Dimsyl Sodium Research Articles

Chiral hybrid aza-oxa-terpene-based macrocycles as selective extractants for Pd(II) and Au(III)

A series of novel hybride chiral macrocyclic compounds is described. The macrocyclic core of the new compounds is decorated with monoterpene fragments and includes 2 imine nitrogens and 2 tertiary amine nitrogens of the N,N-piperazine linkage as well as several repeating ethyleneoxy units resembling those of crown ethers. The macrocyclic compounds are prepared in moderate preparative yield (16–31%) upon treatment of a mixture of bis(α-amine oximes) and α,ω-dichloro derivatives of tri-, tetra- and hexa-ethylene glycol with sodium methylsulfinylmethylide. Chemical structure of the new macrocycles was established by a complex of spectroscopic techniques and X-ray analysis. The new macrocyclic compounds demonstrate remarkable selectivity with respect to Pd(II) and Au(III) and are able to efficiently extract these metals from acidic media containing a complex mixture of alkali metals, 3d-elements and noble metals. The features of conformational behavior, the ability to form complexes and the selectivity of extraction were studied using quantum chemical calculations at the DFT level. Based on the data obtained, a consistent scheme has been formulated to explain the features of extraction and the extraction selectivity of individual macrocycles.

One-Step, Gram-Scale Synthesis of Caffeine-d 9 from Xanthine and CD3I

AbstractA one-step, gram-scale synthesis of caffeine-d 9 was achieved using xanthine and CD3I. The reaction proceeds at room temperature using dimsyl sodium as base and THF as solvent, and conducting the reaction on a 1-g scale gave caffeine and caffeine-d 9 in 77% and 86% yield, respectively, after recrystallization.

Stereoselective synthesis of 17,18-epoxy derivative of EPA and stereoisomers of isoleukotoxin diol by ring opening of TMS-substituted epoxide with dimsyl sodium.

The reaction of TMS-substituted epoxy alcohols (and derivatives) with dimsyl sodium (NaDMSO) to give 1-alkene-3,4-diols was used for the synthesis of enantiomerically enriched 17(R),18(S)-EpETE and two diastereoisomers of isoleukotoxin diol. In the synthesis of 17(R),18(S)-EpETE, the α-ethoxyethyl ether (EE) of the epoxy alcohol derived from (R)-1-TMS-1-penten-3-ol underwent reaction with NaDMSO to give the mono EE-protected 1-hexene-3,4-diol. The aldehyde obtained by hydroboration/oxidation was subjected to Wittig reaction to afford a mono EE-protected diol. The corresponding mono mesylate was prepared and subjected to epoxide ring formation to afford 17(R),18(S)-EpETE stereoselectively. Similarly, a reaction of the anti epoxy alcohol derived from (R)-1-TMS-1-octen-3-ol with NaDMSO gave the anti form of 1-nonene-3,4-diol, which was converted to 12(S),13(R)-isoleukotoxin diol through Wittig reaction. 12(R),13(R)-Isoleukotoxin diol was synthesized in a similar manner.

Synthesis of novel 4-acyl-2-amino-6-sulfanylpyridine-3,5-dicarbonitriles

An efficient one-step synthesis of novel 4-acyl-2-amino-3,5-dicarbonitrile-6-sulfanylpyridines has been developed via the reaction of 2-acyl-1,1,3,3-tetracyanopropenides with thiols in DMSO containing dimsyl sodium. 2-Amino-3,5-dicarbonitrile-6-sulfanylpyridines are the subject of considerable interest due to their wide range of pharmaceutical, biological, and medicinal applications and currently serve as a ‘privileged scaffold’ due to their potential therapeutic applications.

Interfacial properties and thermal stability of modified poly(m‐phenylene isophthalamide) thin films

Poly(m‐phenylene isophthalamide) (PMIA) is a resistant to high temperatures and chemically stable engineering material. The application as coatings and membranes, however, is limited by its poor interaction with other materials. In this report, we describe the molecular modification of PMIA through reaction with dimsyl sodium and 2‐iodine‐1‐ethanol. The substitution of 58% of amide hydrogen by ethanol (etOH) groups produces a material (MPMIA) able to develop regularly structured films on silicon substrate. The morphology of the films is dependent on the ionic strength of the precursory solution. MPMIA starts a degradation process by losing the etOH group. MPMIA has a better affinity with poly(p‐cresolformaldehyde) than with a pristine one, increasing the range of composition in which thermal stability and miscibility are observed. Thin films of these blends have different morphologies that vary from nanometric porous to two‐phase microstructured grains, according to the composition. Copyright © 2012 John Wiley & Sons, Ltd.

2-Isoxazolines with an electron-acceptor substituent at C(5) in reactions with nucleophilic reagents

Depending on the substituent at position 5 of the heterocycle, reaction of 2-isoxazolines with K-selectride, molybdenum hexacarbonyl, dimsyl sodium, and butyl lithium gave 1,3-cyclo-decomposition, aromatization of the isoxazoline ring, or reduction of the functional groups in the substituted isoxazolines.

