- A user-friendly procedure for the preparation of secondary alkyl chlorides
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Secondary alkyl chlorides have been efficiently prepared from secondary alkyl sulfonates under mild and user-friendly conditions. The exchange reaction was generally performed by using benzyltributylammonium chloride in acetone (reflux, 30 min). Yields are excellent from functionalized, base-sensitive and hindered secondary alkyl sulfonates. Georg Thieme Verlag Stuttgart New York.
- Cahiez, Gerard,Lefevre, Nicolas,Poizat, Mael,Moyeux, Alban
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- Ionic-Liquid-Supported 1,3-Dimethylimidazolidin-2-one: Application as a Reusable Halogenation Reagent
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We describe the synthesis of ionic-liquid-supported 1,3-dimethylimidazolidin-2-one, together with the halogenation of alcohols in a reaction system in which this reagent is combined with oxalyl chloride. A new method was established that does not require additives such as bases, and which permits the ready isolation and purification of the product. Good conversions were obtained, and good reusability of the reagent was observed.
- Koguchi, Shinichi,Shibuya, Yuga,Igarashi, Yusuke,Takemura, Haruka
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- Catalytic conversions of chloroolefines over iron oxide nanoparticles 3. Electronic and magnetic properties of γ-Fe2O3 nanoparticles immobilized on different silicas
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Catalytic properties of superparamagnetic γ-ferric oxide nanoclusters, which are uniform in terms of size and magnetic properties were studied. The catalysts were supported on the activated silica gel matrix (AGM) prepared from the KSK-2 silica gel of globular structure and on the activated silica matrix (ASM) prepared from layered natural vermiculite. The clusters are active in some reactions of chloroolefin conversions: isomerization of dichlorobutenes and alkylation of benzene with allyl chloride. Their activity in these reactions is many times higher that of usual supported catalysts based on α-ferric oxide. Analysis of the Moessbauer spectra of the 2.5 wt.% Fe/AGM and 2.5 wt.%Fe/ASM samples before and after the reaction at T = 3-300 K shows that during the reaction some FeIII ions arranged in ~2-3-nm γ-Fe2O3 nanoclusters magnetically ordered at 6 K are reduced to form a high-spin FeII complex in the paramagnetic state. According to the macroscopic magnetization data (SQUID) of the initial clusters, curves with hysteresis are observed at 2 K in the plots of forward and backward magnetization, while the 2.5 wt.%Fe/ASM catalyst after the reaction at T = 2 K demonstrates a linear field dependence of the magnetization passing through the coordinate origin. Analysis of the Moessbauer spectra and magnetic properties suggests that during the catalytic reaction the Fe III ions in the γ-Fe2O3 nanoclusters interact with chloroolefin with the allylic structure to be partially reduced to the FeII ions that are bound in a complex containing chloride ions and OII ion(s) of the silicate matrix as ligands. This is a reason, probably, for the high catalytic activity of γ-Fe2O3 nanoparticles.
- Rostovshchikova,Kiseleva,Smirnov,Maksimov,Suzdalev,Prusakov,Tsodikov,Ikorskii
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- Metal-free regioselective hydrochlorination of unactivated alkenes via a combined acid catalytic system
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A combined acid HCl/DMPU-acetic acid catalytic system was used in the hydrochlorination of a wide range of unactivated alkenes. This hydrochlorination strategy is remarkably greener than previous reported methods in terms of high atom efficiency, no toxic waste generated and metal-free process. The higher efficiency, compared with other commercially available HCl reagents, was augmented by the good regioselectivity and functionality tolerance found. A stepwise mechanism for this hydrochlorination process was proposed based on kinetic studies.
- Liang, Shengzong,Hammond, Gerald B.,Xu, Bo
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supporting information
p. 680 - 684
(2018/02/14)
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- Ferric(III) Chloride Catalyzed Halogenation Reaction of Alcohols and Carboxylic Acids Using α,α-Dichlorodiphenylmethane
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A new method for chlorination of alcohols and carboxylic acids, using α,α-dichlorodiphenylmethane as the chlorinating agent and FeCl3 as the catalyst, was developed. The method enables conversions of various alcohols and carboxylic acids to their corresponding alkyl and acyl chlorides in high yields under mild conditions. Particulary interesting is the observation that the respective alkyl bromides and iodides can be generated from alcohols when either LiBr or LiI are present in the reaction mixtures.
