- A novel β-(oxy)alkyl radical during copper(I)-mediated stereoselective synthesis of (Z)-ene-1,4-diones in a reaction of 2,2,2-trichloro-1-phenylethanone
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A novel β-(oxy)alkyl radical derived from trichloro methyl compound containing neither a suitably located C-C multiple bond nor a leaving group or a H-atom at the β-position of the radical in a reaction of 2,2,2-trichloro-1-phenyl-ethanone with 2 mol equiv each of CuCl and bpy in refluxing DCE under a N2 atm underwent intramolecular heterolysis (just like formation of intact radical cation-anion pair) during stereoselective radical dimerization to Z-ene-1,4-dione along with small amount of reductive dechlorination product. The stereochemistry was established by X-ray diffraction spectroscopy of various solid crystalline products.
- Ram, Ram N.,Tittal, Ram K.
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supporting information
p. 2437 - 2440
(2016/05/19)
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- β-(Carbonatoxy)alkyl radicals: A new subset of β-(ester)alkyl radical fragmentation during copper(I)-mediated synthesis of 1,1-dichloro-1-alkenes
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A new subset of β-(ester)alkyl radicals is presented. It is the first study on the chemistry of β-(alkoxycarbonyloxy)alkyl radicals that fill the gap in the spectrum of the migrating groups in β-(ester)alkyl radical reactions. The change from less nucleofugal (acetate) group to the more nucleofugal (carbonate) group in the spectrum of the migrating group changed the reaction path from rearrangement to fragmentation. This approach has been used for the synthesis of 1,1-dichloroalkenes in high yields. The formation of dichloroalkenes was accounted by the involvement of alkene radical cation and carbonate anion pair (a CIP) as a result of heterolysis of the CO bond of the carbonate at the β-position of the β-(alkoxycarbonyloxy)alkyl radical. The alkene radical cation was trapped by nucleophilic reaction with MeOH to form methyl ester.
- Ram, Ram N.,Tittal, Ram K.
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supporting information
p. 4342 - 4345
(2014/07/22)
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- Decarboxylative trichloromethylation of aromatic aldehydes and its applications in continuous flow
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Two new protocols for the efficient synthesis of 2,2,2- trichloromethylcarbinols, starting from aromatic aldehydes, have been developed. A combination of sodium trichloroacetate in the presence of malonic acid proved efficient for the transformation of el
- Jensen, Andreas B.,Lindhardt, Anders T.
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p. 1174 - 1183
(2014/03/21)
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- Platinum on carbon-catalyzed precise reduction control of trichloromethyl to Geminal-dichloromethyl groups
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Geminal-dichloromethyl derivatives could be efficiently synthesized by the highly chemoselective platinum on carbon-catalyzed mono-dechlorination of trichloromethyl substrates in dimethylacetamide (DMA) as a specific solvent at 25 °C under a hydrogen atmosphere. Copyright
- Imanishi, Takahiro,Fujiwara, Yuta,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
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supporting information; experimental part
p. 771 - 776
(2012/06/30)
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- Copper(I)-promoted synthesis of chloromethyl ketones from trichloromethyl carbinols
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(Chemical Equation Presented) Reaction of several trichloromethyl carbinols with 2 equiv of CuCl/bpy in refluxing DCE for 3 h afforded chloromethyl ketones in excellent yield by 1,2-H shift in the copper-chlorocarbenoid intermediate.
- Ram, Ram N.,Manoj
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p. 5633 - 5635
(2008/12/21)
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- PROCESS
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A process for the preparation of a compound of formula (I) wherein: R is an alkynyl group; R1 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkyl-alkyl, phenyl and phenylalkyl, it being possible in turn for all of the receding groups to carry one or more identical or different halogen atoms; alkoxy; alkenyloxy; alkynyloxy; alkoxyalkyl; haloalkoxy; alkylthio; haloalkylthio; alkysulfonyl; formyl; alkanoyl; hydroxy; halogen; cyano; nitro; amino; alkylamino; dialkylamino; carboxyl; alkoxycarbonyl; alkenyloxycarbonyl; or alkynyloxycarbonyl; and n is an integer from 0 to 3, said process comprising: (i) the reaction of a compound of formula (III) wherein R, R1 and n are as hereinbefore defined; m and m' are independently 0 or 1; when m and m' are both 0, A is an alkyl, alkenyl or alkynyl group (suitably having up to eight carbon atoms), optionally substituted by one or more groups independently selected from halogen, hydroxy, alkoxy, C1-4 dialkylamino or cyano; when one of m and m' is 0 and the other is 1, A is an alkanediyl, alkenediyl or alkynediyl group containing at least two carbon atoms (and suitably having up to eight carbon atoms), optionally substituted by one or more groups independently selected from halogen, hydroxy, alkoxy, C1-4 dialkylamino or cyano; when m and m' are both 1, A is an alkanetriyl, alkenetriyl or alkynetriyl group containing at least three carbon atoms (and suitably having up to eight carbon atoms), optionally substituted by one or more groups independently selected from halogen, hydroxy, alkoxy, C1-4 dialkylamino or cyano; and wherein if the group A contains three or more carbon atoms, one or more of the carbon atoms may each optionally be replaced with an oxygen atom, provided that there is at least one carbon atom between any two oxygen atoms in the molecule, with a compound of formula (IV) to give a compound of formula (II) wherein R, R1 and n are as hereinbefore defined, and (ii) the reaction of a compound of formula (II) with , wherein L is a leaving group, to give the compound of formula (I) as hereinbefore defined, is disclosed.
