- Selective Pd-catalyzed hydrogenation of 3,3-diphenylallyl alcohol: Efficient synthesis of 3,3-diarylpropylamine drugs diisopromine and feniprane
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The Pd-catalyzed selective hydrogenation of C[dbnd]C double bond in (3,3-diphenylallyl)diisopropylamine or 3,3-diphenylallyl alcohol was evaluated using different catalytic systems [Pd/C, Pd(OAc)2/ionic liquid, isolated Pd(0) nanoparticles]. For the (3,3-diphenylallyl)diisopropylamine, hydrogenolysis is preferred over hydrogenation, and only moderate selectivities were obtained for the desired product. However, complete conversion and 100% selectivity were obtained for the hydrogenation of 3,3-diphenylallyl alcohol using isolated Pd(0) nanoparticles under mild condition. This successful strategy enabled the effective synthesis of diisopromine and feniprane drugs and opens new possibilities for the preparation of other biologically active compounds.
- Claudino, Thiago S.,Scholten, Jackson D.,Monteiro, Adriano L.
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Read Online
- The Participation Effect of Halogen Atoms in Stereospecific Friedel-Crafts Alkylations
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The Friedel-Crafts alkylation of benzene with optically active 1,2-, 1,3-, 1,4-, and 1,5-dihalogenoalkanes gave the corresponding primary phenylalkyl halides with a stereospecificity which depended primarily on the type of terminal halogen or the variation in carbon chain length.
- Masuda, Shinji,Segi, Masahito,Nakajima, Tadashi,Suga, Sohei
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Read Online
- Reductive activation and hydrofunctionalization of olefins by multiphoton tandem photoredox catalysis
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The conversion of olefin feedstocks to architecturally complex alkanes represents an important strategy in the expedient generation of valuable molecules for the chemical and life sciences. Synthetic approaches are reliant on the electrophilic activation of unactivated olefins, necessitating functionalization with nucleophiles. However, the reductive functionalization of unactivated and less activated olefins with electrophiles remains an ongoing challenge in synthetic chemistry. Here, we report the nucleophilic activation of inert styrenes through a photoinduced direct single electron reduction to the corresponding nucleophilic radical anion. Central to this approach is the multiphoton tandem photoredox cycle of the iridium photocatalyst [Ir(ppy)2(dtbbpy)] PF6, which triggers in situ formation of a high-energy photoreductant that selectively reduces styrene olefinic π bonds to radical anions without stoichiometric reductants or dissolving metals. This mild strategy enables the chemoselective reduction and hydrofunctionalization of styrenes to furnish valuable alkane and tertiary alcohol derivatives. Mechanistic studies support the formation of a styrene olefinic radical anion intermediate and a Birch-type reduction involving two sequential single electron transfers. Overall, this complementary mode of olefin activation achieves the hydrofunctionalization of less activated alkenes with electrophiles, adding value to abundant olefins as valuable building blocks in modern synthetic protocols.
- Czyz, Milena L.,Taylor, Mitchell S.,Horngren, Tyra H.,Polyzos, Anastasios
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p. 5472 - 5480
(2021/06/01)
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- Indium Tribromide-Catalysed Transfer-Hydrogenation: Expanding the Scope of the Hydrogenation and of the Regiodivergent DH or HD Addition to Alkenes
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The transfer-hydrogenation as well as the regioselective and regiodivergent addition of H?D from regiospecific deuterated dihydroaromatic compounds to a variety of 1,1-di- and trisubstituted alkenes was realised with InBr3 in dichloro(m)ethane. In comparison with the previously reported BF3?Et2O-catalysed process, electron-deficient aryl-substituents can be applied reliably and thereby several restrictions could be lifted, and new types of substrates could be transformed successfully in hydrodeuterogenation as well as deuterohydrogenation transfer-hydrogenation reactions.
- Li, Luomo,Hilt, Gerhard
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supporting information
p. 11221 - 11225
(2021/06/25)
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- Photocatalytic Hydromethylation and Hydroalkylation of Olefins Enabled by Titanium Dioxide Mediated Decarboxylation
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A versatile method for the hydromethylation and hydroalkylation of alkenes at room temperature is achieved by using the photooxidative redox capacity of the valence band of anatase titanium dioxide (TiO2). Mechanistic studies support a radical-based mechanism involving the photoexcitation of TiO2 with 390 nm light in the presence of acetic acid and other carboxylic acids to generate methyl and alkyl radicals, respectively, without the need for stoichiometric base. This protocol is accepting of a broad scope of alkene and carboxylic acids, including challenging ones that produce highly reactive primary alkyl radicals and those containing functional groups that are susceptible to nucleophilic substitution such as alkyl halides. This methodology highlights the utility of using heterogeneous semiconductor photocatalysts such as TiO2 for promoting challenging organic syntheses that rely on highly reactive intermediates.