- Lee, Chang-Hee,Lee, Soo-Min,Min, Byul-Hana,Kim, Dong-Su,Jun, Chul-Ho
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supporting information
p. 2468 - 2471
(2018/04/25)
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- The direct anti-Markovnikov addition of mineral acids to styrenes
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The direct anti-Markovnikov addition of strong Bronsted acids to alkenes remains an unsolved problem in synthetic chemistry. Here, we report an efficient organic photoredox catalyst system for the addition of HCl, HF and also phosphoric and sulfonic acids to alkenes, with complete regioselectivity. These transformations were developed using a photoredox catalyst in conjunction with a redox-active hydrogen atom donor. The nucleophile counterion plays a critical role by ensuring high reactivity, with 2,6-lutidinium salts typically furnishing the best results. The nature of the redox-active hydrogen atom donor is also consequential, with 4-methoxythiophenol providing the best reactivity when 2,6-lutidinium salts are used. A novel acridinium sensitizer provides enhanced reactivity within several of the more challenging reaction manifolds. This Article demonstrates how nucleophilic addition reactions mediated by photoredox catalysis can change the way electrophilic and homofugal precursors are constructed.
- Wilger, Dale J.,Grandjean, Jean-Marc M.,Lammert, Taylor R.,Nicewicz, David A.
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p. 720 - 726
(2014/08/05)
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- Enantioselective catalytic lithiation using a chiral binaphthyl derivative as electron carrier
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The lithiation, of the secondary chloride 2, catalyzed by binaphthyl derivatives, i.e. BINAM 4, BINOL 5, BINAP 6, H8-BINAP 7, Tol-BINAP 8, 2,2'-bis(pyrrolidin-1-yl)-1,1'-binaphthalene 9, and 2,2'-dimethyl-1,1'- binaphthalene 11, in the presence of different ketones has been studied, yielding the corresponding alcohol derivatives 3 and 12-16 in moderate to good yields. Binaphthyl derivative 11 has revealed to be very active as catalyst in the lithiation process at room temperature, and has allowed the preparation of the alcohol derivatives with enantioselectivities up to 50%.
- Martinez, Regina,Pastor, Isidro M.,Yus, Miguel
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- Triphosgene-amine base promoted chlorination of unactivated aliphatic alcohols
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Unactivated α-branched primary and secondary aliphatic alcohols have been successfully transformed into their corresponding alkyl chlorides in high yields upon treatment with a mixture of triphosgene and pyridine in dichloromethane at reflux. These mild chlorination conditions are high yielding, stereospecific, and well tolerated by numerous sensitive functionalities. Furthermore, no nuisance waste products are generated in the course of the reactions.
- Villalpando, Andres,Ayala, Caitlan E.,Watson, Christopher B.,Kartika, Rendy
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p. 3989 - 3996
(2013/06/04)
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- Efficient procedures to prepare primary and secondary alkyl halides from alkanols via the corresponding sulfonates under mild conditions
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The study presented herein shows that sulfonate/halide exchange can be advantageously performed in THF to avoid several side reactions such as elimination and epimerization when the reaction is performed from a chiral alkyl sulfonate or a substrate having a C-H acidic chiral center. The main limitation of this procedure was found to be the conversion of secondary alkyl sulfonates to alkyl chlorides. In this case, the addition of a catalytic amount of manganese chloride clearly accelerates the rate and the efficiency of the reaction. Copyright
- Cahiez, Gerard,Gager, Olivier,Moyeux, Alban,Delacroix, Thomas
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supporting information; experimental part
p. 1519 - 1528
(2012/07/03)
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- A facile and green protocol for nucleophilic substitution reactions of sulfonate esters by recyclable ionic liquids [bmim][X]
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Ionic liquids [bmim][X] (X = Cl, Br, I, OAc, SCN) are highly efficient reagents for nucleophilic substitution reactions of sulfonate esters derived from primary and secondary alcohols. The counter anions (X-) of the ionic liquids, [bmim][X], effectively replace the sufonates affording the corresponding substitution products such as alkyl halides, acetates, and thiocyanides in excellent yields. The newly developed protocol is very environmentally attractive because the reactions use stoichiometric amounts of ionic liquids as sole reagents in most cases and do not require additional solvents, any other activating reagents, non-conventional equipment, or special precautions. Moreover, these ionic liquids can be readily recycled without loss of reactivity, making the whole process greener.
