- Substrate-Controlled Diastereoselective Synthesis of Sugar-Based Chlorinated Perhydrofuro[2,3-b]pyrans via Copper(I)-Catalyzed Radical Cyclization
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The work describes the first copper(I) chloride/2,2′-bipyridine-catalyzed atom transfer radical cyclization (ATRC) of unsaturated carbohydrate-derived chloroacetals to generate chlorinated perhydrofuro[2,3-b]pyrans via an effective diastereoselective route. Various glycals (glucal, galactal and lactal) underwent the Ferrier rearrangement with 2,2,2-trichloroethanols to give acetal precursors stereoselectively, R-selective with galactal in contrast to S-selective with glucal. The radical cyclization of the Ferrier products occurred smoothly to afford cis-fused bicyclic products with the transfer of the chlorine atom at the non-anomeric carbon in the cyclized radical intermediate predominantly from the equatorial direction. The carbohydrate templates controlled the stereochemistry of both Ferrier rearrangement and ATRC steps. The stereostructures of the products were also supported by single crystal X-ray diffraction crystallography. The products possess biologically important structural segments such as a glycosidic linkage, a fused bicyclic acetal unit and a chlorosugar unit which are potential sources for biological studies and further synthetic elaborations. (Figure presented.).
- Ram, Ram N.,Kumar, Neeraj,Gupta, Dharmendra Kumar
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Read Online
- A NEW ELECTROGENERATED BASE. CONDENSATION OF CHLOROFORM WITH ALIPHATIC ALDEHYDES
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A novel base was generated by electrochemical reduction of 2-pyrrolidone in DMF, and this electrogenerated base (EGB) was effective to promote the condensation of chloroform with aliphatic aldehydes in good yields.
- Shono, Tatsuya,Kashimura, Shigenori,Ishizaki, Kunihiko,Ishige, Osamu
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Read Online
- Optical Resolution of Tertiary Acetylenic Alcohols and Secondary Alcohols by Complexation with Achiral Amines
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Partially resolved tertiary acetylenic alcohols and secondary alcohols were easily resolved completely by complexation with achiral amines such as 1,4-diazabicyclooctane (DABCO), N,N'-dialkylpiperazine, N,N,N',N'-tetramethylethylenediamine, and pyrazine, to give optically pure enantiomers.Interestingly, DABCO formed more stable complex with optically pure enantiomers but the other amines formed more stable complex with racemic compounds.
- Toda, Fumio,Tanaka, Koichi
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Read Online
- Synthetic process of rosone
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The invention relates to a synthetic process of rosone. A solid super base is adopted as a catalyst during preparation of trichloromethyl benzyl alcohol, so that production of basic wastewater is avoided, product separation is facilitated, conversion rate of benzaldehyde is increased, the proportion of byproduct benzoic acid is reduced, and product yield is increased greatly and can be up to 95% or higher as the maximum.
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Paragraph 0023; 0025; 0026; 0029; 0032; 0034; 0036
(2018/07/30)
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- 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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- One-Carbon Homologation of Primary Alcohols and the Reductive Homologation of Aldehydes Involving a Jocic-Type Reaction
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(Trichloromethyl)carbinols, which are formed in one operation from either alcohols or aldehydes, can be converted into primary alcohols in a Jocic-type reaction involving LiBH4. The net result is a convenient two-step, one-carbon homologation of primary alcohols or a reductive one-carbon homologation of aldehydes featuring a broad substrate scope. The method is step-economical, and it nicely complements established one-carbon homologation strategies. (Trichloromethyl)carbinols, which are formed in one operation from either alcohols or aldehydes, can be converted into primary alcohols in a Jocic-type reaction involving LiBH4. The net result is a convenient two-step, one-carbon homologation of primary alcohols or a reductive one-carbon homologation of aldehydes featuring a broad substrate scope.
- Li, Zhexi,Gupta, Manoj K.,Snowden, Timothy S.
