Selenium Dichloride Research Articles

BIS-E-Chloromethylidene Derivatives of 4-Thio- and 4-Selenomorpholinamines

It is known that the reaction of bis(2-haloethyl) sulfides with substituted amines gives 4-thiomorpholine and its N-substituted derivatives [1], while the reaction with hydrazine hydrate yields 4-thiomorpholinamine [1, 2]. 4-Selenomorpholinamine is unknown, but 4-selenomorpholine and a series of its N-substituted derivatives have been reported [3, 4]. We have developed a general method for the preparation of the previously unknown bis-E-chloromethylidene derivatives of 4-thiomorpholinamine 3 and 4-selenomorpholinamine 4. The method is composed of two stages, the first of which is a stereoand regioselective reaction of sulfur or selenium dichloride with propargyl bromide, occuring as an anti-Markovnikov addition to give the E,E-bis(3-bromo-1-chloro-1-propen2-yl) sulfide (1) or selenide (2) in high yields [5, 6]. The second stage is a chemoselective nucleophilic substitution of the bromine atoms in the bromomethylene fragments of sulfide 1 and selenide 2 with hydrazine hydrate in the presence of NaOH to give the heterocycles 3 and 4 in high yields. This second stage includes the alkylation of one hydrazine amino group with two bromomethyl groups of the divinylchalcogenides 1 and 2, giving the unsymmetrical 1,1-disubstituted hydrazine derivatives, which is a typical feature of the reaction between hydrazine and alkyl halides [7].

ChemInform Abstract: Synthesis of 2,6‐Bis(chloromethyl)‐1,4‐diselenane.

AbstractThe reaction of diallyl selenide with selenium dichloride is chemo‐, regio‐, and stereoselective and affords the hitherto unknown diselenane (II) in good yield.

Selenium and sulfur dichlorides as chlorinating agents in the reaction with alkyl 2,2-dichlorovinyl sulfides

The chlorination of dichlorovinyl sulfides (I) is performed by using selenium or sulfur dichloride in the presence of FeCl3 or AlCl3 as catalyst.

ChemInform Abstract: Reaction of Selenium Dichloride with Methacrylic Acid.

AbstractA highly chemo‐, regio‐, and stereoselective reaction of selenium dichloride with methacrylic acid leads to the unexpected formation of previously unknown diselenide (II).

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

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 α‐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 SeCl2. 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. Copyright © 2012 John Wiley & Sons, Ltd.

ChemInform Abstract: Annulation of Phenyl Propargyl Ether with Selenium Dichloride.

AbstractThe selective preparation of the hitherto unknown dihydrobenzoxaselenine (II) is achieved.

