34837-55-3Relevant articles and documents
Structural isomerism in (p-XC6H4)SeCl3 and (p-XC6H4)SeBr3 (X = F, Cl) compounds. Co-crystallisation of cis- and trans-dimeric forms of (p-ClC6H 4)SeCl2(μ-Cl)2(p-ClC6H4)SeCl2. A new structural modification for the "phSeBr" reagent, Ph2Se2Br2, containing an elongated Se-Se bond
Barnes, Nicholas A.,Godfrey, Stephen M.,Ollerenshaw, Ruth T. A.,Khan, Rana Z.,Pritchard, Robin G.
, p. 14583 - 14593 (2012)
A series of di(para-halophenyl)diselenides, (p-XC6H 4)2Se2 (X = F, Cl) have been reacted with three equivalents of SO2Cl2 or Br2, leading to the formation of selenium(iv) RSeX3 compounds. The structures of (p-FC6H4)SeX3 (X = Cl, Br) have been determined, and both exhibit a dimeric RSeX2(μ-X) 2RSeX2 structure consisting of two "saw-horse" (p-FC6H4)SeX3 units linked by two halide bridges, with an overall square pyramidal geometry at selenium. In both structures all the selenium and halogen atoms are planar, with both aryl rings located on the same side of the Se2X6 plane (cis-isomer). The structure of (p-ClC6H4)SeCl3 also adopts a planar dimeric structure, however both cis- and trans-dimeric molecules are co-crystallised in the unit cell. In contrast, the structure of (p-ClC 6H4)SeBr3 adopts a folded cis-dimeric structure due to steric constraints. Secondary Se...X interactions to the "vacant" sixth coordination site at selenium are a feature of most of these structures, but are most prominent in the folded structure of (p-ClC 6H4)SeBr3. A re-examination of the PhSeBr/PhSeBr3 system resulted in the isolation of crystals of a second structural form of "PhSeBr". The structure of Ph 2Se2Br2 consists of two PhSeBr units linked by an elongated Se-Se bond of 2.832(4) A, and longer secondary Se...Br interactions of 3.333(4) A to form a chain structure. Further weak Se...Br and Br...Br interactions are present, which form loosely linked rippled sheets of selenium and bromine atoms, similar to the sheets observed for the tetrameric form, Ph4Se4Br4.
4-Amino-2-(substituted methyl)-2-butenoic acids: Substrates and potent inhibitors of γ-aminobutyric acid aminotransferase
Silverman,Durkee,Invergo
, p. 764 - 770 (1986)
4-Amino-2-(substituted methyl)-2-butenoic acids, where X (the substituted group) = F, Cl, OH, are synthesized from Cbz-protected tert-butyl 4-aminobutanoate. Successive substitutions at the α-carbon by phenylseleno and hydroxymethyl groups, followed by elimination of the selenoxide and halide substitution at the hydroxymethyl group, afford the compounds in good yields. An unexpected degree of stereoselectivity is observed in the selenoxide elimination step, which yields the desired E isomer as the sole product. These compounds complement two previously reported series of compounds (Silverman, R.B.; Levy, M.A. Biochem. Biophys. Res. Commun. 1980, 95, 250-255; J. Biol. Chem. 1981, 256, 11565-11568) and are used in an approach to map a section of the active site of γ-aminobutyric acid aminotransferase (GABA-T). None of these compounds is a time-dependent inactivator of GABA-T, but all are potent competitive reversible inhibitors; the hydroxy compound has a K(i) value of 5 μM. That these compounds are not inactivators suggests that either elimination of X does not occur or that there is no active site nucleophile in the appropriate position for reaction following elimination. With use of the fluoro analogue, enzyme-catalyzed fluoride ion release is demonstrated, indicating that elimination does occur. Unlike the previous two series of compounds (op. cit.) in which exclusive elimination occurs when the substituent is a halogen but exclusive transamination prevails for the hydroxyl-substituted analogues, in the series described here, the fluoro analogue gives a 4:1 ratio of elimination to transamination. This suggests that the 2,3-double bond stabilizes the product of azallylic isomerization of the Schiff base between the fluoro compound and pyridoxal phosphate. The results described here indicate that the design of a mechanism-based inactivator for GABA-T should not be based on electrophile generation near the 2-position of enzyme-bound GABA. Furthermore, substitution of an inhibitor with a 2-hydroxymethyl group (or other hydrogen-bonding substituent) and a 2,3-double bond may lend auspicious binding properties to the molecule for GABA-T.
Diastereoselective Manipulations of Bicyclo[m.1.0]alkane Derivatives. 4. Reactions of Nucleophiles with Bicyclo[m.1.0]alk-3-en-2-ones
Mash, Eugene A.,Gregg, Timothy M.,Baron, James A.
