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Organic Letters Aug 2018A facile, one-pot synthetic method for the synthesis of 5-methylene-2-pyrrolones (5MPs) from inexpensive furfuryl acetate is described. Bromine oxidation and trapping of...
A facile, one-pot synthetic method for the synthesis of 5-methylene-2-pyrrolones (5MPs) from inexpensive furfuryl acetate is described. Bromine oxidation and trapping of the in situ generated 1,4-dicarbonyl compound by a primary amine provided the corresponding 5MPs in 50-69% yield.
Topics: Bromine; Cyclization; Furans; Oxidation-Reduction; Pyrroles
PubMed: 30063360
DOI: 10.1021/acs.orglett.8b02030 -
Current Opinion in Biotechnology Apr 2022The pressing need for novel bioproduction approaches faces a limitation in the number and type of molecules accessed through synthetic biology. Halogenation is widely... (Review)
Review
The pressing need for novel bioproduction approaches faces a limitation in the number and type of molecules accessed through synthetic biology. Halogenation is widely used for tuning physicochemical properties of molecules and polymers, but traditional halogenation chemistry often lacks specificity and generates harmful by-products. Here, we pose that deploying synthetic metabolism tailored for biohalogenation represents an unique opportunity towards economically attractive and environmentally friendly organohalide production. On this background, we discuss growth-coupled selection of functional metabolic modules that harness the rich repertoire of biosynthetic and biodegradation capabilities of environmental bacteria for in vivo biohalogenation. By rationally combining these approaches, the chemical landscape of living cells can accommodate bioproduction of added-value organohalides which, as of today, are obtained by traditional chemistry.
Topics: Bacteria; Biodegradation, Environmental; Halogenation; Synthetic Biology
PubMed: 34954625
DOI: 10.1016/j.copbio.2021.11.009 -
Chemosphere May 2020Brominated organic compounds (BOCs), abundant in Nature, originate from its own sources or anthropogenic activity. Many of these compounds are harmful and constitute a... (Review)
Review
Brominated organic compounds (BOCs), abundant in Nature, originate from its own sources or anthropogenic activity. Many of these compounds are harmful and constitute a serious threat, therefore it is important to study and understand their behavior and fate. In situ, BOCs undergo various chemical and biochemical reactions through distinctive mechanistic pathways. However, breaking C-Br specific bond is a crucial step in the transformation of brominated organic compounds. Understanding the mechanisms of debromination can be substantially enhanced by studying Br isotope effects. In this Mini-review we provide overlook of existing experimental techniques for Br isotope analysis, discuss Br kinetic isotope effects measured for selected chemical and biochemical reactions in the light of underlying reaction mechanisms, and review the outcome from computational study of performed to provide more insightful interpretation of observed findings.
Topics: Bromine; Halogenation; Isotopes; Kinetics
PubMed: 31918087
DOI: 10.1016/j.chemosphere.2019.125746 -
Chemistry (Weinheim An Der Bergstrasse,... Apr 2020Pd-mediated reactions have emerged as a powerful tool for the site-selective and bioorthogonal late-stage diversification of amino acids, peptides and related compounds.... (Review)
Review
Pd-mediated reactions have emerged as a powerful tool for the site-selective and bioorthogonal late-stage diversification of amino acids, peptides and related compounds. Indole moieties of tryptophan derivatives are susceptible to C H-activation, whereas halogenated aromatic amino acids such as halophenylalanines or halotryptophans provide a broad spectrum of different functionalisations. The compatibility of transition-metal-catalysed cross-couplings with functional groups in peptides, other biologically active compounds and even proteins has been demonstrated. This Review primarily compiles the application of different cross-coupling reactions to modify halotryptophans, halotryptophan containing peptides or halogenated, biologically active compounds derived from tryptophan. Modern approaches use regio- and stereoselective biocatalytic strategies to generate halotryptophans and derivatives on a preparative scale. The combination of bio- and chemocatalysis in cascade reactions is given by the biocompatibility and bioorthogonality of Pd-mediated reactions.