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Page/Page column 21
(2008/06/13)
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- Decomposition of sodium trichloroacetate in the presence of quaternary ammonium under microwave irradiation: A convenient one-pot synthesis of α-hydroxy acids in water
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A good yielding phase-transfer-catalyzed procedure for one-pot preparation of α-hydroxy acids from carbonyl compounds and sodium trichloroacetate by in situ addition and hydrolysis under microwave irradiation is described. Decomposition of sodium trichloroacetate is strongly accelerated by the presence of quaternary ammonium. The reaction can be conducted in water. Copyright Taylor & Francis Group, LLC.
- Yu, Haitao,Fang, Yun,Xia, Yongmei,Wu, Jing
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p. 2421 - 2426
(2007/10/03)
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- Reductive Addition of Polyhalomethanes and Their Related Compounds to Aldehydes and 1,2-Elimination of the Coupling Products in a Pb/Al Bimetal Redox System
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A Pb/Al bimetal system was used to carry out reductive addition of tetrachloromethane, tetrabromomethane, bromotrichloromethane, trichloroacetamide, and trichloroacetonitrile to aldehydes.Subsequent 1,2-elimination of the halogen atom and hydroxyl group from the coupling products was also performed with the Pb/Al bimetal system.The technology was successfully applied to stereocontrolled syntheses of ethyl trans- and cis-3-(2,2-dihaloethenyl)-2,2-dimethylcyclopropanecarboxylates.
- Tanaka, Hideo,Yamashita, Shiro,Yamanoue, Motoi,Torii, Sigeru
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p. 444 - 450
(2007/10/02)
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- CARBOXYLATION OF ARENES
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A two-step procedure for the carboxylation of aromatic rings is described, involving the intermediate preparation of 1-aryl-2,2,2-trichloroethanols (1), which form the corresponding benzoic acids by treatment with NaOH/H2O2.
- Menegheli, Paulo,Rezende, Marcos Caroli,Zucco, Cezar
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p. 457 - 464
(2007/10/02)
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- Chain Reactions Induced by Cathodic Reduction
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Cathodic reduction of a system comprising carbon tetrachloride, chloroform, and an aldehyde led to an effective anionic chain reaction.The best current efficiency observed was about 1*104 percent .Such a chain reaction is an effective synthetic method for 1,1,1-trichloro-2-alkanols.The reaction system consisting of methyl trichloroacetate, methyl dichloroacetate, and an aldehyde and several other systems also exhibited a similar pattern of chain reaction.
- Shono, Tatsuya,Kise, Naoki,Masuda, Mitsuharu,Suzumoto, Takeshi
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p. 2527 - 2533
(2007/10/02)
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- The Reaction of Polyhalogenomethanes with Aldehydes and with 1,3,5-Trinitrobenzene in the Presence of Tin(II) Salts: Evidence for the Formation of Trihalogenomethyl Anions
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The (previously reported) formation of 2,2,2-tribromoethanols by the reaction of aromatic aldehydes with tetrabromomethane in the presence of tin(II) fluoride in dimethyl sulphoxide solution also occurs when tin(II) chloride is used in place of the fluoride.Analogous reactions occur with certain other tetrahalogenomethanes, but not with trihalogenomethanes nor with fluorine-containing tetrahalogenomethanes.When the aldehyde is replaced by 1,3,5-trinitrobenzene, Meisenheimer adducts derived from trihalogenomethyl anions are formed.The trihalogenomethyl anions are thought to be a product of the two-electron reduction of tetrahalogenomethanes by tin (II).
- Atkins, Paul J.,Gold, Victor,Routledge, Paul J.
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p. 1563 - 1566
(2007/10/02)
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- A NOVEL CHAIN REACTION INDUCED BY CATHODIC REDUCTION. ADDITION OF TRICHLOROMETHYL ANION TO ALDEHYDES OR VINYL ACETATE
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A novel chain reaction induced by cathodic reduction was found in the reaction system consisting of carbon tetrachloride, chloroform, and electrophiles such as aldehydes or vinyl acetate.The current efficiency of addition of trichloromethyl anion to electrophiles was extremely high.Synthesis of an analogue of ethyl chrysanthemate using this new reaction was also described.
- Shono, Tatsuya,Ohmizu, Hiroshi,Kawakami, Souta,Nakano, Shinji,Kise, Naoki
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p. 871 - 874
(2007/10/02)
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- Studies on the rearrangement of (trichloromethyl)carbinols to α-chloroacetic acids
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Phenyl(trichloromethyl)carbinol undergoes an unimolecular, predominantly intramolecular conversion into potassium α-chlorophenylacetate on stirring with 10percent aqueous potassium hydroxide at 0 deg C for several days.Besides providing an interesting example of a 1-2 chlorine shift, the reaction is of potential importance for the synthesis of α-chloro acids.The study of a variety of (trichloromethyl)carbinols shows the reaction is general for secondary (trichloromethyl)carbinols as well as trichloroethanol.The mechanism of the reaction involves the preliminary formation of an epoxide.Several mechanisms are considered for the conversion of the epoxide to the α-chloroacetate anion, but none accounts for all of the experimental facts.Tertiary carbinols break down at the epoxide stage into a ketone and carbon monoxide.
- Reeve, Wilkins,McKee, James R.,Brown, Robert,Lakshmanan, Sitarama,McKee, Gertrude A.
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p. 485 - 493
(2007/10/02)
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