Reaction of selenium dichloride with methacrylic acid

Selenium dichloride and dibromide in solution undergo disproportionation, so that they could not be isolated as individual substances [1]. Freshly prepared (in situ) selenium dichloride and dibromide are effective electrophilic reagents which are immediately involved in various transformations leading to organoselenium compounds [2–6]. We perform systematic studies on reactions of selenium dichloride and dibromide with compounds containing a double bond [3–5]. Reactions of selenium dihalides with divinyl sulfide [3] and divinyl selenide [4] give the corresponding Markovnikov addition products, 2,6-dihalo-1,4-thiaselenanes and -diselenanes, which undergo rearrangement into thermodynamically more stable 1,3-thiaselenolanes and -diselenolanes. Unlike vinyl sulfides and vinyl selenides, the double bond in vinyl sulfones is deactivated toward addition of electrophiles due to strong electron-withdrawing effect of the sulfonyl group. Selenium dihalides react with divinyl sulfone at a much lower rate as compared to divinyl sulfide, leading to fourand fivemembered heterocycles [6]. Methacrylic acid is a compound whose molecule contains a double bond and a strong electron-withdrawing group. Reactions of selenium halides with methacrylic acid were not studied. We examined the reaction of selenium dichloride with methacrylic acid at a molar ratio of 1 : 2 in acetonitrile at room temperature. Instead of expected 1 : 2 adduct we isolated in high yield (92%) a compound containing a diselenide moiety, previously unknown 2,2′-diselanediylbis(3-chloro-2-methylpropanoic acid) (I), whereas no analogous monoselenide was detected. Diselenide I was also obtained when Se2Cl2 was used instead of SeCl2; in this case, the reaction was accompanied by liberation of an equimolar amount of elemental selenium. The structure of diselenide I was confirmed by the H, C, and Se NMR and mass spectra and elemental analysis. It was isolated as two diastereoisomers at a ratio of 8 : 1. The observed coupling constant between the selenium atom and quaternary carbon atom (JSeC = 77 Hz for the major diastereoisomer) corresponds to direct coupling (JCSe) [7]. Thus the reaction of selenium dichloride with methacrylic acid is chemo-, regio-, and stereoselective, and it leads to the formation of diselenide I. Probable mechanism of this transformation is now under study. 2,2′-Diselanediylbis(3-chloro-2-methylpropanoic acid) (I). White powder, mp 121–122°C. H NMR spectrum, δ, ppm: major diastereoisomer: 1.52 s (6H, CH3), 3.85 d and 4.14 d (2H each, CH2Cl, J = 10.6 Hz); minor diastereoisomer: 1.53 s (6H, CH3), 3.81 d and 4.11 d (2H each, CH2Cl, J = 10.6 Hz). C NMR spectrum, δC, ppm: major diastereoisomer: 20.74 (CH3, JSeC = 16.2 Hz), 49.11 (CCH3, JCSe = 77 Hz), 51.29 (CH2Cl, JSeC = 15.1 Hz), 172.21 (C=O); minor diastereoisomer: 20.65 (CH3), 49.21 (CCH3), 51.29 (CH2Cl), 172.05 (C=O). Se NMR spectrum: major diastereoisomer: δSe 545 ppm; minor diastereoisomer: δSe 544 ppm. Mass spectrum (electron impact, 70 eV), m/z (Irel, %): 402 (4) [M] , 236 (10), 200 (7), ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 12, pp. 1889–1890. © Pleiades Publishing, Ltd., 2011. Original Russian Text © V.A. Potapov, S.V. Amosova, A.G. Khabibulina, L.I. Larina, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 12, pp. 1853–1854.

ChemInform Abstract: Reactions of Selenium Dichloride and Dibromide with Unsaturated Ethers. Annulation of 2,3‐Dihydro‐1,4‐oxaselenine to the Benzene Ring.

AbstractDepending on the conditions, reactions of phenylethers (I) and (III) with selenium dihalides can be directed selectively either to annulation or to formation of bis‐adducts.

ChemInform Abstract: Reaction of Selenium Dichloride with Allyl Phenyl Ether.

AbstractThe regio‐ and stereoselective reaction of selenium dichloride with allyl phenyl ether (I) yields a new heterocyclic compound, dihydrobenzoxaselenine (II).

Synthesis of 2,6-bis(chloromethyl)-1,4-diselenane

The reaction of diallyl selenide with selenium dichloride is chemo-, regio-, and stereoselective and affords the hitherto unknown diselenane (II) in good yield.

Reactions of selenium dichloride and dibromide with diallyl telluride

Reactions of selenium dichloride and dibromide with diallyl telluride

Reactions of selenium dichloride and dibromide with unsaturated ethers. Annulation of 2,3-dihydro-1,4-oxaselenine to the benzene ring

Highly chemo-, regio-, and stereoselective syntheses of novel organoselenium compounds from selenium dichloride or dibromide and unsaturated ethers are described. The reactions of selenium dichloride with allyl and propargyl phenyl ethers afford either annulated products or bis-adducts depending on the conditions. The first examples of annulation of 3-chloromethyl- and 3-chloromethylene-2,3-dihydro-1,4-oxaselenine to the benzene ring are reported.

Reaction of selenium dichloride with allyl phenyl ether

The regio- and stereoselective reaction of selenium dichloride with allyl phenyl ether (I) yields a new heterocyclic compound, dihydrobenzoxaselenine (II).