- Zhu, Qilei,Nocera, Daniel G.
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supporting information
p. 17913 - 17918
(2020/12/04)
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- Substitution of Secondary Benzylic Phosphates with Diarylmethyl Anions
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Substitution of diethyl and diphenyl benzylic phosphates, Alk-CH(Ar1)OP(O)(OR)2 (R = Et, Ph; Alk = Me, Et, i-Pr; Ar1 = aryl), with the anions derived from Ar2CH2 (Ph2CH2,9H-xanthene and fluorene) and n-BuLi at –15 °C was studied. For phosphates with Me as an Alk, diethyl phosphates produced Me-CH(Ar1)CH(Ar2)2 (Ar1 = 4-halo-, 4-CN, 4-Me-, 2-Me, 2-Br-, 3-MeO-phenyl and 2-naphthyl). However, an unwanted substitution at the Et group competed with phosphates of Alk = Et- and i-Pr. Fortunately, the corresponding diphenyl phosphates cleanly underwent the desired substitution. Two enantioenriched phosphates, MeCH(Ph)OP(O)(OEt)2 and EtCH(Ph)OP(O)(OPh)2, proceeded with complete inversion of the stereochemistry.
- Shinohara, Riku,Kawashima, Hidehisa,Ogawa, Narihito,Kobayashi, Yuichi
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p. 2717 - 2725
(2019/04/04)
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- SN2 Reaction of Diarylmethyl Anions at Secondary Alkyl and Cycloalkyl Carbons
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The substitution reaction of the diethyl allylic and propargylic phosphates with Ar2CH anions was applied to sec-alkyl phosphates to compare reactivity and stereoselectivity. However, the substitution took place on the ethyl carbon of the diethyl phosphate group. We then found that the diphenyl phosphate leaving group ((PhO)2PO2) was suited for the substitution at the sec-alkyl carbon. Enantioenriched diphenyl sec-alkyl phosphates with different substituents (Me, Et, iPr) on the vicinal position underwent the substitution reaction with almost complete inversion (>99% enantiospecificity). The substitution reactions of cyclohexyl phosphates possessing cis or trans substituents (Me and/or tBu) at the C4, C3, and C2 positions of the cyclohexane ring were also studied to observe the difference in reactivity among the cis and trans isomers. A transition-state model with the phosphate leaving group ((PhO)2PO2) in the axial position was proposed to explain the difference. This model was supported by computational calculation of the virtual substitution reaction of the structurally simpler “dimethyl” cyclohexyl phosphates (leaving group = (MeO)2PO2) with MeLi. Furthermore, the calculation unexpectedly indicated higher propensity of (PhO)2PO2 as a leaving reactivity than alkyl phosphate groups such as (MeO)2PO2 and (iPrO)2PO2.
- Shinohara, Riku,Ogawa, Narihito,Kawashima, Hidehisa,Wada, Kyohei,Saito, Shun,Yamazaki, Takashi,Kobayashi, Yuichi
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p. 1461 - 1478
(2019/01/25)
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- Photochemical Nickel-Catalyzed Reductive Migratory Cross-Coupling of Alkyl Bromides with Aryl Bromides
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A novel method to access 1,1-diarylalkanes from readily available, nonactivated alkyl bromides and aryl bromides via visible-light-driven nickel and iridium dual catalysis, wherein diisopropylamine (iPr2NH) is used as the terminal stoichiometric reductant, is reported. Both primary and secondary alkyl bromides can be successfully transformed into the migratory benzylic arylation products with good selectivity. Additionally, this method showcases tolerance toward a wide array of functional groups and the presence of bases.
- Peng, Long,Li, Zheqi,Yin, Guoyin
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supporting information
p. 1880 - 1883
(2018/04/16)
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- Ligand-Controlled Nickel-Catalyzed Reductive Relay Cross-Coupling of Alkyl Bromides and Aryl Bromides
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1,1-Diarylalkanes are important structural frameworks which are widespread in biologically active molecules. Herein, we report a reductive relay cross-coupling of alkyl bromides with aryl bromides by nickel catalysis with a simple nitrogen-containing ligand. This method selectively affords 1,1-diarylalkane derivatives with good to excellent yields and regioselectivity.
