612-17-9Relevant articles and documents
Thermodynamically Favorable Conversion of Hydrogen Sulfide into Valuable Products through Reaction with Sodium Naphthalenide
Li, Xuemin,Morrish, Rachel M.,Yang, Yuan,Wolden, Colin A.,Yang, Yongan
, p. 1508 - 1512 (2015)
Hydrogen sulfide (H2S) is an extremely hazardous chemical waste that is generated at large scale in many industries; its abatement has long been an energy-extensive and cost-ineffective liability due to the thermodynamic limitations of the selected approaches and low value of the final products, sulfur and water. Here we introduce an attractive method for H2S abatement that yields value-added products via a thermodynamically favorable process. Specifically, sodium naphthalenide (Na-NAP) is used to capture H2S to produce anhydrous Na2S nanocrystals and 1,4-dihydronaphthalene, which are important materials for batteries and liquid fuels, respectively. This multipurpose process is driven by the acid/base neutralization reaction between hydrogen cations from H2S and radical anions from naphthalenide. It is spontaneous and irreversible at ambient temperature and pressure, proceeding to completion very rapidly. Waste not, want not: The chemical waste hydrogen sulfide (H2S) is notorious for its production in many industries, harming creatures, corroding equipment, poisoning catalysts, and requiring energy-intensive and cost-ineffective abatements. Now a thermodynamically favorable process can convert H2S into value-added energy materials.
A Simple Preparation of Benzo-Fused Bicycloalkadienes from 1,3-Diene-Benzoquinone Cycloadducts
Schmid, George H.,Rabai, Jozsef
, p. 332 - 333 (1988)
Synthetic procedures are reported for the conversion of the Diels-Alder adduct of benzoquinone and both 1,3-cyclohexadiene and 1,3-cycloheptadiene to the parent hydrocarbons, 1,4-dihydro-1,4-ethanonaphthalene (benzobicyclooctadiene) and 6,7,8,9-tetrahydro-5H-5,9-ethenobenzocycloheptene (benzobicyclononadiene), respectively.The Diels-Alder adducts can be conveniently converted into the 5,8- and 1,4-dimethoxy as well as 5,8- and 1,4-diacetoxy derivatives, respectively, of these tricyclic compounds.
Synthesis and properties of 7,7-dichloro-3,4-benzobicyclo[4.1.0]heptane, its tricarbonylchromium complexes, and isomeric 7-chloro-3,4-benzobicyclo[4.1.0]heptanes
Vorogushin,Reshetova,Akhmedov,Ustynyuk,Eremenko,Nefedov,Zinin
, p. 699 - 703 (1998)
The reaction of Cr(CO)6 with 7,7-dichloro-3,4-benzobicyclo[4.1.0]heptane gave the corresponding exo- and endo-chromium tricarbonyl complexes in a ratio of 4.5 : 1 The structures of the resulting compounds were established by NMR spectroscopy, mass spectrometry, and X-ray structural analysis. Reduction of dichlorobenzobicycloheptane and its chromium tricarbonyl complexes with LiAlH4 afforded exo- and endo-7-chloro-3,4-benzobicyclo[4.1.0]heptanes in a 3.5 : 1 ratio.
Dearomatization of naphthalene: Stereoselective cis-1,4 tandem additions promoted by osmium(II)
Winemiller, Mark D.,Harman, W. Dean
, p. 7835 - 7840 (1998)
The naphthalene complex of pentaammineosmium(II) (1) reacts with four different classes of electrophiles to form 1-naphthalenium species 2-5. These η3-allyl complexes react stereospecifically with a variety of nucleophiles to form cis-1,4-dihydronaphthalene complexes. The entire reaction sequence may be performed outside a glovebox in two steps using conventional techniques.