Topics: Amino Acids; Catalysis; Halogenation; Peptides; Tryptophan
PubMed: 31544296
DOI: 10.1002/chem.201903756 -
Angewandte Chemie (International Ed. in... Jun 2022(Hetero)arylsulfur compounds where the S atom is in the oxidation state VI represent a large percentage of the molecular functionalities present in organic chemistry.... (Review)
Review
(Hetero)arylsulfur compounds where the S atom is in the oxidation state VI represent a large percentage of the molecular functionalities present in organic chemistry. More specifically, (hetero)aryl-S fluorides have recently received enormous attention because of their potential as chemical biology probes, as a result of their reactivity in a simple, modular, and efficient manner. Whereas the synthesis and application of the level 1 fluorination at S atoms (sulfonyl and sulfonimidoyl fluorides) have been widely studied and reviewed, the synthetic strategies towards higher levels of fluorination (levels 2 to 5) are somewhat more limited. This Minireview evaluates and summarizes the progress in the synthesis of highly fluorinated aryl-S compounds at all levels, discussing synthetic strategies, reactivity, the advantages and disadvantages of the synthetic procedures, the proposed mechanisms, and the potential upcoming opportunities.
Topics: Fluorides; Halogenation; Oxidation-Reduction
PubMed: 35303387
DOI: 10.1002/anie.202200904 -
Physiology (Bethesda, Md.) Sep 2021The halogens chlorine (Cl) and bromine (Br) are highly reactive oxidizing elements with widespread industrial applications and a history of development and use as... (Review)
Review
The halogens chlorine (Cl) and bromine (Br) are highly reactive oxidizing elements with widespread industrial applications and a history of development and use as chemical weapons. When inhaled, depending on the dose and duration of exposure, they cause acute and chronic injury to both the lungs and systemic organs that may result in the development of chronic changes (such as fibrosis) and death from cardiopulmonary failure. A number of conditions, such as viral infections, coexposure to other toxic gases, and pregnancy increase susceptibility to halogens significantly. Herein we review their danger to public health, their mechanisms of action, and the development of pharmacological agents that when administered post-exposure decrease morbidity and mortality.
Topics: Animals; Bromine; Chlorine; Halogens; Humans; Lung
PubMed: 34431415
DOI: 10.1152/physiol.00004.2021 -
Annals of the New York Academy of... Nov 2020Owing to a high-volume industrial usage of the halogens chlorine (Cl ) and bromine (Br ), they are stored and transported in abundance, creating a risk for accidental or... (Review)
Review
Owing to a high-volume industrial usage of the halogens chlorine (Cl ) and bromine (Br ), they are stored and transported in abundance, creating a risk for accidental or malicious release to human populations. Despite extensive efforts to understand the mechanisms of toxicity upon halogen exposure and to develop specific treatments that could be used to treat exposed individuals or large populations, until recently, there has been little to no effort to determine whether there are specific features and or the mechanisms of halogen exposure injury in newborns or children. We established a model of neonatal halogen exposure and published our initial findings. In this review, we aim to contrast and compare the findings in neonatal mice exposed to Br with the findings published on adult mice exposed to Br and the neonatal murine models of bronchopulmonary dysplasia. Despite remarkable similarities across these models in overall alveolar architecture, there are distinct functional and apparent mechanistic differences that are characteristic of each model. Understanding the mechanistic and functional features that are characteristic of the injury process in neonatal mice exposed to halogens will allow us to develop countermeasures that are appropriate for, and effective in, this unique population.
Topics: Animals; Animals, Newborn; Bromine; Bronchopulmonary Dysplasia; Child; Chlorine; Humans; Infant, Newborn; Lung; Lung Injury; Mice
PubMed: 32738176
DOI: 10.1111/nyas.14445 -
Environmental Science & Technology Mar 2021Chemical disinfectants employed in water and wastewater treatment can produce a variety of transformation products, including carbonyl compounds (e.g., saturated and...