- Liu, Yajun,Xu, Yongnan,Jung, Sun Ho,Chae, Junghyun
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p. 2692 - 2698,7
(2012/12/12)
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- A facile and green protocol for nucleophilic substitution reactions of sulfonate esters by recyclable ionic liquids [bmim][X]
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Ionic liquids [bmim][X] (X = Cl, Br, I, OAc, SCN) are highly efficient reagents for nucleophilic substitution reactions of sulfonate esters derived from primary and secondary alcohols. The counter anions (X-) of the ionic liquids, [bmim][X], effectively replace the sufonates affording the corresponding substitution products such as alkyl halides, acetates, and thiocyanides in excellent yields. The newly developed protocol is very environmentally attractive because the reactions use stoichiometric amounts of ionic liquids as sole reagents in most cases and do not require additional solvents, any other activating reagents, non-conventional equipment, or special precautions. Moreover, these ionic liquids can be readily recycled without loss of reactivity, making the whole process greener. Georg Thieme Verlag KG Stuttgart · New York.
- Liu, Yajun,Xu, Yongnan,Jung, Sun Ho,Chae, Junghyun
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p. 2692 - 2698
(2013/01/15)
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- Chlorination of aliphatic primary alcohols via triphosgene-triethylamine activation
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Activation of primary aliphatic alcohols with triphosgene and triethylamine mixtures afforded either alkyl chloride or diethylcarbamate products, and the switch in selectivity appeared to be driven by sterics. The reaction conditions to achieve this highly useful transformation were unexceptionally mild and readily tolerated by a wide range of sensitive functionalities.
- Ayala, Caitlan E.,Villalpando, Andres,Nguyen, Alex L.,McCandless, Gregory T.,Kartika, Rendy
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supporting information; experimental part
p. 3676 - 3679
(2012/09/08)
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- Chlorination of various substrates in subcritical carbon tetrachloride
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Various aliphatic hydrocarbons and the side chains of aromatic hydrocarbons were chlorinated in subcritical carbon tetrachloride. Chlorination of aromatic compounds including 1,4-disubstituted benzenes was investigated. Ketones and sulfones were stable under the employed conditions. Sulfoxides were converted into sulfides in a low to modest yields. The coupling adducts between olefins and carbon tetrachloride were obtained from the reactions of olefins.
- Tanemura, Kiyoshi,Suzuki, Tsuneo,Nishida, Yoko,Horaguchi, Takaaki
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scheme or table
p. 2881 - 2888
(2010/06/16)
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- Aromatic cation activation of alcohols: Conversion to alkyl chlorides using dichlorodiphenylcyclopropene
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(Chemical Equation Presented) A novel paradigm for the activation of alcohols toward nucleophilic displacement via formation of cyclopropenium ethers is described. The conversion of a range of alcohol substrates to the corresponding alkyl chlorides occurs rapidly upon treatment with 3,3-dichloro-1,2-diphenylcyclopropene. 1H NMR data support the intermediacy of a cyclopropenium intermediate, and the reaction is demonstrated to proceed primarily via the SN2 mechanism for 1-phenylethanol. A total of 12 examples of substrate scope are provided.
- Kelly, Brendan D.,Lambert, Tristan H.
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supporting information; experimental part
p. 13930 - 13931
(2009/12/25)
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- Direct chlorination of alcohols with chlorodimethylsilane catalyzed by a gallium trichloride/tartrate system under neutral conditions
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The reaction of secondary alcohols 1 with chlorodimethylsilane (HSiMe 2Cl) proceeded in the presence of a catalytic amount of GaCl 3/diethyl tartrate to give the corresponding organic chlorides 3. In the catalytic cycle, the reaction of diethyl tartrate 4a with HSiMe 2Cl 2 gives the chlorosilyl ether 5 with generation of H2. Alcohol-exchange between the formed chlorosilyl ether 5 and the substrate alcohol 1 affords alkoxychlorosilane 6, which reacts with catalytic GaCl 3 to give the chlorinated product 3. The moderate Lewis acidity of GaCl3 facilitates chlorination. Strong Lewis acids did not give product due to excessive affinity for the oxy-functionalities. Although tertiary alcohols were chlorinated by this system even in the absence of diethyl tartrate, certain alcohols that are less likely to give carbocationic species were effectively chlorinated using the GaCl3/diethyl tartrate system. The Royal Society of Chemistry.