Stereoconvergent generation of a contrasteric syn-bicyclopropylidene (=syn-Cyclopropylidenecyclopropane) by stille-like coupling
Gueney, Murat,Essiz, Selcuk,Dastan, Arif,Balci, Metin,De Lucchi, Ottorino,Sahin, Ertan,Fabris, Fabrizio
, p. 941 - 950 (2013)
Stereoisomerically pure endo- and exo-7-halo-7-(trimethylstannyl) benzonorcar-3-enes (=endo- and exo-(1-halo-1a,2,7,7a-tetrahydro-1H-cyclopropa[b] naphthalen-1-yl)trimethylstannane) 4 and 6 were selectively obtained by lithium-tin or magnesium-tin transmetalation in good yields (Scheme 2 and 3). The reaction of these compounds with copper(I) thiophene-2-carboxylate (CuTC) produced in both cases the corresponding CS-symmetric bicyclopropylidene (=cyclopropylidenecyclopropane) syn-1, a single diastereoisomer (Schemes 5 and 6). The structure of syn-1 was undoubtedly elucidated by X-ray single crystal diffraction. The coupling mechanism of the carbenoid cyclopropane is discussed (Scheme 7). Copyright
Olefination via Cu-Mediated Dehydroacylation of Unstrained Ketones
Dong, Guangbin,Xu, Yan,Zhou, Xukai
supporting information, p. 20042 - 20048 (2021/12/03)
The dehydroacylation of ketones to olefins is realized under mild conditions, which exhibits a unique reaction pathway involving aromatization-driven C-C cleavage to remove the acyl moiety, followed by Cu-mediated oxidative elimination to form an alkene between the α and β carbons. The newly adopted N′-methylpicolinohydrazonamide (MPHA) reagent is key to enable efficient cleavage of ketone C-C bonds at room temperature. Diverse alkyl- and aryl-substituted olefins, dienes, and special alkenes are generated with broad functional group tolerance. Strategic applications of this method are also demonstrated.
Dibenzoate esters of cis-tetralin-2,3-diol as analogs of (-)-epigallocatechin gallate: Synthesis and crystal structure of anticancer drug candidates
Chan, Tak-Hang,Fukumoto, Kozo,Nishioka, Takanori,Renzetti, Andrea,Rutherford, Ryan Noboru,Ura, Shinji
, p. 1085 - 1095 (2020/12/15)
(-)-Epigallocatechin gallate (EGCG), the main component of green tea extract, displays multiple biological activities. However, it cannot be used as a drug due to its low cellular absorption, instability and metabolic degradation. Therefore, there is a need to provide analogs that can overcome the limitations of EGCG. In this work, six synthetic analogs of EGCG sharing a common tetralindiol dibenzoate core were synthesized and fully characterized by 1H NMR, 13C NMR, HRMS and IR spectroscopies, and X-ray crystallography. These are (2R,3S)-1,2,3,4-tetrahydronaphthalene-2,3-diyl bis[3,4,5-tris(benzyloxy)benzoate], C66H56O10, and the analogous esters bis(3,4,5-trimethoxybenzoate), C30H32O10, bis(3,4,5-trifluorobenzoate), C24H14F6O4, bis[4-(benzyloxy)benzoate], C38H32O6, bis(4-methoxybenzoate), C26H24O6, and bis(2,4,6-trifluorobenzoate), C24H14F6O4. Structural analysis revealed that the molecular shapes of these dibenzoate esters of tetralindiol are significantly different from that of previously reported dimandelate esters or monobenzoate esters, as the acid moieties extend far from the bicyclic system without folding back over the tetralin fragment. Compounds with small fluorine substituents take a V-shape, whereas larger methoxy and benzyloxy groups determine the formation of an L-shape or a cavity. Intermolecular interactions are dominated by π-π stacking and C-H..π interactions involving the arene rings in the benzoate fragment and the arene ring in the tetrahydronaphthalene moiety. All six crystal structures are determined in centrosymmetric space groups (either P, P21/n, C2/c or I2/a).