Chemical disinfectants employed in water and wastewater treatment can produce a variety of transformation products, including carbonyl compounds (e.g., saturated and unsaturated aldehydes and ketones). Experiments conducted under conditions relevant to chlorination at drinking water treatment plants and residual chlorine application in distribution systems indicate that α,β-unsaturated carbonyl compounds readily react with free chlorine and free bromine over a wide pH range but react slowly with combined chlorine (i.e., NHCl). For nearly all of the 11 α,β-unsaturated carbonyl compounds studied, the apparent second-order rate constants for the reaction with free chlorine increased in a linear manner with hypochlorite (OCl) concentrations, yielding species-specific second-order rate constants for the reaction with OCl ranging from 0.21 to 12 M s. Predictions based on the second-order rate constants indicate that a substantial fraction (i.e., >60%) of several of the more prominent α,β-unsaturated carbonyls (e.g., acrolein, crotonaldehyde) will be transformed to an appreciable extent in distribution systems by free chlorine. Products from the reaction of chlorine with acrolein, crotonaldehyde, and methyl vinyl ketone were tentatively identified using nuclear magnetic resonance (NMR) and gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC-HRT-MS). These products lacked unsaturated carbons and, in some cases, contained multiple halogens.
Topics: Bromine; Chlorine; Disinfectants; Kinetics; Water Pollutants, Chemical; Water Purification
PubMed: 33565865
DOI: 10.1021/acs.est.0c07660 -
Applied Microbiology and Biotechnology Nov 2021Fluorinated compounds are widely used in the fields of molecular imaging, pharmaceuticals, and materials. Fluorinated natural products in nature are rare, and the... (Review)
Review
Fluorinated compounds are widely used in the fields of molecular imaging, pharmaceuticals, and materials. Fluorinated natural products in nature are rare, and the introduction of fluorine atoms into organic compound molecules can give these compounds new functions and make them have better performance. Therefore, the synthesis of fluorides has attracted more and more attention from biologists and chemists. Even so, achieving selective fluorination is still a huge challenge under mild conditions. In this review, the research progress of enzymatic synthesis of fluorinated compounds is summarized since 2015, including cytochrome P450 enzymes, aldolases, fluoroacetyl coenzyme A thioesterases, lipases, transaminases, reductive aminases, purine nucleoside phosphorylases, polyketide synthases, fluoroacetate dehalogenases, tyrosine phenol-lyases, glycosidases, fluorinases, and multienzyme system. Of all enzyme-catalyzed synthesis methods, the direct formation of the C-F bond by fluorinase is the most effective and promising method. The structure and catalytic mechanism of fluorinase are introduced to understand fluorobiochemistry. Furthermore, the distribution, applications, and future development trends of fluorinated compounds are also outlined. Hopefully, this review will help researchers to understand the significance of enzymatic methods for the synthesis of fluorinated compounds and find or create excellent fluoride synthase in future research.Key points• Fluorinated compounds are distributed in plants and microorganisms, and are used in imaging, medicine, materials science.• Enzyme catalysis is essential for the synthesis of fluorinated compounds.• The loop structure of fluorinase is the key to forming the C-F bond.
Topics: Aldehyde-Lyases; Catalysis; Fluorine; Halogenation; Transaminases
PubMed: 34625820
DOI: 10.1007/s00253-021-11608-0 -
Molecules (Basel, Switzerland) Nov 2022A series of new symmetrical 2,5-dialkyl-1,3,4-oxadiazoles containing substituted alkyl groups at the terminal positions with substituents, such as bromine,...
A series of new symmetrical 2,5-dialkyl-1,3,4-oxadiazoles containing substituted alkyl groups at the terminal positions with substituents, such as bromine, isopropyloxycarbonylmethylamino, and carboxymethylamino, were successfully synthesized. The developed multistep method employed commercially available acid chlorides differing in alkyl chain length and terminal substituent, hydrazine hydrate, and phosphorus oxychloride. The intermediate bromine-containing 2,5-dialkyl-1,3,4-oxadiazoles were easily substituted with diisopropyl iminodiacetate, followed by hydrolysis in aqueous methanol solution giving the corresponding 1,3,4-oxadiazoles bearing carboxymethylamino substituents. The structure of all products was confirmed by conventional spectroscopic methods including H NMR, C NMR, and HRMS.
Topics: Oxadiazoles; Bromine; Magnetic Resonance Spectroscopy
PubMed: 36431787
DOI: 10.3390/molecules27227687