- NITROXIDE CHEMISTRY XXI. REACTIONS OF BIS(BISTRIFLUOROMETHYLAMINO-OXY)-MERCURY(II) AND NN-BIS(TRIFLUOROMETHYL)NITROXIDE WITH THIOCARBONYL COMPOUNDS
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Thiobenzophenone, 9-thiocarbonylfluorene and carbonyl sulphide react with the mercurial, Hg2, to form HgS and the compounds Ph2C2, (C6H4)2C2 and 2CO respectively.The last compound is also formed as the major product on mixing the mercurial with carbon disulphide.With thiophosgene, reaction occurs to form HgCl2 and a mixture of the compounds (CF3)2NSCOCl and (CF3)2NSCOON(CF3)2, which are thought to arise by rearrangement of the intermediates (CF3)2NOC(S)Cl and 2CS.A similar rearrangement may also occur during the reactions of thiobenzoyl chloride and aryl chlorothionoformates with the mercurial but the product mixtures from these reactions are more complex and pure compounds have not been isolated.Reaction between thiophosgene dimer and the mercurial results in a simple chlorine exchange to afford the 1,3-dithietane 2cyclo2S>.The low temperature reaction of thiophosgene with (CF3)2NO gives a thermally unstable product believed to be (CF3)2NOCCl2S(O)ON(CF3)2, while the similar reaction with thiobenzophenone appears to give (CF3)2NOCPh2SON(CF3)2, which decomposes above 0 deg C.
- Booth, B. L.,Browne, R. F.,Haszeldine, R. N.,Varley, J. S.
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Read Online
- A synthesis of 5'-amino-3',5'-dideoxyuridine
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The synthesis of 3',5'-dideoxy-5'-aminouridine starting from uridine is described.
- Bender, David M.,Hennings, D. David,Williams, Robert M.
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Read Online
- BORON CONTAINING COMPOUNDS AND THEIR USES
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The present disclosure contemplates novel boron-containing compounds and their uses as active agents that exhibit pesticidal activity such as antimicrobial, insecticidal, arachnicidal, and/or anti parasitic activity. An agrochemical composition containing such a compound and its use in, animal health, agriculture, or horticulture is also contemplated. A method for promoting plant performance and/or controlling, reducing, preventing, ameliorating, or inhibiting microbes, insects, arachnids, and/or parasites on or in an animal, a plant, a plant part, plant propagation material, and/or harvested fruits or vegetables is also contemplated.
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Paragraph 0270; 0271; 0273; 0274
(2020/03/29)
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- Bare-minimum fluorous mixture synthesis of a stereoisomer library of 4,8,12-trimethylnonadecanols and predictions of NMR spectra of saturated oligoisoprenoid stereoisomers
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All four diastereomers of a typical saturated oligoisoprenoid, 4,8,12-trimethylnonadecanol, are made by an iterative three-step cycle with the aid of traceless thionocarbonate fluorous tags to encode configurations. The tags have a minimum number of total fluorine atoms, starting at zero and increasing in increments of one. With suitable acquisition and data processing, each diastereomer exhibits characteristic chemical shifts of methyl resonances in its 1H and 13C NMR spectra. Together, these shifts provide a basis to predict the appearance of the methyl region of the spectrum of every stereoisomer of higher saturated oligoisoprenoids.
- Yeh, Edmund A.-H.,Kumli, Eveline,Damodaran, Krishnan,Curran, Dennis P.
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supporting information
p. 1577 - 1584
(2013/03/28)
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- Cysteine as a sustainable sulfur reagent for the protecting-group-free synthesis of sulfur-containing amino acids: Biomimetic synthesis of l-ergothioneine in water
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Biomass-derived cysteine was used as a sustainable sulfur source for the synthesis of rare sulfur-containing amino acids, such as l-ergothioneine (4), which might be a new vitamin, and various l- or d-2-thiohistidine compounds. Key in this simple, one-pot two-step procedure in water is a bromine-induced regioselective introduction of cysteine followed by a novel thermal cleavage reaction in the presence of thiols, a safer alternative to hazardous red phosphorus. Besides avoiding hazardous sulfur reagents, the new protecting-group-free approach reduces drastically the total number of steps, compared to described procedures. The main drawback, i.e. handling of liquid bromine as an activating and oxidizing reagent in water, was addressed by evaluating four alternative methods using in situ generation of bromine or HOBr, and first encouraging results are described.
- Erdelmeier, Irene,Daunay, Sylvain,Lebel, Remi,Farescour, Laurence,Yadan, Jean-Claude
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supporting information; scheme or table
p. 2256 - 2265
(2012/09/08)
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- Radical OfC transposition: A metal-free process for conversion of phenols into benzoates and benzamides
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We report a metal-free procedure for transformation of phenols into esters and amides of benzoic acids via a new radical cascade. Diaryl thiocarbonates and thiocarbamates, available in a single high-yielding step from phenols, selectively add silyl radicals at the sulfur atom of the CdS moiety. This addition step, analogous to the first step of the Barton-McCombie reaction, produces a carbon radical which undergoes 1,2 OfC transposition through an O-neophyl rearrangement. The usually unfavorable equilibrium in the reversible rearrangement step is shifted forward via a highly exothermic C-S bond scission in the O-centered radical, which furnishes the final benzoic ester or benzamide product. The metal-free preparation of benzoic acid derivatives from phenols provides a potentially useful alternative to metal-catalyzed carbonylation of aryl triflates.
- Baroudi, Abdulkader,Alicea, Jeremiah,Flack, Phillip,Kirincich, Jason,Alabugin, Igor V.