, p. 8513 - 8521 (1997)
Enantiomerically enriched bicyclo[m.1.0]alk-3-en-2-ones possessing 8-, 12-, and 15-membered rings were prepared and subjected to additions of nucleophiles. 1,2-Additions of n-butyllithium were highly diastereoselective for all cyclopropyl enones examined. Reactions of (Z)-bicyclo[6.1.0]non-3-en-2-one and (E)-bicyclo[13.1.0]hexadec-3-en-2-one with dimethyloxosulfonium methylide were highly diastereoselective, while reaction of (E)-bicyclo[10.1.0]tridec-3-en-2-one with this reagent was not diastereoselective. In contrast, 1,4-additions of lithium diorganocuprates were highly diastereoselective for the 8- and 12-membered enones but were not diastereoselective for the 15-membered enone. All reactions were chemically efficient. The diastereoselectivities observed for 1,2-additions, which are thought to involve early transition states, can be rationalized by consideration of the low-energy conformations of each cyclopropyl enone. The diastereoselectivities observed for 1,4-additions, which may involve late transition states, do not correlate simply with the lowest energy conformations of these enones.
A greener protocol for the synthesis of phosphorochalcogenoates: Antioxidant and free radical scavenging activities
Mailahn, Daniela H.,Iarocz, Lucas E.B.,Nobre, Patrick C.,Perin, Gelson,Sinott, Airton,Pesarico, Ana Paula,Birmann, Paloma T.,Savegnago, Lucielli,Silva, Márcio S.
, (2020/12/07)
In this contribution, a metal- and base-free protocol has been developed for the synthesis of phosphorochalcogenoates (Se and Te) by using DMSO as solvent at 50 °C. A variety of phosphorochalcogenoates were prepared from diorganyl dichalcogenides and H-phosphonates, leading to the formation of a Chal-P(O) bond, in a rapid procedure with good to excellent yields. A full structural elucidation of products was accessed by 1D and 2D NMR, IR, CGMS, and HRMS analyses, and a stability evaluation of the phosphorochalcogenoates was performed for an effective operational description of this simple and feasible method. Typical 77Se{1H} (δSe = 866.0 ppm), 125Te{1H} (δTe = 422.0 ppm) and 31P{1H} (δP = ?1.0, ?13.0 and ?15.0 ppm) NMR chemical shifts were imperative to confirm the byproducts, in which this stability study was also important to select some products for pharmacological screening. The phosphorochalcogenoates were screened in vitro and ex vivo tests for the antioxidant potential and free radical scavenging activity, as well as to investigation toxicity in mice through of the plasma levels of markers of renal and hepatic damage. The pharmacological screening of phosphorochalcogenoates indicated that compounds have antioxidant propriety in different assays and not changes plasma levels of markers of renal and hepatic damage, with excision of 3g compound that increased plasma creatinine levels and decreased plasma urea levels when compared to control group in the blood mice. Thus, these compounds can be promising synthetic antioxidants that provide protection against oxidative diseases.
Synthesis method of selenium-containing isochroman compound
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Paragraph 0046; 0057, (2021/05/29)
The invention discloses a synthesis method of a selenium-containing isochroman compound. The synthesis method comprises the following steps: under the protection of nitrogen, adding N-phenylseleno saccharin (NPSSac) into a reactor, then adding dichloromethane to completely dissolve the N-phenylseleno saccharin, adding a 1-[(cinnamoxy) methyl]-3, 4, 5-trimethoxy benzene compound and boron trifluoride diethyl etherate after the N-phenylseleno saccharin is completely dissolved, stirring at 20-60 DEG C for 2-6 hours until the reaction is complete, and after the reaction is finished, quenching, extracting, combining organic phases, drying, concentrating, separating and purifying to obtain the selenium-containing isochroman compound. The synthesis method disclosed by the invention is relatively easy to operate, mild in reaction condition, relatively high in yield, environment-friendly and suitable for large-scale industrial production.
Synthesis method of 2-benzoxepin compound
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Paragraph 0045; 0054; 0057; 0066, (2021/05/29)
The invention discloses a synthesis method of a 2-benzoxepin compound. The method comprises the following specific steps: under the protection of nitrogen, adding N-phenylseleno-phthalimide into a reactor, then adding anhydrous dichloromethane to dissolve the N-phenylseleno-phthalimide, then adding a 1-[(cinnamyl) methyl]-3, 4, 5-trimethoxybenzene compound, taking zinc chloride as a catalyst, reacting at room temperature, adding saturated sodium bicarbonate for quenching after the reaction is finished, extracting by dichloromethane, combining organic phases, drying by anhydrous magnesium sulfate, concentrating under reduced pressure, and performing silica gel rapid chromatographic purification by thin-layer chromatography silica gel to obtain the 2-benzoxepin compound. The method is simple in reaction operation, mild in reaction condition, relatively high in yield, environment-friendly and suitable for large-scale industrialized production.
