33877-15-5

Upstream product

• 141561-41-3 <(SR)-2-Chloro-2-phenylethyl>-2,3:5,6-di-O-isopropyliden-β-D-mannofuran 
• 20780-53-4 (R)-Styrene oxide 
• 96-09-3 styrene oxide 
• 13461-16-0 1,3-dimethylimidazolidine-2-thione 

Downstream Products

• 4410-99-5 2-mercaptophenylethane 
• 33877-11-1 1-Phenylethanethiol 

Relevant academic research and scientific papers

Catalytic Enantioselective Conversion of Epoxides to Thiiranes

A highly efficient and enantioselective Br?nsted acid catalyzed conversion of epoxides to thiiranes has been developed. The reaction proceeds in a kinetic resolution, furnishing both epoxide and thiirane in high yields and enantiomeric purity. Heterodimer formation between the catalyst and sulfur donor affords an effective way to prevent catalyst decomposition and enables catalyst loadings as low as 0.01 mol %.

Reaction of optically active oxiranes with thiofenchone and 1-methylpyrrolidine-2-thione: Formation of 1,3-oxathiolanes and thiiranes

The SnCl4-catalyzed reaction of (-)-thiofenchone (=1,3,3-trimethylbicyclo[2.2.1]heptane-2-thione; 10) with (R)-2-phenyloxirane ((R)-11) in anhydrous CH2Cl2 at -60° led to two spirocyclic, stereoisomeric 4-phenyl-1,3-oxathiolanes 12 and 13 via a regioselective ring enlargement, in accordance with previously reported reactions of oxiranes with thioketones (Scheme 3). The structure and configuration of the major isomer 12 were determined by X-ray crystallography. On the other hand, the reaction of 1-methylpyrrolidine-2-thione (14a) with (R)-11 yielded stereoselectively (S)-2-phenylthiirane ((S)-15) in 56% yield and 87-93% ee, together with 1-methylpyrrolidin-2-one (14b). This transformation occurs via an SN2-type attack of the S-atom at C(2) of the aryl-substituted oxirane and, therefore, with inversion of the configuration (Scheme 4). The analogous reaction of 14a with (R)-2-{[(triphenylmethyl)oxy] methyl}oxirane ((R)-16b) led to the corresponding (R)-configured thiirane (R)-17b (Scheme 5); its structure and configuration were also determined by X-ray crystallography. A mechanism via initial ring opening by attack at C(3) of the alkyl-substituted oxirane, with retention of the configuration, and subsequent decomposition of the formed 1,3-oxathiolane with inversion of the configuration is proposed (Scheme 5). Copyright

Ring enlargement and sulfur-transfer processes in SiO2-catalyzed reactions of thiocarbonyl compounds with optically active oxiranes

The reactions of 1,3-dioxolane-2-thione (3) with (S)-2-methyloxirane ((S)-1) and with (R)-2-phenyloxirane ((R)-2) in the presence of SiO2 in anhydrous dichloroalkanes led to the optically active spirocyclic 1,3-oxathiolanes 8 with Me at C(7) and 9 with Ph at C(8), respectively (Schemes 2 and 3). The analogous reaction of 1,3-dimethylimidazolidine-2-thione (4a) with (R)-2 yielded stereoselectively (S)-2-phenylthiirane ((S)-10) in 83% yield and 97% ee together with 1,3-dimethylimidazolidin-2-one (11a). In the cases of 3-phenyloxazolidine-2-thione (4b) and 3-phenylthiazolidine-2-thione (4c), the reaction with (RS)-2 yielded the racemic thiirane (RS)-10, and the corresponding carbonyl compounds 11b and 11c (Scheme 4 and Table 1). The analogous reaction of 4a with 1,2-epoxycyclohexane (=7-oxabicyclo[4.1.0]heptane; 7) afforded thiirane 12 and the corresponding carbonyl compound 11a (Scheme 5). On the other hand, the BF3-catalyzed reaction of imidazolidine-2-thione (5) with (RS)-2 yielded the imidazolidine-2-thione derivative 13 almost quantitatively (Scheme 6). In a refluxing xylene solution, 1,3-diacetylimidazolidine-2-thione (6) and (RS)-2 reacted to give two imidazolidine-2-thione derivatives, 13 and 14 (Scheme 7). The structures of 13 and 14 were established by X-ray crystallography (Fig.).