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p. 7009 - 7019
(2015/11/16)
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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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- Steric vs. electronic effects in the Lactobacillus brevis ADH-catalyzed bioreduction of ketones
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Lactobacillus brevis ADH (LBADH) is an alcohol dehydrogenase that is commonly employed to reduce alkyl or aryl ketones usually bearing a methyl, an ethyl or a chloromethyl as a small ketone substituent to the corresponding (R)-alcohols. Herein we have tested a series of 24 acetophenone derivatives differing in their size and electronic properties for their reduction employing LBADH. After plotting the relative activity against the measured substrate volumes we observed that apart from the substrate size other effects must be responsible for the activity obtained. Compared to acetophenone (100% relative activity), other small substrates such as propiophenone, α,α, α-trifluoroacetophenone, α-hydroxyacetophenone, and benzoylacetonitrile had relative activities lower than 30%, while medium-sized ketones such as α-bromo-, α,α-dichloro-, and α,α-dibromoacetophenone presented relative activities between 70% and 550%. Moreover, the comparison between the enzymatic activity and the obtained final conversions using an excess or just 2.5 equiv. of the hydrogen donor 2-propanol, denoted again deviations between them. These data supported that these hydrogen transfer (HT) transformations are mainly thermodynamically controlled. For instance, bulky α-halogenated derivatives could be quantitatively reduced by LBADH even employing 2.5 equiv. of 2-propanol independently of their kinetic values. Finally, we found good correlations between the IR absorption band of the carbonyl groups and the degrees of conversion obtained in these HT processes, making this simple method a convenient tool to predict the success of these transformations. The Royal Society of Chemistry.
- Rodriguez, Cristina,Borzecka, Wioleta,Sattler, Johann H.,Kroutil, Wolfgang,Lavandera, Ivan,Gotor, Vicente
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supporting information
p. 673 - 681
(2014/01/06)
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- Trichloromethyl ketones: Asymmetric transfer hydrogenation and subsequent Jocic-type reactions with amines
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Amino-amides are important pharmaceutical building-blocks. The enantioselective reduction of trichloromethyl ketones using ruthenium transfer hydrogenation catalysts is reported. The products react in a range of Jocic-type reactions to give enantiomerically enriched amino-amides.
- Perryman, Michael S.,Harris, Matthew E.,Foster, Jade L.,Joshi, Anushka,Clarkson, Guy J.,Fox, David J.
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supporting information
p. 10022 - 10024
(2013/10/22)
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- Transition-metal-free transformation of aryl bromides into aromatic esters and amides via aryl trichloromethyl ketones
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A variety of aryl bromides have been treated with Mg and then chloral, followed by tBuOCl and subsequently alcohols or amines to produce the corresponding aromatic esters or amides in good yields via the formation of aryl trichloromethyl ketones as intermediates. These reactions are examples of a transition-metal-free one-pot preparation of aromatic esters and amides from aryl bromides. Aryl bromides have been treated with Mg and then chloral, followed by tBuOCl or tBuOCl with I2 as an additive, and subsequently alcohols or amines to form the corresponding aromatic esters and aromatic amides via aryl trichloromethyl ketones as intermediates. Copyright
- Dohi, Souya,Moriyama, Katsuhiko,Togo, Hideo
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p. 7815 - 7822
(2013/12/04)
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- One-pot synthesis of trichloromethyl carbinols from primary alcohols
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Versatile trichloromethyl carbinols can be prepared in one pot from primary alcohols by treatment with Dess-Martin periodinane (DMP) in CHCl3 followed by introduction of commercially available 1,5,7-triazabicyclo[4.4.0] dec-5-ene (TBD). A modification of the method was used to convert chiral primary alcohol (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-methanol to the corresponding trichloromethyl carbinol with complete stereochemical fidelity, despite the reactant proceeding through a base-sensitive aldehyde intermediate.
- Gupta, Manoj K.,Li, Zhexi,Snowden, Timothy S.