- Yasuda, Makoto,Shimizu, Kenji,Yamasaki, Satoshi,Baba, Akio
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supporting information; experimental part
p. 2790 - 2795
(2009/02/03)
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- NUCLEOPHILE ASSISTING LEAVING GROUPS
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Sulfonate leaving groups include a cation chelating moiety, e.g. a polyether or crown ether. The chelating moiety stabilizes the sulfonate leaving group by forming a complex with a cation of a cation-nucleophile combination. The stabilized leaving group is more easily displaced under many conditions than are standard arylsulfonate leaving groups such as the toxyl group. The chelating moiety also favors certain cations depending on the identity of the moiety thereby enhancing the reaction rate with nucleophilic salts containing the preferred cation. Use of the inventive leaving groups results in improved yields, decreased reaction times and improved product purity.
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Page/Page column 14-15
(2010/11/08)
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- Arylsulfonate-based nucleophile assisting leaving groups
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The synthesis and unique reactivity of a series of arylsulfonate-based nucleophile assisting leaving groups (NALG) containing oligomeric ether units (including crown ethers) attached to the arylsulfonyl ring in the ortho orientation are described. The reactions of a variety of these ether-containing alkyl sulfonates with metal halides proceeded at substantially greater rates than electronically similar sulfonates. These ether-containing leaving groups also displayed marked selectivity for lithium halides relative to the corresponding sodium and potassium salts in nucleophilic displacement reactions.
- Lepore, Salvatore D.,Bhunia, Anjan K.,Cohn, Pamela
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p. 8117 - 8121
(2007/10/03)
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- Indium-catalyzed direct chlorination of alcohols using chlorodimethylsilane-benzil as a selective and mild system
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The InCl3-catalyzed reaction of alcohols with chlorodimethylsilane (HSiMe2Cl) in the presence of benzil gave the corresponding organic chlorides under mild conditions. Benzil significantly changes the reaction course because the reducing product through dehydroxyhydration was obtained in the absence of benzil. The secondary or tertiary alcohols were effectively chlorinated. The substrates bearing acid-sensitive functional groups were also applied to this system. The highly selective chlorination of the tertiary site was observed in the competitive reaction between tertiary and primary alcohols. The highly coordinated hydrosilane generated from benzil and HSiMe2Cl is an important intermediate. Copyright
- Yasuda, Makoto,Yamasaki, Satoshi,Onishi, Yoshiyuki,Baba, Akio
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p. 7186 - 7187
(2007/10/03)
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- Interpretation of retention indices in gas chromatography for establishing structures of isomeric products of alkylarenes radical chlorination
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By an example of previously uncharacterized products obtained by alkylarenes radical chlorination was demonstrated that combination of various interpretation methods applied to the retention indices (RI) in the gas chromatography on the standard nonpolar phases (comparison of RI of products and initial compounds, characteristics of succession of the chromatographic elution of the structural isomers with the use of estimation of molecular dynamic parameters, application of the additive schemes to RI calculation, and using of structural analogy CH3?Cl for testing the results obtained) permitted unambiguous identification of the structure even without data of mass spectrometry.
- Zenkevich
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p. 270 - 280
(2007/10/03)
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- Nucleophilic substitution of 1-phenyl-2-phenyl telluropropane to yield 2-halo-1-phenylpropanes
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Mechanism of a novel transformation of the alkyl phenyltellurides to alkyl halides via nucleophilic substitution of the phenyltelluro group in organotelluriums is studied on the basis of kinetics and stereochemistry using the titled chiral substrate. The results obtained strongly suggest that the substitutions proceed via SN2 mechanism with Walden inversion and very low Arrhenius' energies of activation.