- Peng, Long,Li, Yuqiang,Li, Yangyang,Wang, Wang,Pang, Hailiang,Yin, Guoyin
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p. 310 - 313
(2018/01/17)
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- Reductive cross-coupling of conjugated arylalkenes and aryl bromides with hydrosilanes by cooperative palladium/copper catalysis
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A method for the reductive cross-coupling of conjugated arylalkenes and aryl bromides with hydrosilanes by cooperative palladium/copper catalysis was developed, thus resulting in the highly regioselective formation of various 1,1-diarylalkanes, including a biologically active molecule. Under the applied reaction conditions, high levels of functional-group tolerance were observed, and the reductive cross-coupling of internal alkynes with aryl bromides afforded trisubstituted alkenes. Forming a Co-op: A method for the reductive cross-coupling of conjugated arylalkenes or internal alkynes and aryl bromides with hydrosilanes using cooperative palladium/copper catalysis was developed. The resulting 1,1-diarylalkanes and trisubstituted alkenes were isolated with high regio- and stereoselectivity. Under the applied reaction conditions, high levels of functional-group tolerance were observed.
- Semba, Kazuhiko,Ariyama, Kenta,Zheng, Hong,Kameyama, Ryohei,Sakaki, Shigeyoshi,Nakao, Yoshiaki
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supporting information
p. 6275 - 6279
(2016/05/24)
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- Synthesis of diarylmethanes via metal-free reductive cross-coupling of diarylborinic acids with tosyl hydrazones
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This paper describes a practical and efficient procedure that takes advantage of diarylborinic acids as a cost-effective alternative to arylboronic acids for synthesis of diarylmethanes through metal-free reductive cross-coupling with N-tosylhydrazones of aromatic aldehydes and ketones. The procedure tolerates hydroxyl, halide, amine, and allyl functionality, complementary to the transition-metal catalyzed cross-coupling techniques.
- Li, Xijing,Feng, Yuanyuan,Lin, Lin,Zou, Gang
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p. 10991 - 10995
(2013/02/22)
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- Alternative method for alkylation of arylpolyhalomethanes with trialkylborane in the presence of magnesium
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Reduction of benzal halide derivatives and α,α,α,-trichloromethylbenzene by magnesium powder in DMAc affords α-halocarbanions which then react with triethylborane to give alkylated products. After oxidation with H2O2-NaOH, secondary
- Condon, Sylvie,Nédélec, Jean-Yves
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body text
p. 32 - 35
(2010/09/18)
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- Synthesis of functionalized diaryl alkancs from azines
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Substituted diaryl alkanes arc synthesized from bcnzalazines and acctophenone/propiophenone azines via Friedel Craft's reaction with substituted mono- and poly-nuclear aromatic hydrocarbons. Diaryl methanes/ethanes and propanes are obtained by reaction with benzalazine, N,N'-bis (I-phenyl) azine and N, N'-bis (I-propyl) azine, respectively.
- Manih, Rudolf M.,Myrboh, Bekington
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experimental part
p. 146 - 151
(2009/12/01)
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- Polylithiumorganic compounds. Part 29: C,C Bond cleavage of phenyl substituted and strained carbocycles using lithium metal
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The reaction of phenyl substituted cyclopropanes phenylcyclopropane and 1,1-diphenylcyclopropane, phenyl substituted bicyclobutanes 1- phenylbicyclobutane, 1-methyl-3-phenylbicyclobutane, 1-methyl-2,2- diphenylbicyclobutane, as well as phenyl substituted spiropentanes phenylspiropentane and 1,1-diphenylspiropentane with lithium metal or lithium di-t-butylbiphenyl (LiDBB) was investigated. Under suitable reaction conditions and choice of solvent in all cases cleavage of the single bond next to the activating phenyl group was observed. The dilithiumorganic compounds thus obtained are sufficiently stable and can be trapped with electrophiles. Lithium hydride elimination is observed as follow-up reaction only in a few cases. The corresponding anions of the strained ring systems 1-lithio-2,2- diphenylcyclopropane, 1-lithio-3-phenylbicyclobutane, 1-lithio-3-methyl-2,2- diphenylbicyclobutane, and 1-lithio-4-phenylspiropentane, which can be obtained by lithium bromine exchange or by metalation of the unsubstituted carbocycle, do not show any cleavage upon reaction with lithium metal. The reaction of phenyl substituted cyclopropanes, bicyclobutanes as well as spiropentanes with lithium metal with formation of highly reactive dilithiumorganic compounds was investigated. In all cases cleavage of the bond next to the phenyl substituent(s) was observed.
