- Mechanism of dichlorination of n-dodecane and chlorination of 1-chlorododecane adsorbed on ZSM-5 zeolite molecular sieves. A supramolecular structural interpretation
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The product distributions produced by the photoinduced dichlorination of n-dodecane (nD) and the photoinduced monochlorination of 1-chlorododecane (1CD) adsorbed on two pentasil zeolites (silicalite and LZ-105) have been investigated. The results are explained in terms of a supramolecular model for which the mobile and diffusing chlorination reagents (Cl?/Cl2) enter the zeolite particle from the external surface and diffuse preferentially along the linear channels of the zeolite internal surface that contain immobile adsorbed nD (or 1CD) molecules. The model assumes that the outermost layer of adsorbed substrates is attacked preferentially, that the attack occurs at the proximal end of adsorbed nD molecules closest to the external surface, and that, after the first chlorination, the substrate molecules in an inner layer are protected from chlorination by "blocking" molecules parked in the outer layer. The model describes each substrate molecule adsorbed on the internal surface in terms of supramolecular isomeric structures that are capable of characterizing the specific void space sites occupied by the substrate. A detailed analysis of the results allows the conclusion that the compensating cations tend to be preferentially located in the zigzag channels rather than in the linear channels or intersections and that the variation of selectivity of chlorination with experimental conditions results from redistribution of the isomeric supramolecular structures.
- Turro, Nicholas J.,Han, Nianhe,Lei, Xue-Gong,Fehlner, James R.,Abrams, Lloyd
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Read Online
- Photochlorination of n-Alkanes Adsorbed on Pentasil Zeolites
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The photochlorination of n-alkanes adsorbed on pentasil zeolites proceeds with up to a 20-fold greater selectivity for the monochlorination of terminal methyl groups compared to the selectivity observed when the reaction is carried out in a homogeneous solution.This enhanced selectivity, which provides a novel means of synthesizing terminally functionalized linear alkanes, was found to be a function of the percent loading of the alkane on the zeolite, the zeolite's silicon to aluminum ratio, the percent conversion of the starting material, and the water content of the zeolite.
- Turro, Nicholas J.,Fehlner, James R.,Hessler, Diane P.,Welsh, Kevin M.,Ruderman, Warren,et al.
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Read Online
- Catalytic remote hydrohalogenation of internal alkenes
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Primary alkyl halides have broad utility as fine chemicals in organic synthesis. The direct halogenation of alkenes is one of the most efficient approaches for the synthesis of these halides. Internal alkenes, in particular mixtures of isomers from refine
- Li, Xiang,Jin, Jianbo,Chen, Pinhong,Liu, Guosheng
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p. 425 - 432
(2022/02/07)
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- Lewis Base Catalysis Enables the Activation of Alcohols by means of Chloroformates as Phosgene Substitutes
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Nucleophilic substitutions (SN) are typically promoted by acid chlorides as sacrificial reagents to improve the thermodynamic driving force and lower kinetic barriers. However, the cheapest acid chloride phosgene (COCl2) is a highly toxic gas. Against this background, phenyl chloroformate (PCF) was discovered as inherently safer phosgene substitute for the SN-type formation of C?Cl and C?Br bonds using alcohols. Thereby, application of the Lewis bases 1-formylpyrroldine (FPyr) and diethylcyclopropenone (DEC) as catalysts turned out to be pivotal to shift the chemoselectivity in favor of halo alkane generation. Primary, secondary and tertiary, benzylic, allylic and aliphatic alcohols are appropriate starting materials. A variety of functional groups are tolerated, which includes even acid labile moieties such as tert-butyl esters and acetals. Since the by-product phenol can be isolated, a recycling to PCF with inexpensive phosgene would be feasible on a technical scale. Eventually, a thorough competitive study demonstrated that PCF is indeed superior to phosgene and other substitutes.
- Zoller, Ben,Stach, Tanja,Huy, Peter H.