- Ogura, Fumio,Okada, Yoshiharu,Nishimura, Naoko,Hamamoto, Kenichiro,Miyakawa, Makoto,Otsubo, Tetsuo,Aso, Yoshio,Inoue, Shinobu,Tsutsui, Koji
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p. 203 - 210
(2007/10/03)
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- Direct Allylation of Aromatic Compounds with Allylic Chloride using the Supported Reagents System ZnCl2/SiO2-K2CO3/Al2O3
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Although the reaction of aromatic compounds with allylic chlorides using ZnCl2/SiO2, gives 2-chloro-1-arylalkanes accompanied with diarylalkanes, similar reaction using ZnCl2/SiO2-K2CO3/Al2O3 produces the monoallylated compound as the major product in good yield.
- Kodomari, Mitsuo,Nawa, Satoru,Miyoshi, Tadahiro
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p. 1895 - 1896
(2007/10/02)
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- Activation of the silicon-halogen bond by bismuth (III) halides. Halogenation of alcohols: prospective and mechanism
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In the presence of catalytic amount of BiCl3, chloromethylsylanes can be used as chlorinating agents for alcohols, and as chloro-dealkylating agents for silyl ethers and carboxylic and sulfonic esters.The chlorination of (R)-(-)-octan-2-ol and the (R)-(-)-2-mesyloctane by TMSCl gave predominantly the (S)-(+)-2-chlorooctane with inversion of configuration at secondary carbon.According to the class of alcohol, the mechanism involves SN2, SN2' or SN1 processes.This new activation of the Si-Cl bond, probably trough a Si-Cl...BiCl3 interaction gives a hard-soft reagent that can generate a silicenium cation, was also observed with Me3SiBr, BiBr3 and Me3SiI, BiI3 systems.The reaction is also presented as a possible alcoholysis of chlorosilanes, which can lead to siloxanes in non-aqueous conditions. catalysis / halogenation / alcohol / ester / silyl ether / chlorosilane / chlorotrimethylsilane / bromotrimethylsilane / iodotrimethylsilane / siloxane / bismuth (III) halide
- Labrouillere, Mireille,Roux, Christophe Le,Oussaid, Abdelouahad,Gaspard-Iloughmane, Hafida,Dubac, Jacques
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p. 522 - 530
(2007/10/02)
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- Phencyclidine-like Effects of Tetrahydroisoquinolines and Related Compounds
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A series of 1,2,3,4-tetrahydroisoquinolines, tetrahydrothienopyridines, and related compounds were evaluated for their ability to inhibit binding of -1--N-allylnormetazocine to phencyclidine (PCP) and ? receptors, respectively.A representative series of compounds was evaluated in behavioral assays to determine the ability of the compounds to induce PCP-like stereotyped behavior and ataxia.All of the compounds caused stereotyped behavior and ataxia, indicating their agonist actions at the PCP site.
- Gray, Nancy M.,Cheng, Brian K.,Mick, Stephen J.,Lair, Cecelia M.,Contreras, Patricia C.
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p. 1242 - 1248
(2007/10/02)
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- Retentive Friedel-Crafts Alkylation of Benzene with Optically Active 2-Chloro-1-phenylpropane and 1-Chloro-2-phenylpropane
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Alkylations of benzene with both (-)-2-chloro-1-phenylpropane (1) and (+)-1-chloro-2-phenylpropane (2) in the presence of Lewis acid gave the same products: (-)-1,2-diphenylpropane (3), 1,1-diphenylpropane, and polymeric materials. In these reactions, (-)-3 was obtained in 45-100percent optical yield and was not racemized under the conditions used. These results reveal that the reaction from 1 to 3 proceeds with retention of configuration and that from 2 to 3 with inversion. The stereochemistry of the alkylation with 1 is elucidated by the mechanism involving a neighboring phenyl ?-assisted cation; benzene attacks only the β-carbon of 1 from the side on which the previously attached chloride anion is located. The result of the reaction with 2 can be explained by a process involving the 1,2-shift of phenyl group in the ionization step of 2, followed by the formation of the same intermediate as in the reaction with 1. The mechanism of the overall reaction is discussed.
- Masuda, Shinji,Nakajima, Tadashi,Suga, Sohei
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p. 1089 - 1094
(2007/10/02)
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