Cytochrome p450 can epoxidize an oxepin to a reactive 2,3-epoxyoxepin intermediate: Potential insights into metabolic ring-opening of benzene
Cote, Noah A.,Fitzgerald, Ryan W.,Greenberg, Arthur,Weaver-Guevara, Holly M.
supporting information, (2020/10/18)
Dimethyldioxirane epoxidizes 4,5-benzoxepin to form the reactive 2,3-epoxyoxepin intermediate followed by very rapid ring-opening to an o-xylylene that immediately isomerizes to the stable product 1H-2-benzopyran-1-carboxaldehyde. The present study demonstrates that separate incubations of 4,5-benzoxepin with three cytochrome P450 isoforms (2E1, 1A2, and 3A4) as well as pooled human liver microsomes (pHLM) also produce 1H-2-benzopyran-1-carboxaldehyde as the major product, likely via the 2,3-epoxyoxepin. The reaction of 4,5-benzoxepin with cerium (IV) ammonium nitrate (CAN) yields a dimeric oxidized molecule that is also a lesser product of the P450 oxidation of 4,5-benzoxepin. The observation that P450 enzymes epoxidize 4,5-benzoxepin suggests that the 2,3-epoxidation of oxepin is a major pathway for the ring-opening metabolism of benzene to muconaldehyde.
Chemoenzymatic Synthesis of a Chiral Ozanimod Key Intermediate Starting from Naphthalene as Cheap Petrochemical Feedstock
Uthoff, Florian,L?we, Jana,Harms, Christina,Donsbach, Kai,Gr?ger, Harald
, p. 4856 - 4866 (2019/05/02)
Ozanimod represents a recently developed, promising active pharmaceutical ingredient (API) molecule in combating multiple sclerosis. Addressing the goal of a scalable, economically attractive, and technically feasible process for the manufacture of this drug, a novel alternative synthetic approach toward (S)-4-cyano-1-aminoindane as a chiral key intermediate for ozanimod has been developed. The total synthesis of this intermediate is based on the utilization of naphthalene as a readily accessible, economically attractive, and thus favorable petrochemical starting material. At first, naphthalene is transformed into 4-carboxy-indanone within a four-step process by means of an initial Birch reduction, followed by an isomerization of the C=C double bond, oxidative C=C cleavage, and intramolecular Friedel-Crafts acylation. The transformation of the 4-carboxy-indanone into (S)-4-cyano-1-aminoindane then represents the key step for introducing the chirality and the desired absolute S configuration. When evaluating complementary biocatalytic approaches based on the use of a lipase and transaminase, respectively, the combination of a chemical reductive amination of the 4-carboxyindanone followed by a subsequent lipase-catalyzed resolution turned out to be the most efficient route, leading to the desired key intermediate (S)-4-cyano-1-aminoindane in satisfactory yield and with excellent enantiomeric excess of 99%.
Experimental and Theoretical Studies on the Aqueous Solvation and Reactivity of SmCl2 and Comparison with SmBr2 and SmI2
Ramírez-Solís, Alejandro,Bartulovich, Caroline O.,León-Pimentel, César Iván,Saint-Martin, Humberto,Anderson, William R.,Flowers, Robert A.
supporting information, p. 13927 - 13932 (2019/10/16)
Water addition to Sm(II) has been shown to increase reactivity for both SmI2 and SmBr2. Previous work in our groups has demonstrated that this increase in reactivity can be attributed to coordination induced bond weakening enabling substrate reduction through proton-coupled electron transfer. The present work examines the interaction of water with samarium dichloride (SmCl2) and illustrates the importance of the Sm-X interaction and bond distance upon water addition critical for the reactivity of the reagent system. Born-Oppenheimer molecular dynamics simulations identify substantial variations among the reductants created in solution upon water addition to SmI2, SmBr2, and SmCl2 with the latter showing the least halide dissociation. This results in a lower water coordination number for SmCl2, creating a more powerful reducing system. As previously shown with the other SmX2-water systems, coordination-induced bond-weakening of the O-H bond of water bound to Sm(II) results in significant bond weakening. In the case of SmCl2, the bond weakening is estimated to be in the range of 83 to 88.5 kcal/mol.
