selectivity of M-Nx-containing catalysts to C2 products and reveals the correlation between H2O dissociation and C2 product formation.

Homogenous Oxidizing Oligomerization Coupled with Coagulation for Water Purification

Natural manganese oxides could induce the intermolecular coupling reactions among small-molecule organics in aqueous environments, which is one of the fundamental processes contributing to natural humification. These processes could be simulated to design novel advanced oxidation technology for water purification. In this study, periodate (PI) was selected as the supplementary electron-acceptor for colloidal manganese oxides (Mn(IV)aq) to remove phenolic contaminants from water. By introducing polyferric sulfate (PFS) into the Mn(IV)aq/PI system and exploiting the flocculation potential of Mn(IV)aq, a post-coagulation process was triggered to eliminate soluble manganese after oxidation. Under acidic conditions, periodate exists in the H4IO6− form as an octahedral oxyacid capable of coordinating with Mn(IV)aq to form bidentate complexes or oligomers (Mn(IV)-PI*) as reactive oxidants. The Mn(IV)-PI* complex could induce cross-coupling process between phenolic contaminants, resulting in the formation of oligomerized products ranging from dimers to hexamers. These oligomerized products participate in the coagulation process and become stored within the nascent floc due to their catenulate nature and strong hydrophobicity. Through coordination between Mn(IV)aq and H4IO6−, residual periodate is firmly connected with manganese oxides in the floc after coagulation and could be simultaneously separated from the aqueous phase. This study achieves oxidizing oligomerization through a homogeneous process under mild conditions without additional energy input or heterogeneous catalyst preparation. Compared to traditional mineralization-driven oxidation techniques, the proposed novel cascade processes realize transformation, convergence, and separation of phenolic contaminants with high oxidant utilization efficiency for low-carbon purification.

Initial Characteristics of Alkali–Silica Reaction Products in Mortar Containing Low-Purity Calcined Clay

An alkali–silica reaction (ASR) is a chemical process that leads to the formation of an expansive gel, potentially causing durability issues in concrete structures. This article investigates the properties and behaviour of ASR products in mortar with the addition of low-purity calcined clay as an additional material. This study includes an evaluation of the expansion and microstructural characteristics of the mortar, as well as an analysis of the formation and behaviour of ASR products with different contents of calcined clay. Expansion tests of the mortar beam specimens were conducted according to ASTM C1567, and a detailed microscopic analysis of the reaction products was performed. Additionally, their mechanical properties were determined using nanoindentation. This study reveals that with an increasing calcined clay content, the amount of the crystalline form of the ASR gel decreases, while the nanohardness increases. The Young’s modulus of the amorphous ASR products ranged from 5 to 12 GPa, while the nanohardness ranged from 0.41 to 0.67 GPa. The obtained results contribute to a better understanding of how the incorporation of low-purity calcined clay influences the ASR in mortar, providing valuable insights into developing sustainable and durable building materials for the construction industry.

Difference comparison of characteristic aroma compounds between braised pork cooked by traditional open-fire and induction cooker and the potential formation cause under electromagnetic cooking

The characteristic aroma compounds of braised pork were identified through molecular sensory science and PLSR analysis, and the difference between two cooking methods, traditional open-fire (BPF) and induction cooker (BPC), was compared. Seventeen aroma compounds with odor activity values (OAVs) > 1 were identified in both samples. BPF revealed higher OAVs for most of the aroma compounds compared to BPC, and the higher aroma quality. Aroma recombination and omission experiments confirmed that twelve aroma compounds significantly contributed to the characteristic aroma of braised pork, and eight compounds such as hexanal, (E)-2-octenal, and methanethiol were further confirmed as important contributors by PLSR analysis. Furthermore, PLSR analysis clarified the role of aldehydes such as hexanal, (E)-2-octenal, and (E,E)-2,4-decadienal in contributing to fatty attribute, whereas methanethiol was responsible for the meaty aroma. These characteristic aroma compounds mainly derived from lean meat due to its high content of phospholipids, and the exogenous seasonings contributed to the balanced characteristic aroma profile of braised pork by altering the distribution of these characteristic aroma compounds. Variations in heating parameters affected the formation of lipid oxidation and Strecker degradation products, which might explain aroma discrepancy between braised pork cooked by two methods with different heat transfer efficiencies.

Purple Light-Promoted Coupling of Bromopyridines with Grignard Reagents via SET.