A green protocol for the easy synthesis of thiiranes from epoxides using thiourea/silica gel in the absence of solvent

The use of thiourea/silica gel provides a green protocol for the easy and high-yielding preparation of thiiranes from different classes of epoxides in the absence of solvent at room temperature. The high stereospecific conversion of (R)(+)-styrene oxide to (S)(+)-styrene sulfide is also reported using this reagent system. Copyright Taylor & Francis Inc.

Conversion of epoxides to thiiranes with thiourea or ammonium thiocyanate catalyzed with poly(4-vinyl pyridine)-Ce(OTf)4

Conversion of epoxides to thiiranes with ammonium thiocyanate or thiourea in the presence of poly(4-vinyl pyridine)-Ce(OTf)4 as catalyst and under non-aqueous condition is reported. Stereospecific conversion of R-(+)- styrene oxide to S-(-)-styrene sulfide was achieved in high optical purity. The polymer can be easily reloaded.

Stereospecific formation of S(-) styrene sulfide: Efficient conversion of epoxides to thiiranes catalysed with Ru(III)

Ru(III) catalysis the efficient conversion of different epoxides to their corresponding thiiranes in the presence of ammonium thiocyanate in excellent yields, Stereospecific conversion of R(+) styrene oxide to S(-) styrene sulfide was achieved in high optical purity.

Glycosylsulfenyl and (Glycosylthio)sulfenyl Halides (Halogeno and Halogenothio 1-Thioglycosides, Resp.): Preparation and Reaction with Alkenes

The disulfides 11-17 and 20 were prepared from 7, 9, and 18 via the dithiocarbonates 8, 10, and 19, respectively (Scheme 2).The structure of 11 and of 13 was established by X-ray analysis.Chlorolysis (SO2Cl2) of 11 gave mostly the sulfenyl chloride 24, characterized as the sulfenamide 26, a small amount of 21, characterized as the (glycosylthio)sulfenamide 23, and the glycosyl chloride 27 (Scheme 3).Bromolysis of 11 followed by treatment of the crude with PhNH2 yielded only 28.Chlorolysis of the diglycosyl disulfide 13, however, gave mostly the (glycosylthio)sulfenyl chloride 21 and 27, besides 24.Bromolysis of 13 (-> 22 and traces of 25) followed by treatment with PhNH2 gave an even higher proportion of 23.Similarly, 20 led to 29 and hence to 30.In solution (CH2Cl2) the sulfenyl chloride 24 decomposes faster than the (thio)sulfenyl chloride 21, and both interconvert.Addition of crude 24 to styrene (-78 deg C) yielded the chloro-sulfide 31 and some 37, both in low yields.The product of the addition of 24 to 1-methylcyclohexene was transformed into the triol 32.Silyl ethers of allylic alcohols reacted with 24 only at room temperature, yielding, after desilylation, isomer mixtures 33 and 34, and pure 35.Much higher yields were achieved for the addition of (thio)sulfenyl halides yielding halogeno-disulfides.Good diastereoselectivities were only obtained with 21, its cyclohexylidene-protected analogue, and 22, and this only in the addition to styrene (-> 36, 37, 38), to (E)-disubstituted alkenes (-> 46, 48, 49a,b, 50a,b, 53), and to trisubstituted alkenes (-> 47, 51, 52, 54, 55).Other monosubstituted alkenes (-> 41-45) and (Z)-hex-2-ene (-> 49c,d, 50c,d) reacted with low diastereoselectivities.Where structurally possible, a stereospecific trans-addition was observed: regioselectivity was observed in the addition to mono- and trisubstituted alkenes and to derivatives of allyl alcohols.The absolute configuration of the 2-chloro-disulfides was either established by X-ray analysis (47a) or determined by transforming (LiAlH4) the chloro-disulfides into known thiiranes (Scheme 5).Thus, 37, 48, and the mixtures of 49a/b and 50a/b gave the thiiranes 56, 61, and 64, respectively, in good-to-acceptable yields (Scheme 5).Harsher conditions transformed 56 into the thiols 57 and 58.Similarly, 61 gave 62.The enantiomeric excesses of these thiols were determined by GC analysis of their esters obtained with (-)-camphanoyl chloride.Addition of 21 to trimethylsilane, followed by LiAlH4 reduction and desilylation, gave the known 66 (63percent, e.e. 74percent).The diastereoselectivity of the addition of 21 to trans-disubstituted and trisubstituted alkenes is rationalized by assuming a preferred conformation of the (thio)sulfenyl chloride and destabilizing steric interactions with one of the alkene substituents, . . .