Sodium Methylsulfinylmethylide: A Versatile Reagent

Sodium methylsulfinylmethylide (sodium dimsylate, dimsylsodium), introduced by Corey and Chaykovsky, [1] has found widespread use [2] in organic synthesis because of its strong basic character, nucleophilicity and its use for the introduction of methylsulfinylmethyl group. It is ­conveniently prepared1 by heating finely powered sodium hydride in an excess of anhydrous DMSO under nitrogen at about 70 °C until hydrogen evolution stops, resulting in a clear solution. Sodium amide can also be used as the base. [3]

Regio‐ and Stereoselective Stevens Rearrangement of Benzyltetrahydroprotoberberinium Salts

Abstract8‐(Arylmethyl)berbines are conveniently obtained through a Stevens rearrangement of the corresponding N‐arylmethylberbinium salts with sodium methylsulfinylmethylide in DMSO. This procedure has provided two new nonnatural 8‐benzylcanadines stereoselectively, without competition from the Hofmann elimination. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Transformation of acetalized polyhyroxyketene thioacetal in acid-alcohol medium

2,3:4,5-Di-O-cyclohexylidene-L-arabinose diethyl dithioacetal was treated with sodium methylsulfinylmethylide to prepare a novel compound, 4,5-cyclohexylidene-2-deoxy-L-erythro-pent-1-enose diethyl dithioacetal. The product undergoes a series of transformations in anhydrous ethanol in the presence of p-toluenesulfonic acid: alcoholysis of the cyclohexylidene protection, elimination of water, migration of the double bond, formation of an acyclic allyl cation, elimination of the ethylthio group, formation of a cyclic allyl cation, migration of the mercapto group from C1 to C3,addition of alcohol, and formation of an acetalized lactone. The latter was acetalized to obtain a diastereomeric mixture of 5-O-acetyl-2-deoxy-3-S-ethyl-L-threo- and -erythro-pentono-1,4-lactones.

Dimsyl Anion Mediated Tandem Fragmentation Cyclization Reactions of Alkenoyl Ketenedithioacetals: A Facile Synthesis of Substituted 2,3-Dihydro-4H-thiopyran-4-ones

Dimsyl sodium induced anionic ring cleavage of 1-(1,3-dithiolane-2-ylidene)-4-aryl-3-butene-2-ones followed by intramolecular cyclisation of the intermediate thiolate anion gave 2-aryl, 6-(vinylsulfanyl)-2,3-dihydro-4H-thiopyran-4-ones in good yields.

A Serendipitous Synthesis of 8-Dimsyl-2′-deoxyguanosine

A serendipitous synthesis of 8-dimsyl-dG (2) has been achieved along with the known 8-benzyloxy-dG (3) in a nucleophilic substitution reaction of 8-bromo-dG (1) with in situ generated dimsyl and benzyloxy sodium. Compound 3 was directly converted into the mutagenic oxidative DNA damage product, 8-oxo-dGTP (4).

Azulene-annulated tricyclo[4.3.1.01,6]deca-2,4,7-triene derivatives and their anions. A novel cycloheptatriene-norcaradiene valence isomerization in the azulene-annulated tricyclo[4.3.1.01,6]deca-2,4,7-triene ring system

10-Trifluoroacetyl-11,11a-dihydro-4aH-4a,11a-methanoindeno[1,2-a]azulene 18 and methyl {11,11a-dihydro-4aH-4a,11a-methanoindeno[1,2-a]azulen-10-yl}carboxylate 19 are synthesized starting from the azulene-annulation reaction of 2H-cyclohepta[b]furan-2-one with the pyrrolidine enamine derived from tricyclo[4.3.1.01,6]dec-3-en-8-one. The 13C NMR spectra at various temperatures reveal that compound 18 exists in a norcaradiene structure, while compound 19 is in equilibrium between norcaradiene and cycloheptatriene structures. The latter compound is the first example of a cycloheptatriene, which experiences a forced shortening of the C6–C11 distance by a three carbon chain.† The facile valence isomerization of compound 19 is ascribed to the interaction of the lowest unoccupied molecular orbital (LUMO) of the Walsh orbital of cyclopropane and the highest occupied molecular orbital (HOMO) of the methoxycarbonylazulene, and the interaction occurs effectively as to weaken the basal C6–C11 bond of the cyclopropane ring, as compared to that in compound 18 involving an azulene nucleus bearing the more electron-withdrawing trifluoroacetyl group. The hydrogen–deuterium exchange reaction of compounds 18 and 19 in MeONa–MeOD occurs stereospecifically to give 12-exo-deuterated products (exo to the bridge methylene), respectively. Marked spectroscopic differences between the anions 30 and 31, which are derived from compounds 18 and 19 by treatment with [2H5]dimsyl sodium in [2H6]DMSO, respectively, are also observed: the anionic charge in the former is not delocalized over the trifluoroacetylazulene nucleus, while that in the latter is delocalized over the methoxycarbonylazulene nucleus. The thermal rearrangement of the anion generated from compound 19 is also observed to result in the formation of 11-methoxycarbonylazuleno[1,2-a]azulene. Furthermore, the Diels–Alder reaction of the tricyclo[4.3.1.01,6]deca-2,4,7-triene (methanoindeno[1,2-a]azulene) ring system in compounds 18 and 19 has been studied as well.