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scheme or table
p. 4854 - 4860
(2012/07/30)
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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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- Fumigant antitermitic activity of plant essential oils and components from ajowan (Trachyspermum ammi), allspice (Pimenta dioica), caraway (Carum carvi), dill (Anethum graveoiens), geranium (Pelargonium graveoiens), and litsea (Litsea cubeba) oils against Japanese termite (Reticulitermes speratus kolbe)
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Plant essential oils from 26 plant species were tested for their insecticidal activities against the Japanese termite, Reticulitermes speratus Kolbe, using a fumigation bioassay. Responses varied with source, exposure time, and concentration. Among the essential oils tested, strong insecticidal activity was observed with the essential oils of ajowan (Trachyspermum ammi), allspice (Pimenta dioica), caraway (Carum carvi), dill (Anethum graveoiens), geranium (Pelargonium graveoiens), and litsea (Litsea cubeba). The composition of six essential oils was identified by using gas chromatographymass spectrometry. The compounds thus identified were tested individually for their insecticidal activities against Japanese termites. Responses varied in a dose-dependent manner for each compound. Phenol compounds exhibited the strongest insecticidal activity among the test compounds; furthermore, alcohol and aldehyde groups were more toxic than hydrocarbons. The essential oils and compounds described herein merit further study as potential fumigants for termite control. 2009 American Chemical Society.
- Seo, Seon-Mi,Kim, Junheon,Lee, Sang-Gil,Shin, Chang-Hoon,Shin, Sang-Chul,Park, Il-Kwon
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experimental part
p. 6596 - 6602
(2010/08/19)
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- General and practical conversion of aldehydes to homologated carboxylic acids
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(Chemical Equation Presented) The reaction of aldehydes with trichloromethide followed by sodium borohydride or sodium phenylseleno(triethyl) borate under basic conditions affords homologated carboxylic acids in high yields. This operationally simple procedure provides a practical, efficient alternative to other homologation protocols. The approach is compatible with sensitive aldehydes including enals and enolizable aldehydes. It also offers convenient access to α-monodeuterated carboxylic acids.
- Cafiero, Lauren R.,Snowden, Timothy S.
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supporting information; experimental part
p. 3853 - 3856
(2009/07/01)
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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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- Recoverable phase-transfer catalysts with fluorinated anions: Generation and reactions of dichlorocarbene and CCl3 anion in the heterogeneous system KOH(s)/CHCl3/nBu4NPF6
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Tetraalkylammonium salts bearing PF6- and BF 4- anions have been recognized as recoverable phase-transfer catalysts for the synthesis of 1,1-dichlorocyclopropane and α-(trichloromethyl) carbinol derivatives from alkenes or aldehydes in the heterogeneous system KOH(s)/CHCl3. The catalysts retained their catalytic activity over several reaction cycles. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Kryshtal, Galina V.,Zhdankina, Galina M.,Zlotin, Sergei G.
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experimental part
p. 1777 - 1782
(2009/04/11)
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- Trichloromethyltrimethylsilane, sodium formate, and dimethylformamide: A mild, efficient, and general method for the preparation of trimethylsilyl- protected 2,2,2-trichloromethylcarbinols from aldehydes and ketones
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(Chemical Equation Presented) New conditions for the preparation of trimethylsilyl-protected 2,2,2-trichloromethylcarbinols 2 from aldehydes and ketones are reported. Compounds 2, which are important intermediates in organic synthesis, were obtained in excellent yields by use of a combination of trichloromethyltrimethylsilane (TMSCCI3), and a catalytic amount of sodium formate (HCOONa) in dimethylformamide (DMF). Substrates bearing highly sensitive protecting groups have been successfully subjected to our conditions. We also describe a one-pot procedure that gives direct access to 2,2,2-trichloromethylcarbinols 3. This methodology avoids the use of strong bases usually required for the synthesis of 3 (Wyvratt et al. J. Org. Chem. 1987, 52, 944; Aggarwal and Mereu, J. Org. Chem. 2000, 65, 7211).