Alkyl- and arylpyridines and 2,2'-bipyridines are conventionally prepared by Minisci reactions of pyridines and transition metal-catalyzed coupling reactions of halopyridines. Herein, purple light-promoted radical coupling reactions of 2- or 4-bromopyridines with Grignard reagents in Et2O or a mixture of Et2O and tetrahydrofuran in regular glassware without the need for a transition metal catalyst were disclosed for the first time. Methyl, primary and secondary alkyl, cycloalkyl, aryl, heteroaryl, pyridyl, and alkynyl Grignard reagents were compatible with the protocol. As a result, alkyl- and arylpyridines and 2,2'-bipyridines were easily prepared. Single electron transfer from the Grignard reagent to bromopyridine was stimulated by purple light. An electron extruded from the dimerization of the Grignard reagent worked as the catalyst. Light on/off experiments indicated that constant irradiation was required for product formation. Studies of radical clock substrates verified the involvement of a pyridyl radical from bromopyridine and the noninvolvement of an alkyl or aryl radical from the Grignard reagent. The available proof supports a photoinduced SRN mechanism for the new coupling reactions.

CHIRAL SWITCHING CONTROL OF PHARMACEUTICAL SUBSTANCES

Objective: The aim of this study was to demonstrate that chiral switching should be recognized as a widespread phenomenon that extends beyond the production of pure enantiomeric drugs. Methods: To investigate the optical activity of substances from various chemical classes, enantiomers of chiral compounds (Sigma-Aldrich, USA) were chosen: valine and its racemic form (D-valine, L-valine, and racemic valine with optical purity ≥ 99%), L-ascorbic acid (content ≥ 99%), carbohydrates (D-glucose, D-galactose, L-galactose, contents ≥ 99.5%). Solutions were prepared using deuterium-depleted water (DDW–"light" water, D/H=4 ppm), natural deionized high-ohmic water (BD, D/H=140 ppm), and heavy water (99.9% D2O; Sigma-Aldrich). Optical activity was measured using the Atago POL-1/2 polarimeter. Results: One of the components in the racemic medication mixture can act as an inert agent, exhibit toxicity, or undergo undesirable biotransformation mechanisms, resulting in the formation of products with unknown properties. It has been established that a change in the deuterium/protium (D/H) ratio in water leads to a change in the equilibrium and kinetic characteristics of optically active compounds across various chemical classes, such as amino acids, carboxylic acids, and carbohydrates. An inequality was observed in the absolute values of the optical rotation of the L-and D-isomers of valine and galactose, depending on the D/H isotope ratio. The impact of chiral water clusters on optical rotation accounts for the sudden shift in the specific rotation of dilute solutions (less than 0.5%) of L-ascorbic acid in water, based on the D/H ratio. The influence of the isotopic composition of water was confirmed by studying the temperature-dependent mutarotation kinetics of D-glucose and L-and D-galactose in Arrhenius coordinates. The mutarotation process in natural high-resistivity water is characterized by an activation energy (Ea) of 40.8±1.4 kJ mol-1, while in deuterium-depleted water, Ea = 63.6±3.5 kJ mol-1. This results in a kinetic isotope effect for deuterium (KIED) of 1.6. Conclusion: Methodological approaches have been developed to control chiral switching based on the isotopic composition of water in vivo and in vitro. The study of changes in the optical activity of hierarchical structures in the human body, the influence of solvent properties on the mechanisms of optical rotation, as well as the use of KIED values, can be utilized to monitor various chiral transitions in vitro and living organisms.

Use of metakaolin with a low surface area and rich in quartz and iron as a precursor in the production of structural alkali-activated concrete

Pumpable and machineable alkali-activated structural concretes are made using low-reactivity metakaolin with high quartz and iron contents. The effects and interaction of alkaline concentration (NaOH - 8, 10, 12, 14, and 16 M) and ratio of alkaline reagents (Na2SiO3/NaOH - 1.0, 1.5, 2.0, 2.5, and 3.0) on their properties were accessed using 2k complete factorial design. Higher concentrations of alkaline solutions resulted in faster hardening, decreased material deformation, and increased mechanical strength, with higher elastic modulus, lower damping, lower water absorption, and porosity. With time, the elastic modulus increased, and the dynamic damping decreased, suggesting the homogeneous formation of alkaline-activated products, confirming the proper configuration of the hardening process. The factorial design allowed for determining the ideal dosage for producing the material, indicating that the alkaline concentration (NaOH) should be 10 M and the Na2SiO3/NaOH ratio should be 2.5. They analyzed the possible combinations that allowed obtaining a material with adequate characteristics for the structural application.

What Got Us Here Won't Get Us There: Critical History in Radical Black Re-imaginations of Canadian Nursing Histories.