Synthesis method of isochroman compound
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Paragraph 0046; 0055; 0060; 0069; 0073; 0082, (2021/05/15)
The invention discloses a synthesis method of an isochroman compound, which comprises the following steps of adding dichloromethane and phosphorus tribromide into 3, 4, 5-trimethoxy benzyl alcohol, and reacting to obtain 1-bromomethyl-3, 4, 5-trimethoxy benzene, adding tetrahydrofuran, cinnamyl alcohol, sodium hydride and 1-bromomethyl-3, 4, 5-trimethoxybenzene into a reactor, and reacting to obtain 1-[(cinnamyl oxy)methyl]-3, 4, 5-trimethoxybenzene, adding cyanuric acid into a reactor containing a potassium hydroxide aqueous solution to react, dropwise adding a silver nitrate aqueous solution, and reacting to obtain silver isocyanurate, adding silver isocyanurate, phenyl selenium bromide and anhydrous dichloromethane into a reactor, and reacting to obtain N, N, N-triphenyl seleno isocyanurate, reacting N, N, N-triphenyl seleno isocyanurate, dichloromethane, boron trifluoride diethyl etherate and a 1-[(cinnamyl oxy)methyl]-3, 4, 5-trimethoxybenzene compound to obtain a target product. The method is simple in reaction operation, mild in reaction condition, relatively high in yield and environment-friendly.
Remarkable alkene-to-alkene and alkene-to-alkyne transfer reactions of selenium dibromide and phsebr. Stereoselective addition of selenium dihalides to cycloalkenes
Potapov, Vladimir A.,Musalov, Maxim V.,Kurkutov, Evgeny O.,Yakimov, Vladimir A.,Khabibulina, Alfiya G.,Musalova, Maria V.,Amosova, Svetlana V.,Borodina, Tatyana N.,Albanov, Alexander I.
, (2020/01/13)
The original goal of this research was to study stereochemistry of selenium dihalides addition to cycloalkenes and properties of obtained products. Remarkable alkene-to-alkene and alkene-to-alkyne transfer reactions of selenium dibromide and PhSeBr were discovered during this research. The adducts of selenium dibromide with alkenes or cycloalkenes easily exchange SeBr2 with other unsaturated compounds, including acetylenes, at room temperature, in acetonitrile. Similar alkene-to-alkene and alkene-to-alkyne transfer reactions of the PhSeBr adducts with alkenes or cycloalkenes take place. The supposed reaction pathway includes the selenium group transfer from seleniranium species to alkenes or alkynes. It was found that the efficient SeBr2 and PhSeBr transfer reagents are Se(CH2CH2Br)2 and PhSeCH2CH2Br, which liberate ethylene, leading to a shift in equilibrium. The regioselective and stereoselective synthesis of bis(E-2-bromovinyl) selenides and unsymmetrical E-2-bromovinyl selenides was developed based on the SeBr2 and PhSeBr transfer reactions which proceeded with higher selectivity compared to analogous addition reactions of SeBr2 and PhSeBr to alkynes under the same conditions.
Progress toward a Convergent, Asymmetric Synthesis of Jervine
De Jesús Cruz, Pedro,Johnson, Jeffrey S.,Zavesky, Blane P.
supporting information, (2020/04/30)
Progress toward a convergent approach for the enantioselective synthesis of the Veratrum alkaloid jervine is presented. The two requisite fragments were stereoselectively and efficiently fashioned from economical and readily available reagents. Key reactions include (a) a highly diastereoselective Ireland-Claisen rearrangement to establish the necessary cis-relationship between the amine and methyl group on the tetrahydrofuran E-ring; (b) a diastereoselective selenoetherification reaction that enabled the assembly of the D/E oxaspiro[4.5]decene in the needed configuration; and (c) an enzymatic desymmetrization of an abundant achiral diol en route to a key four-carbon building block as a practical alternative to a protected Roche ester reduction.
Recyclable 1,2-bis[3,5-bis(trifluoromethyl)phenyl]diselane-catalyzed oxidation of cyclohexene with H2O2: A practical access to trans-1,2-cyclohexanediol
Yu, Lei,Wang, Jun,Chen, Tian,Wang, Yuguang,Xu, Qing
, p. 652 - 656 (2014/08/05)
1,2-Bis[3,5-bis(trifluoromethyl)phenyl]diselane-catalyzed oxidation of cyclohexene by hydrogen peroxide affords a quick, clean and practical access to the important compound trans-1,2-cyclohexanediol under mild conditions. The highly atom-economic properties, clean procedures, high reaction concentration, short reaction time, mild conditions and eco-friendly, recyclable and low loading catalysts facilitate this methodology for possible future practical industrial production. Copyright