Reaction of selenium dichloride with divinyl telluride

Reaction of selenium dichloride with divinyl telluride

Annulation of phenyl propargyl ether with selenium dichloride

We are performing systematic studies aimed at the ap plication of novel reagents, such as selenium dichloride and dibromide, in the chemistry of organoselenium com pounds.1—6 Although these reagents cannot be isolated in pure state and undergo disproportionation in solutions7, it has been shown1 that freshly prepared selenium dichloride and dibromide can be used as selective electrophilic re agents in the synthesis of organoselenium compounds. The reactions of selenium dichloride and dibromide with acet ylene,2 diphenylacetylene,3 divinyl sulfide,4 divinyl sul fone,5 divinyl selenide,6 propargyl alcohols,8 2,3 di methoxybuta 1,3 diene9 have been studied. In contrast to selenium tetrahalides, whose reactions with organic sub stances often afford mixtures of products10, the reactions of selenium dihalides proceed selectively to afford the tar get compounds in high yields.1—6,8,9 The use of selenium dihalides for annulation of phenyl ethers containing unsaturated groups by combination of the addition to the unsaturated bond and electrophilic sub stitution in the ortho position of the benzene ring is of the utmost interest. There are no data on annulation of phenyl propargyl ether with selenium halides. We studied the reaction of selenium dichloride with phenyl propargyl ether and found the conditions that al low selective preparation of previously unknown E 3 chloromethylidene 2,3 dihydro 1,4 benzoxaselenine (1). The highest yield of product 1 (80%) was obtained upon mixing reagents at low temperature (–60 °C) in chloro form followed by heating the reaction mixture to the boil ing temperature of the solvent. One can assume that the addition of selenium dichlo ride to the propargyl group occurs at low temperature and the second step, viz., electrophilic aromatic substitution, requires heating of the reaction mixture. The structure of product 1 was established by 1H, 13C (including JMOD), and 77Se NMR spectroscopy and con firmed by the data from mass spectrometry and elemental analysis. The value of spin spin coupling constant (100 Hz) between the selenium atom and the double bond carbon atom having no protons corresponds to the C—Se direct constant (JC—Se), which is evidence of the addition of the selenium atom to the central carbon atom of the propargyl group. The E configuration of product 1 was established using the NOESY spectra. The regio and stereospecificity of the process can be explained by the fact that the reaction proceeds via the intermediate selenirenium ion А, which is attacked by the chloride ion at the sterically unshielded terminal car bon atom. Thus, we showed for the first time the possibility of annulation of the selenium containing heterocycles to the benzene ring based on the reaction of selenium dichloride with unsaturated organyl phenyl ethers, where the addi tion of selenium halides to the unsaturated bond of orga nyl phenyl ethers and electrophilic aromatic substitution is combined.

Synthesis and Reactivity of Divinylselenium Dichlorides and Dibromides

Regio- and stereospecific electrophilic addition reactions of selenium tetrachloride and selenium tetrabromide to propargyl alcohols are reported. (Z,Z)-Bis(β-chlorovinyl)selenium dichlorides were isolated in high yields, and their reactivity was dependent on their substitution pattern. Products derived from unsubstituted, α-methyl-, or α,α-dimethylpropargyl alcohols readily underwent transfer of chlorine atoms to one of the two double bonds. (Z,Z)-Bis(β-chlorovinyl)selenium dichlorides derived from γ-phenyl- or γ-isopropenylpropargyl alcohols underwent cyclization to form benzoselenophene derivatives; this was accompanied by the formation of the corresponding dichloro-substituted allylic alcohols. In contrast, selenium tetrachloride reacts with γ-phenylpropargyl alcohol exclusively as a chlorinating agent, giving (3-chloroprop-1-yn-1-yl)benzene quantitatively. Products of regio- and stereospecific electrophilic addition of selenium tetrabromide are also described. Reaction mechanisms are proposed.

ChemInform Abstract: Synthesis of a New Four‐Membered Heterocycle by Reaction of Selenium Dichloride with Divinyl Sulfone.