As a "foursome" of nursing history students and scholars, upcoming, junior, and seasoned, we presented a panel on new work and possibilities related to histories of Blackness and Black nurses in Canadian nursing history. Our presentation was the 2023 keynote Hannah Panel Presentation for the joint Canadian Society for the History of Medicine (CSHM-SCHM) and the Canadian Association for the History of Nursing (CAHN-ACHN) conference. Reflecting and expanding our perspectives, we share the relevance and significance of engaging with histories of Canadian Blackness and (in)visibility of Blackness in nursing history. This paper considers the overarching question of how does engaging with histories of Canadian Blackness serve as an anti-racist strategy when examining, analyzing and understanding the history of nursing and health care? A core tenant of this work aims at acknowledging how institutional relationships of power are reproduced within scholarship unless there is space for radical re-imaginations. The disruption to power is achieved by exploring the connections between nursing and history from the perspective of Black nurses' history or Black feminist thought. We also disrupt power by our form, in challenging expectations of scientific inquiry as the only format of valid knowledge production within the discipline. Possibilities of arts-based methodology as a site for democratization in nursing knowledge are evoked through the metaphoric language (water, fire, air and earth) interwoven within the text. We highlight how each of us engages with nursing history, further complicating previous narratives of our collective Canadian past. In publishing our thoughts on historical inquiry in a nursing journal, we hope to provoke more curiosity and interest in history within our discipline as a site for liberation!

Immobilization properties and reaction mechanism of municipal solid waste incineration fly ash with alkali activation technology

Municipal solid waste incineration fly ash (MSWIFA) needs proper treatment prior to security landfilling because of considerable amounts of heavy metals and soluble chloride. Nowadays, alkali activation technology has become an effective solidification/stabilization (S/S) technology for MSWIFA. But few studies have been systematically carried out on the preparation techniques and reaction mechanism of MSWIFA S/S body. The effects of the technical parameters (alkali activator, sodium silicate modulus, alkali equivalent, water-solid ratio, curing regime) on the immobilization properties (compressive strength and heavy metal leaching toxicity) of MSWIFA S/S bodies were studied in this work. The hydration characteristics and reaction mechanism were also explored in depth based on the structure properties and microstructure characterization. Ca2+, Na+, SiO42−, [Al(OH)4]-, OH− dissociated from MSWIFA and alkali activator solution chemical reaction to form the silicates, aluminates and aluminosilicates with lower polymerization, and promoted the gel hydration products formation via depolycondensation. Lower Ca/Si molar ratio was conductive to the formation of amorphous substance, compactness of matrix pore structure and immobilization properties. Compared to the hydration products including halite, sylvine, glauberite, gypsum, calcite crystal, C–S–H gel contributed much more to the pore structure and strength improvement of MSWIFA S/S bodies. These findings will provide valuable theoretical basis for MSWIFA management and resource utilization promotion.

Impact of Carrier Gas Flow Rate on the Synthesis of Monolayer WSe2 via Hydrogen-Assisted Chemical Vapor Deposition

Transition metal dichalcogenides (TMDs), particularly monolayer TMDs with direct bandgap properties, are key to advancing optoelectronic device technology. WSe2 stands out due to its adjustable carrier transport, making it a prime candidate for optoelectronic applications. This study explores monolayer WSe2 synthesis via H2-assisted CVD, focusing on how carrier gas flow rate affects WSe2 quality. A comprehensive characterization of monolayer WSe2 was conducted using OM (optical microscope), Raman spectroscopy, PL spectroscopy, AFM, SEM, XPS, HRTEM, and XRD. It was found that H2 incorporation and flow rate critically influence WSe2’s growth and structural integrity, with low flow rates favoring precursor concentration for product formation and high rates causing disintegration of existing structures. This research accentuates the significance of fine-tuning the carrier gas flow rate for optimizing monolayer WSe2 synthesis, offering insights for fabricating monolayer TMDs like WS2, MoSe2, and MoS2, and facilitating their broader integration into optoelectronic devices.

Microscale Chaotic Mixing as a Driver for Chemical Reactions in Porous Media.

Mixing-induced reactions play a key role in a large range of biogeochemical and contaminant transport processes in the subsurface. Fluid flow through porous media was recently shown to exhibit chaotic mixing dynamics at the pore scale, enhancing microscale concentration gradients and controlling mixing rates. While this phenomenon is likely ubiquitous in environmental systems, it is not known how it affects chemical reactions. Here, we use refractive index matching and laser-induced fluorescence imaging of a bimolecular redox reaction to investigate the consequence of pore scale chaotic mixing on the reaction rates. The overestimation of measured reaction rates by the classical macrodispersion model highlights the persistence of incomplete mixing on the pore scale. We show that the reaction product formation is controlled by microscale chaotic mixing, which induces an exponential increase of the mixing interface and of the reaction rates. We derive a reactive transport model that captures experimental results and predicts that chaotic mixing has a first order control on reaction rates across a large range of time scales and Péclet and Damköhler numbers. These findings provide a new framework for understanding, assessing, and predicting mixing-induced reactions and their role on the fate and mobility of environmental compounds in natural porous media.