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p. 5637 - 5643
(2020/09/21)
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- Formamide-Catalyzed Nucleophilic Substitutions: Mechanistic Insight and Rationalization of Catalytic Activity
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Herein, detailed mechanistic investigations into formamide-catalyzed nucleophilic substitution (SN) of alcohols are reported. Alkoxyiminium chlorides and hexafluorophosphates were synthesized and characterized as a key intermediate of the catalytic cycle. The determination of reaction orders and control experiments indicated that the nucleophilic attack of the formamide catalyst onto the reagent BzCl is the rate-determining step. Linear free energy relationship revealed a correlation between the quantified Lewis basicity strength of formamides by means of 11B NMR spectroscopy and their catalytic activity in SN-transformations. The observed difference in catalytic ability was attributed to the natural bond order charge, dipole moment, and Sterimol parameter B5. Importantly, this rationalization enables the prediction of the capacity of formamides to promote SN-type transformations in general.
- Hilt, Gerhard,Huy, Peter H.,Kohlmeyer, Corinna,Sch?fer, André
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p. 11567 - 11577
(2020/11/17)
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- A General Catalytic Method for Highly Cost- and Atom-Efficient Nucleophilic Substitutions
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A general formamide-catalyzed protocol for the efficient transformation of alcohols into alkyl chlorides, which is promoted by substoichiometric amounts (down to 34 mol %) of inexpensive trichlorotriazine (TCT), is introduced. This is the first example of a TCT-mediated dihydroxychlorination of an OH-containing substrate (e.g., alcohols and carboxylic acids) in which all three chlorine atoms of TCT are transferred to the starting material. The consequently enhanced atom economy facilitates a significantly improved waste balance (E-factors down to 4), cost efficiency, and scalability (>50 g). Furthermore, the current procedure is distinguished by high levels of functional-group compatibility and stereoselectivity, as only weakly acidic cyanuric acid is released as exclusive byproduct. Finally, a one-pot protocol for the preparation of amines, azides, ethers, and sulfides enabled the synthesis of the drug rivastigmine with twofold SN2 inversion, which demonstrates the high practical value of the presented method.
- Huy, Peter H.,Filbrich, Isabel
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supporting information
p. 7410 - 7416
(2018/04/30)
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- Systematic Evaluation of Sulfoxides as Catalysts in Nucleophilic Substitutions of Alcohols
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Herein, a method for the nucleophilic substitution (SN) of benzyl alcohols yielding chloro alkanes is introduced that relies on aromatic sulfoxides as Lewis base catalysts (down to 1.5 mol-%) and benzoyl chloride (BzCl) as reagent. A systematic screening of various sulfoxides and other sulfinyl containing Lewis bases afforded (2-methoxyphenyl)methyl sulfoxide as optimal catalyst. In contrast to reported formamide catalysts, sulfoxides also enable the application of plain acetyl chloride (AcCl) as reagent. In addition, it was demonstrated that weakly electrophilic carboxylic acid chlorides like BzCl promote Pummerer rearrangement of sulfoxides already at room temperature. This side-reaction also provided the explanation, why sulfoxide catalyzed SN-reactions of alcohols do not allow the effective production of aliphatic and electron deficient chloro alkanes. Comparison experiments provided further insight into the reaction mechanism.
- Motsch, Sebastian,Schütz, Christian,Huy, Peter H.
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supporting information
p. 4541 - 4547
(2018/09/13)
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- Nucleophilic Substitutions of Alcohols in High Levels of Catalytic Efficiency
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A practical method for the nucleophilic substitution (SN) of alcohols furnishing alkyl chlorides, bromides, and iodides under stereochemical inversion in high catalytic efficacy is introduced. The fusion of diethylcyclopropenone as a simple Lewis base organocatalyst and benzoyl chloride as a reagent allows notable turnover numbers up to 100. Moreover, the use of plain acetyl chloride as a stoichiometric promotor in an invertive SN-type transformation is demonstrated for the first time. The operationally straightforward protocol exhibits high levels of stereoselectivity and scalability and tolerates a variety of functional groups.
- Stach, Tanja,Dr?ger, Julia,Huy, Peter H.
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supporting information
p. 2980 - 2983
(2018/05/28)
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- Formamides as Lewis Base Catalysts in SNReactions—Efficient Transformation of Alcohols into Chlorides, Amines, and Ethers
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A simple formamide catalyst facilitates the efficient transformation of alcohols into alkyl chlorides with benzoyl chloride as the sole reagent. These nucleophilic substitutions proceed through iminium-activated alcohols as intermediates. The novel method, which can be even performed under solvent-free conditions, is distinguished by an excellent functional group tolerance, scalability (>100 g) and waste-balance (E-factor down to 2). Chiral substrates are converted with excellent levels of stereochemical inversion (99 %→≥95 % ee). In a practical one-pot procedure, the primary formed chlorides can be further transformed into amines, azides, ethers, sulfides, and nitriles. The value of the method was demonstrated in straightforward syntheses of the drugs rac-Clopidogrel and S-Fendiline.