Selenium dichloride and dibromide were not isolated as individual substances. It is known that selenium dichloride in solution exists in equilibrium with selenium tetrachloride and Se2Cl2, whereas the equilibrium of selenium dibromide in solution involves Se2Br2 and bromine [1, 2]. We were the first to reveal that freshly prepared selenium dichloride and selenium dibromide can be used in selective synthesis of organic selenides [3, 4]. Reactions of selenium dichloride and dibromide with divinyl chalcogenides and their derivatives opened a synthetic route to new heterocyclic compounds [5–10]. In continuation of our systematic studies on the chemical properties of selenium dihalides [3–10], we examined previously unknown addition of selenium dichloride to divinyl sulfone. It was found that the reaction occurs with high regioselectivity and leads to the formation of a new four-membered heterocyclic compound, 2,4-bis(chloromethyl)-1,3-thiaselenetane 1,1-dioxide (I). The yield of compound I was 85%, calculated on the reacted divinyl sulfone, the conversion of the latter being 58%. sional correlation techniques, as well as by mass spectrometry and elemental analysis. According to the NMR data, compound I was isolated as a mixture of two diastereoisomers at a ratio of 2.5 : 1. 2,4-Bis(chloromethyl)-1,3-thiaselenetane 1,1-dioxide (I). mp 76–77°C. Major diastereoisomer: H NMR spectrum, δ, ppm: 3.91 d.d (2H, CH2Cl, J = 11.8, J = 7.1 Hz), 4.27 d.d (2H, CH2Cl, J = 11.8, J = 7.1 Hz), 5.52 d.d (2H, CHSe, J = 7.1, 7.1 Hz). C NMR spectrum, δC, ppm: 41.39 (CH2Cl), 69.36 (CHSe). Se NMR spectrum: δSe 193 ppm. Minor diastereoisomer: H NMR spectrum, δ, ppm: 3.93 d.d (2H, CH2Cl, J = 11.9, J = 7.7 Hz), 4.31 d.d (2H, CH2Cl, J = 11.9, J = 7.9 Hz), 5.54 d.d (2H, CHSe, J = 7.7, 7.9 Hz). C NMR spectrum, δC, ppm: 41.63 (CH2Cl) , 70.03 (CHSe) . Se NMR spectrum: δSe 200 ppm. Mass spectrum, m/z (Irel, %): 268 (29) [M], 204 (12), 169 (100), 142 (56), 133 (34), 107 (82), 93 (24), 81 (13), 61 (19), 53 (21). Found, %: C 17.69; H 2.21; Cl 26.30. C4H6O2Cl2SSe. Calculated, %: C 17.93; H 2.26; Cl 26.46. The NMR spectra were recorded from solutions in CDCl3 on a Bruker DPX-400 instrument at 400.13 (H, HMDS), 100.61 (C, HMDS), and 76.30 MHz (Se, Me2Se). The mass spectrum (electron impact, 70 eV) was obtained on a Shimadzu GCMS-QP5050A instrument. This study was performed in the framework of the Basic Research Program of the Russian Academy of Sciences (project no. 5.1.8).

ChemInform Abstract: Reactions of Selenium Dichloride and Dibromide with Divinyl Sulfone: Synthesis of Novel Four‐ and Five‐Membered Selenium Heterocycles.

AbstractProducts (IV) and (VII) are formed during purification by silica gel chromatography via dehalogenation of the primary products (III) and (VI).

Regioselective reactions of sulfur, selenium and tellurium chlorides with allyl trimethyl silane

Electrophilic addition of SCl 2, SeCl 2 and SeCl 4 to 2 equivalents of allyl trimethyl silane proceeds regioselectively to give bis[2-chloro-3-(trimethylsilyl)propyl] sulfide, selenide and selenium dichloride, respectively. The reaction with TeCl 4 affords only diallyl tellurium dichloride. The structures of the compounds were confirmed by 1H, 13C, 77Se and 125Te NMR techniques.

Reactions of selenium dichloride and dibromide with divinyl sulfone: synthesis of novel four- and five-membered selenium heterocycles

The reactions of selenium dichloride and dibromide with divinyl sulfone leading to novel selenium heterocycles, 2,4-bis(halomethyl)-1,3-thiaselenetane-1,1-diones and 5-halo-2-halomethyl-1,3-thiaselenolane-1,1-diones, have been studied. Under the action of silica gel or pyridine, 5-halo-2-halomethyl-1,3-thiaselenolane-1,1-diones undergo facile regioselective dehydrohalogenation into 5-halo-2-methylene-1,3-thiaselenolane-1,1-diones.