Preparation of novel (1-->3)-beta-D-glucans having reducing glucose side chains.

Novel (1-->3)-beta-D-glucans (GPBCD, GPECD, GP6CD, and GP3CD) having reducing glucose side chains were prepared from a linear (1-->3)-beta-D-glucan (curdlan: CD) with halogeno glucose isopropylidene derivatives in dimethyl sulfoxide containing dimsyl sodium, followed by treatment with 40% trifluoroacetic acid to remove protecting isopropylidene groups. The side chain glucose moiety was linked or directly or through a spacer at various positions except for its anomeric carbon.

Physical properties of methylcelluloses in relation with the conditions for cellulose modification

Water-soluble methylcellulose (MC) samples were synthesized by a new homogeneous reaction using DMAc/LiCl as solvent, a dimsyl sodium solution as activator and CH 3 as alkylating reagent. Different degrees of substitution were obtained (0.9 < DS < 2.2). A commercial MC ( DS = 1.7) was also studied. The structural characterization of the samples was carried out using 13C-NMR and h.p.l.c. measurements. Rheological and steric exclusion chromatography studies in the dilute regime were performed as a function of the temperature and the properties of the samples were compared. According to the DS value, two different behaviours were observed. For DS > 1.5, interactions occur for T > 45 ° C. If DS < 1.5 there is no clear evidence for aggregation.

Homogeneous alkylation of cellulose in lithium chloride/dimethyl sulfoxide solvent with dimsyl sodium activation. A proposal for the mechanism of cellulose dissolution in LiCl/Me 2SO

Homogeneous alkylation of cellulose in lithium chloride/dimethyl sulfoxide solvent with dimsyl sodium activation. A proposal for the mechanism of cellulose dissolution in LiCl/Me 2SO

Monitoring reaction exotherms in pilot scale batch reactors

Abstract A method is described in which bench scale heat flow calorimetry data can be used to monitor a chemical reaction at the pilot scale level. A reaction involving dimsyl sodium formation and ester coupling is used as an example to illustrate the methodology. The theoretical and practical considerations for such analysis are discussed both at the laboratory and pilot scales.

ChemInform Abstract: Two‐Fold Crotonic Condensation of 1,1‐Bisacylcyclopropanes Under the Conditions of the Wittig Reaction. Simple Synthesis of Spirocyclopropanecyclooctatrienones.

AbstractIn the presence of dimsyl sodium the reaction between 1,1‐diacetylcyclopropane (I) and the ylide generated from the phosphonium bromide (II) affords (III) or (IV) depending on the order of addition and on the molar ratios of the reactants.

ChemInform Abstract: Cleavage of Isoxazolines with Dimsyl Sodium.

ChemInformVolume 19, Issue 23 Preparative Organic Chemistry ChemInform Abstract: Cleavage of Isoxazolines with Dimsyl Sodium. F. A. LAKHVICH, F. A. LAKHVICH Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this authorT. V. YANKOVA, T. V. YANKOVA Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this authorE. V. KOROLEVA, E. V. KOROLEVA Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this authorA. A. AKHREM, A. A. AKHREM Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this author F. A. LAKHVICH, F. A. LAKHVICH Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this authorT. V. YANKOVA, T. V. YANKOVA Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this authorE. V. KOROLEVA, E. V. KOROLEVA Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this authorA. A. AKHREM, A. A. AKHREM Inst. bioorg. khim. AN Belorusskoi SSR, Minsk 220600Search for more papers by this author First published: June 7, 1988 https://doi.org/10.1002/chin.198823105Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue23June 7, 1988 RelatedInformation

Cleavage of isoxazolines by dimsylsodium

Cleavage of isoxazolines by dimsylsodium

Synthetic Approaches to cularines. III. Nucleophilic addition and substitution

AbstractAttempts to induce the formation of the dibenzoxepine ring of cularine compounds by generating an electron‐deficient system in ring C of an 8‐hydroxybenzylisoquinoline met with failure. Attack by C‐8 phenol on a “p‐quinone methide” intermediate afforded benzofurans 16, which it has been suggested are intermediates in the biogenesis of quettamines. Among the nucleophilic substitution reactions tried, only that based on a phenoxide attack on a benzyne intermediate (generated by dimsyl sodium treatment of a 2′‐bromo‐8‐hydroxybenzylisoquinoline) afforded the dibenzoxepine nucleus of tetradehydrocularines 25 and 27. Competing N‐attack afforded the indolizine skeleton present in 24 and 26. From compounds 25 and 27, the corresponding cularines, cularimines and oxocularines were obtained.