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experimental part
p. 1521 - 1537
(2011/06/11)
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- DIRECT CONVERSION OF PHENOLS INTO AMIDES AND ESTERS OF BENZOIC ACID
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A method is provided for the preparation of an aromatic carboxylic acid aryl ester or an N-aryl aromatic carboxamide. The method comprises contacting an O,O-diaryl thiocarbonate or an O-aryl-N-aryl thiocarbamate with a reactant that regioselectively reacts with sulfur, which contact causes an O-neophyl rearrangement, thereby forming either the aromatic carboxylic acid aryl ester or the N-aryl aromatic carboxamide, respectively.
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Page/Page column 14-15; 16
(2011/10/12)
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- Radical 1,2-o→c transposition for conversion of phenols into benzoates by o-neophyl rearrangement/fragmentation cascade
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Figure Presented Radical merry-go-round! Diaryl thiocarbonates, available in a single step from phenols, can be directly transformed into benzoates by a new radical cascade that transposes O and C atoms at the aromatic core. The cascade bypasses the common Barton McCombie fragmentation in favor of the usually unfavorable O-neophyl rearrangement, which is rendered irreversible and efficient by a highly exothermic C-S bond scission in the O-centered radical (see scheme; FG = functional group).
- Baroudi, Abdulkader,Alicea, Jeremiah,Alabugin, Igor Y.
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supporting information; experimental part
p. 7683 - 7687
(2010/08/22)
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- Aminolysis of aryl chlorothionoformates with anilines in acetonitrile: Effects of amine nature and solvent on the mechanism
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The aminolysis of aryl chlorothionoformates (7, YC6H 4OC(=S)Cl) with anilines (XC6H4NH2) in acetonitrile at 5.0 °C has been investigated. The rates are slower than those for the corresponding reactions of aryl chloroformates (6, YC 6H4OC(=O)Cl). This rate sequence is a reverse of that for alkyl chloroformates (1 4) in water, for which rate-limiting formation of a tetrahedral intermediate, T±, is predicted. On the basis of the large negative cross-interaction constant, ρXY = -0.77, failure of the reactivity-selectivity principle, normal kH/k D values involving deuterated nucleophiles (XC6H 4ND2), and low ΔH≠ with large negative ΔS≠ values, a concerted mechanism with a four-membered hydrogen bonded cyclic transition state (11) is proposed for the title reaction series. It has been shown that the solvent change from water to acetonitrile for the aminolysis of 6 and 7 causes a mechanistic change from stepwise to concerted.
- Oh, Hyuck Keun,Ha, Joo Suk,Sung, Dae Dong,Lee, Ikchoon
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p. 8219 - 8223
(2007/10/03)
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- Episulfidation of strained cycloalkenes in the thermolysis of 5-aryloxy-1,2,3,4-thiatriazoles
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The thermolysis of 5-aryloxythiatriazoles 1 in the presence of norbornene (2a) and trans-cyclooctene (trans-2b) affords the corresponding thiiranes 3a and trans-3b in moderate yields. First-order kinetics are observed, suggesting that a sulfur intermediate, presumably dinitrogen sulfide, is generated in the fragmentation process of 1, which then serves as the active sulfur atom donor.
- Adam, Waldemar,Bargon
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p. 1959 - 1962
(2007/10/03)
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- The invention of radical reactions. Part XXIV. Relative rates of acylation and radical deoxygenation of secondary alcohols
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Secondary alcohols were transformed into various thiocarbonyl derivatives. Reduction of these compounds using tributyltin hydride and an initiator afforded the corresponding deoxy-compounds. Half-life and competitive measurements showed that all these reactions were fast and could be run to completion.
- Barton,Dorchak,Jaszberenyi
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p. 7435 - 7446
(2007/10/02)
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- IMPROVED METHODS FOR THE RADICAL DEOXYGENATION OF SECONDARY ALCOHOLS
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The reaction of Barton and McCombie has been improved by the use of the new reagents 2,4,6-trichlorophenoxythiocarbonyl chloride and its congener pentafluorophenoxythiocarbonyl chloride.Deoxygenations with these derivatives of 1,2:5,6-diacetoneglucofurano
- Barton, Derek H. R.,Jaszberenyi, Joseph Cs.
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p. 2619 - 2622
(2007/10/02)
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- Preparation of thiophenols from phenols
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Thiophenols are formed from phenols by first reacting a phenol with thiophosgene to form an aryl chlorothionoformate which is subjected to a halogen exchange reaction using an alkali metal fluoride to yield the corresponding fluorothionoformate. This fluo
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- NUCLEIC ACID RELATED COMPOUNDS. 42. A GENERAL PROCEDURE FOR THE EFFICIENT DEOXYGENATION OF SECONDARY ALCOHOLS. REGIOSPECIFIC AND STEREOSELECTIVE CONVERSION OF RIBONUCLEOSIDES TO 2 prime -DEOXYNUCLEOSIDES.
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Treatment of unhindered secondary alcohols with phenoxythiocarbonyl chloride (phenyl chlorothionocarbonate) in pyridine/dichloromethane, or in acetonitrile with 4-dimethylaminopyridine catalysis for hindered alcohols, gave clean conversion to their O-phenoxythiocarbonyl derivatives. Reductive deoxygenation of these phenyl thionocarbonate esters proceeded smoothly, using tri-n-butyltin hydride and a free radical initiator in warm toluene. Overall conversion yields ranged from 57 to 78% for the naturally occurring nucleosides, nucleoside antibiotics, and methyl beta -D-ribofuranoside.
- Robins,Wilson,Hansske
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p. 4059 - 4065
(2007/10/02)
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