- Kister, Jeremy,Mioskowski, Charles
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p. 3925 - 3928
(2008/02/02)
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- Suzuki-Miyaura cross-coupling of 1,1-dichloro-1-alkenes with 9-alkyl-9-BBN
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We addressed an unexplored application of the Suzuki-Miyaura protocol to the cross-coupling of 1,1-dichloro-1-alkenes with 9-alkyl-9-BBN. The use of bisphosphine ligands with a large P-Pd-P bite angle allowed us to synthesize Z-chlorinated internal alkenes in good yields resulting from a selective monocoupling process, a recurrent challenge with 1,1-dichloro-1-alkenes. Moreover, these monochlorinated olefins could be further transformed providing stereospecifically trisubstituted olefins.
- Liron, Frederic,Fosse, Celine,Pernolet, Alban,Roulland, Emmanuel
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p. 2220 - 2223
(2007/10/03)
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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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- Reeve's synthesis of 2-imino-4-thiazolidinone from alkyl (aryl) trichloromethylcarbinol revisited, a three-component process from aldehyde, chloroform and thiourea
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An efficient synthesis of 2-imino-4-thiazolidinones from readily accessible alkyl (aryl) trichloromethylcarbinols and thioureas under mild conditions is reported. A one-pot three-component synthesis of the title compounds from aldehyde, chloroform and thiourea is also developed for the first time
- Blanchet, Jér?me,Zhu, Jieping
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p. 4449 - 4452
(2007/10/03)
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- FLAME RETARDANT POLYMERS
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The present invention is directed to novel flame retardant monomers and polymers, wherein the flame retardant properties of the polymers are provided by functionality in pendant groups attached to a polymer backbone (as opposed to the polymer backbone itself possessing flame retardant properties. The present invention is also directed to methods of making such polymers and monomers, and articles of manufacture incorporating such monomers and polymers.
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Page/Page column 14-15; 3/6
(2008/06/13)
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- Copper(I)-promoted dechlorinative Surzur-Tanner rearrangement of 2,2,2-trichloroethyl carboxylates
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(Matrix presented) 2,2,2-Trichloroethyl carboxylates undergo highly efficient dechlorinative Surzur-Tanner rearrangement with 2 equiv of a 1:1 molar mixture of CuCl and bpy in boiling DCE to give 1-chloroethenyl carboxylates in which copper appears to play an important role, probably by coordinating the initial radical or as a Lewis acid catalyst.
- Ram, Ram N.,Meher, Nabin Kumar
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p. 145 - 147
(2007/10/03)
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- A versatile synthesis of 2-haloalk-2(Z)-en-1-ols and 1-chloro-1(Z)-alkenes from trichloromethylcarbinols
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CrCl2 converts trichloromethylcarbinols under mild conditions to (E)-α-haloalkylidene chromium carbenoids which add to aldehydes or are quenched with water affording 2-haloalk-2(Z)-en-1-ols and 1-chloro-1(Z)-alkenes, respectively, in high yield.
- Baati, Rachid,Barma,Falck,Mioskowski, Charles
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p. 2183 - 2185
(2007/10/03)
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- A practical asymmetric synthesis of homochiral α-arylglycines
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Enantioselective reduction of a series of substituted aryl trichloromethyl ketones with the CBS-catecholborane reagent afforded homochiral aryl trichloromethyl carbinols which have been elaborated to give homochiral α-arylglycines in high e.e.
- Mellin-Morliere, Christelle,Aitken, David J.,Bull, Steven D.,Davies, Stephen G.,Husson, Henri-Philippe
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p. 149 - 155
(2007/10/03)
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- A new and practical synthesis of vinyl dichlorides via a non-Wittig-type approach
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A practical approach for the conversion of aldehydes to vinyl dichlorides has been developed. These are three-step, one-pot reactions involving the formation of trichlorocarbinol by treatment of aldehydes with trichloroacetic acid and sodium trichloroacetate followed by in situ protection and elimination reactions to form the desired vinyl dichlorides in 85 to 95% yields. (C) 2000 Dupont Pharmaceuticals Company.