- Huy, Peter H.,Motsch, Sebastian,Kappler, Sarah M.
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p. 10145 - 10149
(2016/08/16)
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- METHOD OF CONVERTING ALCOHOL TO HALIDE
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The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
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Page/Page column 50; 132; 134; 158
(2017/01/02)
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- Continuous-Flow Multistep Synthesis of Cinnarizine, Cyclizine, and a Buclizine Derivative from Bulk Alcohols
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Cinnarizine, cyclizine, buclizine, and meclizine belong to a family of antihistamines that resemble each other in terms of a 1-diphenylmethylpiperazine moiety. We present the development of a four-step continuous process to generate the final antihistamines from bulk alcohols as the starting compounds. HCl is used to synthesize the intermediate chlorides in a short reaction time and excellent yields. This methodology offers an excellent way to synthesize intermediates to be used in drug synthesis. Inline separation allows the collection of pure products and their immediate consumption in the following steps. Overall isolated yields for cinnarizine, cyclizine, and a buclizine derivative are 82, 94, and 87 %, respectively. The total residence time for the four steps is 90 min with a productivity of 2 mmol h-1. The incredible bulk: Bulk alcohols are converted continuously into chlorides using HCl in a microflow. A reaction network that consists of four steps and two inline separations leads to the continuous preparation of cinnarizine, cyclizine, and a buclizine derivative with yields of 82, 94, and 87 %, respectively. The total residence time for the four steps is 90 min with a productivity of 2 mmol h-1.
- Borukhova, Svetlana,Nol, Timothy,Hessel, Volker
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- Halogen Exchange Reaction of Aliphatic Fluorine Compounds with Organic Halides as Halogen Source
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The halogen exchange reaction of aliphatic fluorine compounds with organic halides as the halogen source was achieved. Treatment of alkyl fluorides (primary, secondary, or tertiary fluorides) with a catalytic amount of titanocene dihalides, trialkyl aluminum, and polyhalomethanes (chloro or bromo methanes) as the halogen source gave the corresponding alkyl halides in excellent yields under mild conditions. In the case of a fluorine/iodine exchange, no titanocene catalyst is needed. Only C-F bonds are selectively activated under these conditions, whereas alkyl chlorides, bromides, and iodides are tolerant to these reactions.
- Mizukami, Yuki,Song, Zhiyi,Takahashi, Tamotsu
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p. 5942 - 5945
(2016/01/09)
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- SYNTHETIC METHOD FOR THE PREPARATION OF 1, 2-BENZISOTHIAZOLIN-3-ONE
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The present invention relates to a method for producing a 1,2-benzisothiazolin-3-one compound (I) by reacting a 2-halobenzonitrile compound (II) with a thiol compound (III) to form an intermediate (IV) and subsequently reacting the intermediate (IV) with a halogenation agent in the presence of water to form a reaction mixture (RM), comprising the 1,2-benzisothiazolin-3-one compound (I) and a halide compound (V).
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- Synthetic method for the preparation of 1,2-Benzisothiazolin-3-one
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The present invention relates to a method for producing a 1,2-benzisothiazolin-3-one compound (I) by reacting a 2-halobenzonitrile compound (II) with a thiol compound (III) to form an intermediate (IV) and subsequently reacting the intermediate (IV) with a halogenation agent in the presence of water to form a reaction mixture (RM), comprising the 1,2-benzisothiazolin-3-one compound (I) and a halide compound (V). R3-SH (III), R3_X1(V),
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Paragraph 0163; 0166; 0169
(2015/12/18)
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- The inner leg and the outer leg side joint and a knee brace set of side joint
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A knee brace capable of correction only in a required angle range and of reproducing a normal screw-home movement in a knee joint of a knee osteoarthritis patient having outer and inner leg joints including first and second couplings coupled at coupling portions. The coupling portion includes a cam groove, a long groove, a rotation fulcrum shaft, and a cam shaft. When flexing the knee, the rotation fulcrum shaft and the cam shaft slide in the long groove and the cam groove and the second coupling rotates around the coupling portion with respect to the first coupling to flex the leg joints, and when extending the leg joints, the rotation fulcrum shaft and the cam shaft slide in the long groove and the cam groove to move the second coupling on the outer leg side upward and rearward and the second coupling on the inner leg side downward and forward.
