Reaction with dibutyl sulfide

CASRN 544-40-1 molecular formula CsHisS FW 146.29 ChemicaPPhysical. MacLeod et al. (1984) studied the reaction of hydroxyl radicals ( limiting reagent ) with dibutyl sulfide in a discharge flow reactor. The rate constants for this reaction at 20,... 

Reaction of various aldehydes with hydrogen sulfide leads to substituted thiophenes, dihydrothiophenes, dithiolanes and trithiolane, as well as to six-membered ring thiopyran derivatives and dithiins. Ledl (33) obtained 2,4-dimethylthiophene (1, R Me) as a product of the reaction of propionaldehyde with hydrogen sulfide in the presence of ammonia. Sultan (29) reported the formation of 2,4-diethylthiophene (1, R - Et), 2,4-dibutyl-thiophene (1, R - Bu), and their dehydro derivatives from the reaction of ammonium sulfide with butyraldehyde and caproaldehyde (hexanal), respectively. The mechanism suggested for their formation is depicted in Scheme 1. Space limitations do not allow us to discuss the mechanism here in detail (for additional information, see ref. 29). 

Dibutyl sulfide is converted into dibutyl sulfoxide with one equivalent of peroxytrifluoroacetic add and into dibutyl sulfone with two equivalents of peroxytrifluoroacetic acid [279]. On the other hand, with manganese dioxide, dibutyl sulfide yields dibutyl sulfoxide exclusively 541], and with chromic acid, it yields dibutyl sulfoxide, even when an excess of the oxidant is used and even when the reaction is carried out at 100 °C 541] (equation 552). 

In the presence of visible light irradiation provided by a 120 W lamp and with 1 atm of O2, the Ru(II) complex in solution promoted the oxidation of dibutyl sulfide to the corresponding dibutyl sulfoxide obtained in 32% yield. Under identical experimental conditions but in the presence of the capsule, the reaction did not occur as a consequence of the encapsulation of the Ru(ll) photocatalyst. The catalytic activity was restored when repeating the same experiment with [Ru(bpy)3] in the presence of both capsule and tetraethylam-monium competitive guest, due to the displacement of the metal catalyst from the cavity of the capsule. Similar results were observed with other thioethers showing conversions to the corresponding sulfoxides that were dependent on the electron density on the sulfur atom in all cases, no conversion was observed with the encapsulated Ru(ll) catalyst. Since it was danonstrated that the absorption properties of the Ru(ll) metal center were substantially not influenced by the capsule, it is likely that the inactivation provided by the capsule could be due to interrupted energy transfer from the Ru(ll) center to O2. 

As for the end-linking, an experimental work has already been published for the viscoelastic relaxation of poly(propylene sulfide) star by Nicol et al., they discussed the relation of p and viscoelasticity in detail. (Nicol et al, 2001) It is a 3-arm star polymer and can be end-linked by the reaction with hexamethyl diisocyanate(HMDI) in the presence of a small amount of catalyst of dibutyl tin dilaurate. Also, it is regarded as a network formation of RA3 + R B2 type reaction.(The values are functionalities.) The characteristic features to remark for poly(propylene sulfide) star, abbreviated as PPS star, is low Tg( -37°C). 

Reactions of sulfoxides containing a- and /9-hydrogen atoms, for example n-dibutyl sulfoxide 1170, with trimethylsilyl iodide 17 in the presence of tertiary amines such as diisopropylethylamine (DIPEA) give, e.g., the vinylsulfide 1171 as an 1 1 E/Z mixture in 75% yield and HMDSO 7 [16] (Scheme 8.4). Analogously, the vinyl sulfoxide 1172 or the vinyl sulfoxide 1174 furnish the 1,3-dienyl sulfides 1173 and 1175 in 91 and 85% yield, respectively, and HMDSO 7 [16]. 

The synthesis of 2,3-dihydrodiisopropyl-l,3-thiaborol-3-yl-amine 26 and subsequently lithium diisopropyl-1,3-thiaborol-3-ylamine 27 required a four-step synthesis starting from chloromethyl trimethylsilylethynyl sulfide 59 (Scheme 9). Desilylation of compound 59 with tetrabutylammonium fluoride (TBAF) in methanol afforded the labile chloromethyl ethynyl sulfide 60, which was treated with a solution of dibutylstannane and LDA in a mixture of TFIF and hexane at —78°C to give 3,3-dibutyl-2,3-dihydro-l,3-thiastannole 61, in 39% yield. Reaction of compound 61 with 2 equiv of -butyllithium in THF at —78°C gave the dilithio reagent 62, which could be detected by NMR... 

Sulfur-Containing Substrates. HOF-MeCN is able to transfer its oxygen atom to sulfides and form sulfones at room temperature, usually in nearly quantitative yields with reaction times of seconds or minutes. Unhindered (such as dibutyl-) or very hindered (di-tert-butyl-) sulfides behave alike and produce the corresponding sulfones. Sulfones are easily also obtained from sulfoxides. When a low temperature (—78 °C) is maintained, and methanol is added, the oxidation of sulfides could be stopped at the sulfoxide stage as demonstrated for dibenzylsulfide, but in general the reaction favors the formation of sulfones (eqs 19 and 20). 

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