- Wang, Zhe,Campagna, Silvio,Xu, Guoyou,Pierce, Michael E.,Fortunak, Joseph M.,Confalone, Pat N.
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p. 4007 - 4009
(2007/10/03)
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- Effective nucleophilic trifluoromethylation with fluoroform and common base
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Common bases (alcoholate, dimsyl anion or amide) are able to deprotonate trifluoromethane to form a trifluoromethyl anion equivalent. In this reaction DMF plays a crucial role of stabilisation Trifluoromethyl aryl alcohols, ketones or sulfides can be obtained in good yields with the new reagent CF3H/Base/DMF.
- Russell, Jamie,Roques, Nicolas
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p. 13771 - 13782
(2007/10/03)
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- Direct electroreduction or use of an electrogenerated base : Two ways for the coupling of polyhalogenated compounds with aldehydes or ketones
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The electrochemical coupling of polyhalogenated compounds with carbonyl compounds is achieved in two ways. A carbanion RX(n)- is generated either by the direct electroreduction of RX(n)Cl or by deprotonation of RX(n)H. In this latter case the base Ph- is electrogenerated by reduction of iodobenzene. All electrolysis were carried out in an undivided cell fitted with a cadmium-coated cathode and an aluminium or magnesium sacrificial anode.
- Barhdadi, Rachid,Simsen, Blandine,Troupel, Michel,Nedelec, Jean-Yves
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p. 1721 - 1728
(2007/10/03)
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- A NEW PREPARATIVE METHOD FOR OPTICALLY ACTIVE DIARYLCARBINOLS
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Some diarylcarbinols were resolved efficiently by complexation with brucine.
- Toda, Fumio,Tanaka, Koichi,Koshiro, Kenzo
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p. 873 - 874
(2007/10/02)
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- Process for preparing polyhalogenated carbinols
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There is disclosed a process for preparing polyhalogenated carbinols having formula: STR1 by reacting a compound having formula: STR2 with a system consisting of a compound having formula: STR3 and of a divalent metal or of a metal salt, in protic dipolar solvents, in which formulae R=H, an alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkadienyl, phenyl, naphthyl, anthracyl group, a heterocyclic radical, optionally substituted; R'=H, a haloalkyl, --CN, --COOR" group with R" equal to H or to an alkyl group; X1 =Cl, Br; =X2 =F, Cl, Br; X3 =Cl, Br, CF3, CCl3 ; Y=Br or Cl when X1, X2 and X3 are different from Br.
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- General and Efficient Synthesis of 1,1,1-Trichloro-2-alkanols
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1,1,1-Trichloroalkanols were readily obtained in good yields by reaction of trichloroacetic acid with aldehydes in hexamethylphosphoric triamide. 1,3-Dimethyl-2-imidazolidinone was found to be useful as an alternate solvent giving, however, lower yields.
- Ferraccioli, Raffaella,Gallina, Carlo,Giordano, Cesare
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p. 327 - 328
(2007/10/02)
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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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- TRICHLOROMETHYLATION OF CARBONYL COMPOUNDS IN THE PRESENCE OF CROWN ETHERS
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The reaction of potassium trichloroacetate with carbonyl compounds (aldehydes, acid anhydrides and chlorides) in acetonitrile in the presence of crown ethers leads to an increase of 11-19percent in the yield of the C-trichloromethylation products and reduces the reaction time by an order of magnitude.The macrocyclic perhydrodibenzo-18-crown-6-polyether, used as phase-transfer catalyst, is more effective than dibenzo-18-crown-6.
- Kyazimov, A. S.,Abdullabekov, I. M.,Karaev, S. F.
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p. 1456 - 1458
(2007/10/02)
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- Fluoride Ion-Catalyzed Generation and Carbonyl Addition of α-Halo Carbanions Derived from α-Halo Organosilicon Compounds
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The title carbanion species are generated from the corresponding α-haloorganosilicon compounds by the action of a catalytic amount of tris(diethylamino)sulfonium difluorotrimethylsilicate and are found to undergo addition to aldehyde carbonyl efficiently at ambient temperature.The synthetic potential of the reaction is demonstrated by application to the synthesis of some insecticides.