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- 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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p. 231 - 236
(2013/02/23)
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- Chlorination of hydrocarbons with CCl4 catalyzed by complexes of Mn, Mo, V, Fe
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Catalytic chlorination of alkanes, cycloalkanes, and adamantane utilizing tetrachloromethane as the source of chlorine and applying catalysts containing manganese, molybdenum, vanadium, and iron activated with nitrile ligands, alcohols, and water was fulfilled. The optimum ratios of catalysts and reagents and the best reaction conditions were found for selective synthesis of chlorine-substituted hydrocarbons derivatives. Pleiades Publishing, Ltd., 2013.
- Khusnutdinov,Shchadneva,Bayguzina,Oshnyakova,Mayakova,Dzhemilev
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p. 1557 - 1566
(2014/02/14)
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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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- An efficient method for chlorination of alcohols using PPh3/Cl3CCONH2
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A new and convenient method for the chlorination of alcohols utilizing PPh3/Cl3CCONH2 is addressed. Various alcohols could smoothly be converted into their corresponding alkyl chlorides in high yield under mild conditions with short reaction times. A mechanism is disclosed with the evidence of inversion of configuration of the analogous alkyl chloride derived from R-(-)-2-octanol.
- Pluempanupat, Wanchai,Chavasiri, Warinthorn
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p. 6821 - 6823
(2007/10/03)
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- A mild, phosphine-free method for the conversion of alcohols into halides (Cl, Br, I) via the corresponding O-alkyl isoureas
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A novel procedure for the conversion of primary and secondary alcohols into the corresponding alkyl chlorides, bromides and iodides is described. The transformation is high-yielding in the case of chlorides and bromides, tolerates a range of functional groups, and does not rely on the use of phosphines.
- Li, Zhengning,Crosignani, Stefano,Linclau, Bruno
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p. 8143 - 8147
(2007/10/03)
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- A facile conversion of thiols to alkyl halides by triphenylphosphine/N-halosuccinimides
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Thiols are efficiently converted to alkyl halides in high to excellent yields when treated with triphenylphosphin/N-halosuccinimide (halogen: Br,Cl, and I) in dichloromethane at room temperature.
- Iranpoor,Firouzabadi,Aghapour
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p. 1176 - 1178
(2007/10/03)
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- Syntheses of long-chain quaternary ammonium salts from fatty alcohols by microwave irradiation
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The phase-transfer catalysts, long-chain quaternary ammonium salts, were rapidly synthesized from fatty alcohols by the reactions with hydrogen halides in the presence of trialkyl amines under microwave irradiation. The catalysts could be widely applied in a variety of quick and new organic reactions, whether by conventional heating or under microwave irradiation. The reaction efficiencies under microwave irradiation were higher than those obtained with conventional heating.
- Jiang,Hu,Pang,Yuan
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p. 847 - 850
(2007/10/03)
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- A Convenient Conversion of Primary Amines into the Corresponding Halides Radical Promoted Halodeamination via N-Substituted-N-Tosylhydrazines
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Treatment of 1-substituted-1-tosylhydrazines with 2 equivalents of NCS or NBS in dry THF in presence of light affords the corresponding alkyl halides in good yields.This reaction presumably involves the initial formation of a stabilized hydrazyl radical which is halogenated in a radical chain process.Elimination of p-toluenesulfinic acid and extrusion of nitrogen leads to the corresponding alkyl halide.This route provides an improved method for halodeamination under neutral reaction conditions.
- Collazo, Luis R.,Guziec, Frank S.,Hu, Wei-Xiao Jr.,Pankayatselvan, Ratnadevi
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p. 7911 - 7914
(2007/10/02)
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- Organic Synthesis in Micellar Media. Oxidation of Alcohols and Their Conversion into Alkyl Chlorides
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The use of micelles was investigated for various organic reactions: oxidation of alcohols with sodium hypochlorite in micelles, oxidation of alcohols with hexadecyltrimethylammonium chromate as micelle, and conversion of primary alcohols to 1-chloroalkanes by aqueous hydrogen chloride in the presence of micelles.In all cases, product isolation was simple and satisfactory yields were obtained.
