Reaction of selenium and tellurium halides with propargyl alcohols. The regio‐ and stereoselectivity of addition to the triple bond

Braverman, S.; Cherkinsky, M.; Jana, Ranjan; Kalendar, Yuliya; Sprecher, Milon

doi:10.1002/poc.1729

Cited by 26 publications

(23 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to the above, were our findings in the reaction of selenium dihalides with homopropargyl alcohol. 16 Although some loss of stereo-and regioselectivity was observed, Z-anti-Markovnikov adducts 4 were chromatographically isolated as major products and underwent oxidation with H 2 O 2 to the corresponding fivemembered spiroselenuranes 5 with exocyclic double bonds (Scheme 3). In an alternative approach to the preparation of spirodioxaselenuranes, we have found that but-2-yn-1,4-diol smoothly reacts with selenium dihalides in a completely stereospecific manner and affords the corresponding water-soluble tetrahydroxymethyldivinyl selenides 6a,b in high yields.…”

mentioning

confidence: 99%

“…Recently, we have found that in situ prepared selenium dichloride, readily obtained from elemental selenium and sulfuryl chloride, 14 undergoes smooth 1,2-addition to the triple bond of various propargylic alcohols resulting in the formation of symmetrical (Z,Z)-bis(1-hydroxymethyl-2-chlorovinyl) selenides 1 in high yields and in completely regio-and stereospecific manner (Scheme 1). 15,16 Of special mechanistic interest is the observed syn-addition and anti-Markovnikov orientation.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Water-Soluble Vinyl Selenides and Their High Glutathione Peroxidase (GPx)-Like Antioxidant Activity

et al. 2013

Self Cite

View full text Add to dashboard Cite

A convenient procedure for the synthesis of novel bis-(1-hydroxymethyl-2-halo-3-hydroxy-1-propylene) selenides has been developed. On oxidation these compounds form novel seleno-spiro compounds and their glutathione peroxidase mimetic activity has been studied. They promote the hydrogen peroxide oxidation of phenylmethanethiol to the corresponding disulfide via a catalytic cycle.Key words: alkynes, selenium, oxidation, spiro compounds, diols Glutathione peroxidase (GPx) is a selenoenzyme that protects cells by catalyzing the reduction of peroxides with the stoichiometric reductant glutathione. 1The enzyme catalytic site includes a selenocysteine residue in which the selenium undergoes a redox cycle involving the selenolate anion as the active form, which reduces hydroperoxides. The selenol is first oxidized to a selenenic acid EnzSeOH, which reacts with reduced glutathione GSH to form the selenyl sulfide EnzSeSG. A second glutathione then regenerates the active form of the enzyme by attacking the EnzSeSG to form the oxidized glutathione GSSG. The overall catalytic cycle is depicted in Figure 1. Ebselen [2-phenyl-1,2-benzoisoselenazol-3(2H)-one] has been known as a mimetic of glutathione peroxidase (GPx), able to interact with active oxygen species present in living cells. [3][4][5][6] However, its use under nonenzymic conditions as a catalyst for hydrogen peroxide oxidation of thiols to disulfides gave poor results. Recently, Back et al. 7,8 have demonstrated the exceptional glutathione peroxidase-like activity of the simple bis(3-hydroxypropyl) selenide and the unexpected role of its oxidation product, spirodioxaselenanone, as an intermediate in the catalytic redox cycle for GPx.In view of the known role of organoselenium compounds in biological systems, [9][10][11][12] in addition to their unique characteristics in organic synthesis, 13 the design and synthesis of novel organoselenium compounds with potential biological activity constitutes an ongoing challenge. Recently, we have found that in situ prepared selenium dichloride, readily obtained from elemental selenium and sulfuryl chloride, 14 undergoes smooth 1,2-addition to the triple bond of various propargylic alcohols resulting in the formation of symmetrical (Z,Z)-bis(1-hydroxymethyl-2-chlorovinyl) selenides 1 in high yields and in completely regio-and stereospecific manner (Scheme 1). 15,16Of special mechanistic interest is the observed syn-addition and anti-Markovnikov orientation.Scheme 1 Regio-and stereospecific synthesis of functionalized divinyl selenides Inspired by the above findings, we applied our regio-and stereospecific SeCl 2 addition protocol in the planned preparation of novel GPx-mimetics of spirodioxaselenurane type. 8Those divinyl selenides formed by syn-addition of SeCl 2 to the triple bond, which do not bear a vicinal hydrogen capable of cis elimination, gave stable selenoxides 2a,b and selenone 3 in good yield upon oxidation with tert-butyl hydroperoxide or with 2 equivalents of MCPBA, respectively (Scheme 2). The divinyl s...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Synthesis of Water-Soluble Vinyl Selenides and Their High Glutathione Peroxidase (GPx)-Like Antioxidant Activity

