34804-74-5Relevant academic research and scientific papers
Diselenide-assisted sulfuration of dienes
Rys, Andrzej Z.,Hou, Yihua,Abu-Yousef, Imad A.,Harpp, David N.
, p. 9181 - 9184 (2007/10/03)
Various diselenides assist in the sulfuration of dienes giving cyclic di- and tetrasulfides as main products. The reaction requires a 2-fold excess of diselenides to be efficient. Catalytic amounts of diselenides result in lower yields. This is likely due to secondary reactions (polymerization, aromatization) occurring during extended reaction times under catalytic conditions. It was verified that the sulfur-transferring properties of diselenatetrasulfides are virtually identical to those of diselenides combined with sulfur. Contrary to previous claims, not only the cyclic diselenatetrasulfide but also linear diselenatetrasulfides (RSeSnSeR) transfer sulfur to dienes. A mechanism is proposed and its implications to the nature of diatomic sulfur are discussed.
Dialkoxy disulfides from cubycarbinols
Priefer, Ronny,Farrell, Patrick G,Harpp, David N
, p. 8781 - 8784 (2007/10/03)
Two dialkoxy disulfides 2 and 3 have been synthesized in respectable yields. The behaviour of 2 and 3 under thermal and photolytic conditions has been examined and we report the first examples of S2 liberation from aliphatic dialkoxy disulfides.
Insertion of a two sulfur unit into the S-S bond - Tailor-made polysulfides
Rys,Harpp
, p. 7169 - 7172 (2007/10/03)
Triphenylthiosulfenyl chloride (1) reacts with disulfides RSSR, yielding tetrasulfides as the main products. The results of the insertion for different R groups are reported. A two-step mechanism involving the formation of unsymmetrical trisulfide intermediates containing the trityl group is proposed. (C) 2000 Elsevier Science Ltd.
Sulfur allotrope chemistry - S10 an effective two-sulfur transfer reagent
Leste-Lasserre, Pierre,Harpp, David N.
, p. 7961 - 7964 (2007/10/03)
The chemistry of one of the sulfur allotropes has been investigated. Cyclodecasulfur (S10) reacts with conjugated 1,3-dienes and strained olefins to deliver cyclic di- and polysulfides with a better selectivity and under milder conditions than with elemental sulfur (S8). A radical mechanism is proposed for these sulfuration reactions.
Catalytic sulfuration of dienes with metallocene polysulfides
Rys, Andrzej Z.,Harpp, David N.
, p. 9139 - 9142 (2007/10/03)
Elemental sulfur reacts with conjugated 1,3-dienes to give cyclic di- and tetrasulfides. The yield is significantly improved in the presence of catalytic amounts of organometallic polysulfides. The nature of this effect is discussed.
The sulfur diatomics: Generation and trapping chemistry
Harpp, David N.
, p. 41 - 59 (2007/10/03)
Aspects of the generation and trapping of diatomic sulfur (S2) and sulfur monoxide (SO) are reviewed with special emphasis on recent work.
Sulfuration of dienes with elemental sulfur
Rys, Andrzej Z.,Harpp, David N.
, p. 4931 - 4934 (2007/10/03)
Elemental sulfur reacts with conjugated 1,3-dienes to deliver cyclic di- and polysulfides; the reaction proceeds without any activation other than heat. Treatment of cyclic polysulfide products with triphenylphosphine cleanly converts them to the corresponding disulfide in good overall yield. Additionally, some mechanistic aspects have been examined. The presence of disulfur as an active species in the sulfuration of dienes with S8 is discussed.
Recent chemistry of the chalcogen diatomics
Tardif, Sylvie L.,Rys, Andrzej Z.,Abrams, Charles B.,Abu-Yousef, Imad A.,Leste-Lasserre, Pierre B. F.,Schultz, Erwin K. V.,Harpp, David N.
, p. 12225 - 12236 (2007/10/03)
The chemistry of the generation and trapping of diatomic sulfur (S2) and sulfur monoxide (SO) are reviewed with special emphasis on recent work, including initial efforts to detect and trap diatomic selenium (Se2).
Dithiatopazine1 and related systems. Synthesis, chemistry, X-ray crystallographic analysis and calculations
Nicolaou,DeFrees,Hwang,Stylianides,Carroll,Snyder
, p. 3029 - 3039 (2007/10/02)
The synthesis and chemistry of dithiatopazine (11), a stable 1,2-dithietane system, are described. Theoretical studies with this novel system are also included. The synthesis of 11 was achieved via controlled photoirradiation of dithionolactone 10. Photolytic or thermal decomposition of 11 led to olefin 12, a conversion that could also be carried out by a variety of reagents. Triphenylphosphine treatment of 11 led to the loss of one sulfur and the formation of the rearranged products 18 and 19. Treatment of 11 with PhS- resulted in the formation of 25, whereas brief exposure to NaBH4 followed by trapping with MeI led to the novel episulfides 31a and 31b. Exposure of 11 to AgBF4-Et3SiH resulted in a novel skeletal rearrangement leading to compound 36. Dithiatopazine (11), served as a sulfur-transfer reagent converting, under thermal conditions, diene 41 to cyclic sulfides 42 and 43 and acetylene 44 to the novel systems 45 and 46. Kinetic studies on the thermal decomposition of 11 revealed an activation energy for this process of 26.3 kcal/mol. Several X-ray crystallographic analyses, including that on dithiatopazine (11) are included in this study. MM2 parameterization for dithietanes and subsequent molecular mechanics evaluation permits the conclusion that dithiatopazine is a remarkably rigid structure experiencing little conformational mobility. Quantum mechanical (PRDDO) calculations for various dithietane systems suggest the singular stability of dithiatopazine to arise from a combination of thermodynamic factors and internal energy redistribution. Finally, MM2 parameters for episulfides were derived to allow for a comparison between dithiatopazine and its episulfides and bis(methylthio) analogues.