- Jursic, Branko
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p. 868 - 871
(2007/10/02)
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- A Functionalized Alkyldiphenylphosphine as an Efficient and Mild Reagent in CCl4-Promoted Substitution Reactions: Kinetics and Mechanism of the Reaction in CHCl3
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(Pyrid-2-ylethyl)diphenylphosphine can be used at 35-45 deg C in carbon tetrachloride-chloroform to give high yields of primary and secondary alkyl chlorides from the corresponding alcohols. The isolation of products is simplified by removal of the phosphorus-containing products by extraction into a dilute aqueous acid solution.The complex reaction was studied by 31P NMR.The rate constants based on the decay of phosphine are reported.The rapid conversion of alcohols proceeds equally via chlorination by CCl3 (path A) and by Cl (path B).The rates of formation and decay of an isobutoxyphosphonium intermediate, Cl, have been measured with 31P NMR.
- Toto, Susan D.,Doi, Joyce Takahashi
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p. 4999 - 5003
(2007/10/02)
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- CIS 1,2-FUNCTIONALIZATION OF CYCLOHEXANE USING SELENIUM INTERMEDIATES
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The trans 1,2-phenylseleno acetate, acetamide, alcohol and nitrile of cyclohexane may be oxidized at selenium by halogens and the phenylseleno moiety displaced by halide to give high yields of 1,2 halide-containing products with cis geometry.
- Morella, Angelo M.,Ward, A. David
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p. 2899 - 2900
(2007/10/02)
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- PREPARATION OF ALKYL HALIDES VIA ORGANOTELLURIUMS
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The conversion of phenyltelluroalkanes to haloalkanes was studied in connection with the homologation of alkyl halides.Similar reactions of 1,1-bis(phenyltelluro)alkanes provided a new synthetic method of aldehydes.
- Chikamatsu, Kiyofumi,Otsubo, Tetsuo,Ogura, Fumio,Yamaguchi, Hachiro
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p. 1081 - 1084
(2007/10/02)
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- Process for preparing dimethylaminomethylenebis(phosphonic acid)
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Dimethylaminomethylenebis(phosphonic acid) is prepared by reacting dimethylformamide with phosphorous trichloride and treating the reaction mixture with alcohols or glycols and water. The phosphonic acid is combined with water soluble carboxylic acid polymers for use as a corrosion and scale inhibitor in aqueous systems. These compositions may also be combined with phosphorous acid and water soluble zinc salts.
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- 1-[2-(1-Adamantyl)-2-(R-thio)ethyl]imidazoles and 1-[2-(1-adamantyl)-2-(R-oxy)ethyl]imidazoles
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Compounds of the formula STR1 wherein R is alkyl, cycloalkyl, cycloalkyl lower alkyl, phenyl or phenyl lower alkyl, said phenyl and phenyl lower alkyl optionally substituted on the phenyl ring with one or more substituents independently selected from the group consisting of halo, lower alkyl and trifluoromethyl; and X is oxygen or sulfur with the proviso that X is not oxygen when R is phenyl or substituted phenyl; and the antimicrobial acid addition salts thereof are useful as antifungal, antibacterial and antiprotozoal agents.
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- 2,4,6-Trialkyl-3-hydroxyphenylalkane phosphonates and phosphinates
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The compounds are trialkylsubstituted hydroxyphenylalkanephosphinates and phosphonates having the formula SPC1 Wherein R, R1 and R2 are independently lower alkyl or cycloalkyl groups, R3 is alkyl, alkyl substituted with one halogen atom, phenyl, phenyl substituted with alkyl groups, alkoxy, alkoxy substituted with one halogen groups, phenoxy, phenoxy substituted with alkyl groups, alkylthioethoxy, alkyloxalkylenoxy, R4 is alkyl, alkyll substituted with one halogen atom, cycloalkyl, phenyl, phenyl substituted with alkyl groups, alkylthioethyl, thiobisalkylene, alkylene, polyvalent cyclic or acyclic hydrocarbon radical, A is lower alkylene and n is 1 to 4. These compounds are usually prepared by reacting the trialkylsubstituted hydroxybenzyl or hydroxyphenylalkyl halide with the appropriate trialkyl or triaryl phosphite or appropriate substituted phosphinite. The compounds are useful as stabilizers of organic materials subject to oxidative, thermal and UV light deterioration.
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