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…These were separated by column chromatography on silica gel (hexane: EtOAc 4:1 as eluent). The more polar product ( R f = 0.08, yield 42 %) was identified as selenide 1 ( n = 2) by comparison with the spectral data of a known sample …”

Section: Resultsmentioning

confidence: 99%

“…Surprisingly, we have found that all aspects of the reaction of SeCl 2 with propargyl alcohols, i.e. identity of reacting functionality, regiospecifity, and stereospecifity, differ from expectations based on known reactions of these alcohols with SCl 2 (Scheme ) . SeCl 2 , prepared in situ from elemental selenium and sulfuryl chloride, reacts with propargyl alcohols via 1,2‐addition to the triple bond rather than with the ‐OH group and affords functionalized divinyl selenides 1 in high yields and in a complete regio‐ and stereospecific manner.…”

Section: Introductionmentioning

confidence: 80%

“…In continuation, it was found, that when in situ prepared selenium dichloride was reacted with either propargyl or homopropargyl alcohols in the presence of acetone, 1,2‐addition to the triple bond was accompanied by selenylation at the α‐position of the ketone, leading to the formation of novel selenium‐containing spiroketals 2 and 3 , respectively (Scheme ) …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

One‐pot three‐component preparation of novel selenium‐containing spiroketals

Braverman

Cherkinsky

Kalendar

et al. 2012

J of Physical Organic Chem

Self Cite

View full text Add to dashboard Cite

The one-pot three-component preparation of novel selenium-containing spiroketals with potential biological activity is described. When in situ prepared selenium dichloride is reacted with either propargyl or homopropargyl alcohols in the presence of acetone, two competitive reactions take place, namely 1,2-addition to the triple bond with the formation of the corresponding functionalized divinyl selenides in a completely regio-and stereospecific manner and selenylation at the a-position of the ketone, leading to the novel selenium-containing spiroketals. An alternative approach to the synthesis of the selenium-containing spiroketals with substantial increase of the chemical yield involves the reaction of alkynyl acetals with SeCl 2 . The structure of (4E,11E)-4,11-bis(chloromethylene)-1,8-dioxa-5,12-diselenaspiro[6.6] tridecane was unambiguously confirmed by X-ray analysis. These novel selenium-containing spiroketals were tested for regulation of glucose uptake in L6 myotubes. * Figure 5. Stimulatory effect of 3 on rate of glucose uptake in L6 myotubes. Myotube cultures were washed and received fresh a-MEM supplemented with 2% (v/v) FCS, 22.5. The myotubes were incubated for the 5 h. Control myotubes were untreated, and DMSO-treated myotubes received the vehicle only. The cultures were then taken for the dGlc uptake assay. Mean AE SEM. Statistical significance (p < 0.05) was calculated among experimental groups using the two-tailed Student's t test, *p < 0.05, in comparison to the respective controls, n = 3 S. BRAVERMAN ET AL.wileyonlinelibrary.com/journal/poc

show abstract

Addition Reactions: Polar Addition

Kočovský¹

2012

Organic Reaction Mechanisms Series

View full text Add to dashboard Cite

Reaction of selenium and tellurium halides with propargyl alcohols. The regio‐ and stereoselectivity of addition to the triple bond

Cited by 26 publications

References 62 publications

Synthesis of Water-Soluble Vinyl Selenides and Their High Glutathione Peroxidase (GPx)-Like Antioxidant Activity

Synthesis of Water-Soluble Vinyl Selenides and Their High Glutathione Peroxidase (GPx)-Like Antioxidant Activity

One‐pot three‐component preparation of novel selenium‐containing spiroketals

Addition Reactions: Polar Addition

Contact Info

Product

Resources

About