- Chirality transfer through sulfur or selenium to chiral propellers
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The mechanism of chirality transfer from a chiral alkyl substituent to a trityl moiety through sulfur or selenium atoms is analysed and discussed on the basis of ECD measurements, DFT structure and ECD spectra calculations. It is shown that the presence o
- Skowronek, Pawel,cianowski, Jacek,Pacula, Agata J.,Gawroski, Jacek
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p. 69441 - 69444
(2015/09/01)
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- Synthesis of new monoterpene sulfonylimidazoles
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Sulfonylimidazoles of monoterpenes of menthane, pinane, and carane nature were synthesized in 83-98% yields.
- Demakova,Sudarikov,Rubtsova,Frolova,Kuchin
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scheme or table
p. 38 - 42
(2012/07/28)
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- Clarification of the stereochemical course of nucleophilic substitution of arylsulfonate-based nucleophile assisting leaving groups
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(Chemical Equation Presented) Secondary alcohols modified as tosylates, PEG-sulfonates, or quisylates undergo inversion of configuration at the reacting center when treated with lithium halide in acetone at reflux, where the PEG-sulfonates and quisylates are substantially more reactive. In sterically hindered cases, elimination is a competing process. In contrast, when treated with TiCl4, simple secondary sulfonates give chloride products with partial inversion of configuration. Any observed retention of configuration in a given alkyl sulfonate substrate under these conditions is likely due to neighboring group participation or diastereoselective attack on a carbocation (or ion pair) rather than an SNi mechanism.
- Braddock, D. Christopher,Pouwer, Rebecca H.,Burton, Jonathan W.,Broadwith, Phillip
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supporting information; experimental part
p. 6042 - 6049
(2009/12/24)
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- An efficient organocatalyzed interconversion of silyl ethers to tosylates using DBU and p-toluenesulfonyl fluoride
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A mild and efficient interconversion from silyl ethers to sulfonates esters is reported with good yields. This silyl-sulfonyl exchange proceeds readily in acetonitrile at room temperature in the presence of p-toluenesulfonyl fluoride and a catalytic amount of 1,8-diazabicyclo[5.4.0]undec-7ene (DBU). This method can be used with trimethysilyl (TMS), triethylsilyl (TES) and tert-butyldimethylsilyl (TBDMS) ethers. Georg Thieme Verlag Stuttgart.
- Gembus, Vincent,Marsais, Francis,Levacher, Vincent
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experimental part
p. 1463 - 1466
(2009/04/07)
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- Syntheses and reactions of new optically active terpene dialkyl diselenides
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The reaction of sodium diselenide with optically active alkyl tosylates or chlorides is found to be a useful method for the synthesis of optically active dialkyl diselenides. Optically active monoterpene diselenides derived from menthane, carane, pinane,
- Scianowski, Jacek,Rafinski, Zbigniew,Wojtczak, Andrzej
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p. 3216 - 3225
(2007/10/03)
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- An efficient and selective tosylation of alcohols with p-toluenesulfonic acid
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Silica chloride has been found to be an efficient catalyst for facile tosylation of alcohols directly with p-toluenesulfonic acid in methylene chloride under reflux. The process is associated with selective tosylation of secondary alcohols over primary al
- Das, Biswanath,Reddy, V. Saidi,Reddy, M. Ravinder
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p. 6717 - 6719
(2007/10/03)
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- Cobalt(II) catalyzed tosylation of alcohols with p-toluenesulfonic acid
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Cobalt(II) chloride hexahydrate (CoCl2·6H2O) has been found to catalyze the tosylation of both aliphatic and aromatic alcohols with p-toluenesulfonic acid (p-TsOH) in high yields in 1,2-dichloroethane under reflux (ca. 80°C). In the
- Velusamy, Subbarayan,Kumar, J. S. Kiran,Punniyamurthy
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p. 203 - 205
(2007/10/03)
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- ZrCl4 as an efficient catalyst for selective tosylation of alcohols with p-toluenesulfonic acid
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Tosylation of alcohols has directly been carried out with p-toluenesulfonic acid in methylene chloride under reflux using ZrCl4 as a catalyst. Primary alcohols were found to be tosylated chemoselectively over secondary alcohols.
- Das, Biswanath,Reddy, Vtukuri Saidi
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p. 1428 - 1429
(2007/10/03)
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- Syntheses of Chiral Menthyl and Neomenthyl Sulfides, Sulfoxides and Sulfones
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Attempts to synthesize stereospecifically menthanethiol (2) and menthyl thiocyanate (3) from suitable electrophilic neomenthyl substrates (4a-c) and a variety of sulfur nucleophiles failed or predominatly led to β-elimination products.Almost quantitative
- Blanco, Jose Manuel,Caamano, Olga,Fernandez, Franco,Nieto, Isabel
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p. 538 - 541
(2007/10/03)
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- Chiral organolanthanides designed for asymmetric catalysis. Synthesis, characterization, and configurational interconversions of chiral, C1-symmetric organolanthanide halides, amides, and hydrocarbyls
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This contribution describes the synthesis, structural systematics, absolute configurations, and structural interconversions of a series of C1-symmetric lanthanide chloro, hydrocarbyl, and amide complexes/precatalysts based on chiral chelating M
- Giardello, Michael A.,Conticello, Vincent P.,Brard, Laurent,Sabat, Michal,Rheingold, Arnold L.,Stern, Charlotte L.,Marks, Tobin J.
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p. 10212 - 10240
(2007/10/02)
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- O-Sulfinylation of alcohols with methanesulfonyl cyanide or p-toluenesulfonyl cyanide
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Reaction of p-toluenesulfonyl cyanide or methanesulfonyl cyanide with alcohols in the presence of 1,8-diazabicyclo[5.4.0]under-7-ene (DBU) or 1,4-diazabicyclo[2.2.2]octane (DABCO) gives sulfinates in good yield. A mechanistic scheme involving sulfinyl cyanates 9 and 21 is suggested.
- Barton, Derek H. R.,Jaszberenyi, Joseph Cs.,Theodorakis, Emmanouil A.
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p. 9167 - 9178
(2007/10/02)
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- A SIMPLE METHOD FOR TOSYLATION WITH INVERSION
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In this paper we describe a simple one-step procedure for tosylation with inversion, using zinc tosylate, diethylazodicarboxylate and triphenylphospine.
- Galynker, Igor,Still, W. Clark
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p. 4461 - 4464
(2007/10/02)
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