- Fujita, Makoto,Obayashi, Michio,Hiyama, Tamejiro
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p. 4135 - 4146
(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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- EINTOPFSYNTHESE TRICHLOROMETHYLSUBSTITUIERTER ALKOHOLE
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A new one-pot synthesis of alcohols RCH(OH)CCl3 starting from CCl4, Me3SiCl, Mg and aldehydes RCHO is described.
- Brunner, Henri,Wimmer, Peter
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- ELECTROSYNTHESIS OF ALCOHOLS FROM ORGANIC HALIDES AND KETONES OR ALDEHYDES
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The electrosynthesis of a wide range of alcohols from organic halides and ketones or aldehydes is achieved under simple and mild conditions in an undivided electrolytic cell using different sacrificial anodes.
- Sibille, Soline,d'Incan, Esther,Leport, Louis,Perichon, Jacques
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p. 3129 - 3132
(2007/10/02)
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- TRIMETHYLSILYL TRICHLOROACETATE: A NEW REAGENT FOR SALT-FREE SILYLATIONS
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Trimethylsylil trichloroacetate (1) is a convenient reagent for the silylation of phenols, carboxylic acids, mercaptans, amides, acetylenes, and β-keto esters, while the reaction of 1 with aldehydes and ketones affords silylated trichloromethyl carbinols (5).
- Renga, James M.,Pen-Chung, Wang
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p. 1175 - 1178
(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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- The Reaction of Trihalgenomethyl Anions with Carbonyl Compounds: Competitive Reactivity Comparisons and Applications to the Synthesis of α-Trihalogenomethyl Alcohols
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Trihalogenomethyl anions, generated by decarboxilation of trichloro- and tribromo-acetic acid in dimethyl sulphoxide solution, react with added aldehydes.In the presence of 1,3,5-trinitrobenzene, the reaction with aldehydes competes with the formation of the coloured Meisenheimer adduct.The reduction in absorbance from the value in the absence of aldehyde has been used tomeasure the reactivity of trihlogenomethyl anions towards a series of aldehydes relative to their reactivity towards trinitrobenzene.For 4-substituted benzaldehydes, the reactivities obey a linear p?- relationship.The most reactive aldehyde used is only two times less reactive towards CCl3(1-) or CBr3(1-) than hydrogen ions, and it is concluded that, in dimethyl sulphoxide solutions, the reaction between trichloromethyl anions and hydrogen ions is not encounter-controlled.The reactions with aldehydes have been used to prepare several new compounds of the formula RCH(OY)CX3 where R = aryl or pyridyl, X = Br or Cl, and Y = H or COCH3.
- Atkins, Paul J.,Gold, Victor,Wassef, Wasfy N.
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p. 1247 - 1252
(2007/10/02)
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- NOVEL SYNTHESIS OF CARBOHYDRATES USING ELECTROREDUCTION AS KEY REACTIONS
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Glyceraldehyde was transformed to threose, erythrose, and erythrulose using electroreduction as key reactions.
- Shono, Tatsuya,Ohmizu, Hiroshi,Kise, Naoki
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p. 4801 - 4804
(2007/10/02)
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- NOVEL SELECTIVE SYNTHESIS OF α-CHLOROMETHYL, α,α-DICHLOROMETHYL, AND α,α,α-TRICHLOROMETHYL KETONES FROM ALDEHYDE UTILIZING ELECTROREDUCTION AS KEY REACTIONS
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A variety of α-chloromethyl, α,α-dichloromethyl, and α,α,α-trichloromethyl ketones were synthesized from aldehyde utilizing cathodic reduction as key reactions.
- Shono, Tatsuya,Kise, Naoki,Yamazaki, Akira,Ohmizu, Hiroshi
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p. 1609 - 1612
(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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