- Maercker, Adalbert,Oeffner, Kristian S.,Girreser, Ulrich
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p. 8245 - 8256
(2007/10/03)
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- Polyethylene glycol mediated reductive decyanation of diphenylacetonitrile moderately enhanced by microwave heating
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An efficient and clean procedure for the preparation of alkyldiphenylmethanes and 4,4-diphenylbutylamines from their corresponding nitriles by using sodium hydroxide-polyethylene glycol reagent system in a domestic microwave oven is described. The products are isolated by simple aqueous work up in excellent yields.
- Bendale,Chowdhury,Khadilkar
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p. 433 - 435
(2007/10/03)
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- Double coordination and activation ability of methylalumoxane (MAO) for hetero functionality: Pivotal role as polymerization cocatalyst
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A new insight in the crucial role of methylalumoxane (MAO) as polymerization cocatalyst has been demonstrated by using typical carbonyl reduction and electrophilic alkylation by comparison with various MAO analogues, (Me2Al)2O, MeAl(OPr(i))2, and Me2AlOPr(i). Furthermore, the high ligand-abstraction ability of MAO for a zirconocene complex is evaluated by the allylzirconation of internal alkyne, where MAO was found to be more satisfactory as cocatalyst than (Me2Al)2O and Me3Al in terms of reactivity.
- Hanawa, Hideo,Abe, Noriko,Maruoka, Keiji
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p. 5365 - 5368
(2007/10/03)
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- Activation conditions play a key role in the activity of zeolite CaY: NMR and product studies of Bronsted acidity
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CaY, activated under different conditions, was characterized with 1H, 31P, and 1H/27A] double resonance MAS NMR. The 1H MAS NMR spectra of CaY, calcined in an oven at 500 °C, shows resonances from H2O (bound to Ca2+ and the zeolite framework), CaOH+, aluminum hydroxides, silanols, and Bronsted acid sites. No evidence for Lewis acidity is observed on adsorption of trimethylphosphine, and an estimate of ≈16 Bronsted acid sites per unit cell is obtained for this sample. CaY activated in an oven at higher temperatures contains less water, but all the other species are still present. In contrast, CaY activated by slow ramping of the temperature under vacuum to 500 or 600 °C shows a much lower concentration of Bronsted acid sites (1/unit cell). Again, no evidence for Lewis acidity was observed. These NMR results have been utilized to understand the very different product distributions that are observed for reactions of 1,1- and 1,2-diarylethylenes in zeolite CaY activated in an oven (in air) and under vacuum. Samples with high concentrations of Bronsted acid sites react stoichiometrically with these sites, yielding diarylalkanes. At low concentrations, the Bronsted acid sites can act catalytically resulting in isomerization reactions.
- Kao, Hsien-Ming,Grey, Clare P.,Pitchumani, Kasi,Lakshminarasimhan,Ramamurthy
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p. 5627 - 5638
(2007/10/03)
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- The reaction of substituted vinylsilanes with lithium metal
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Vinylsilanes are known to react with lithium metal to form either 1,2-dilithioethanes by reduction or 1,4-dilithiobutanes by reductive dimerization. The reaction of the substituted vinylsilanes 3, (Z)-13b, 17b, c, 42b, c, 44, and 51 with lithium has been investigated. Depending on the substituents on the vinylsilane and the solvent employed, several new reaction pathways are observed, which have been proved by independent syntheses of the reactive intermediates (E)-14b, 18d, and 25-27. Thus, besides the known elimination of lithium hydride, either a 1,4-proton shift of 25 to 26 or a Grovenstein-Zimmerman rearrangement of 45 to 47 can occur as follow-up reactions. Furthermore, two different types of dimerization of the silyl-substituted vinyllithium compounds have been identified. Either the vinyllithium compound 18d adds to the starting vinylsilane leading to the monolithiumorganic species 41, or lithium metal catalyzed dimerization to the 1,4-dilithio-2-butene derivative 49 takes place, which is without precedence.
- Maercker, Adalbert,Reider, Kerstin,Girreser, Ulrich
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p. 1455 - 1465
(2007/10/03)
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- A Novel C-C Single-Bond Formation Accompanying C-O Bond Cleavage by Use of a Ketone, an Alkylating Reagent, and a Low-Valent Vanadium Complex in the Presence of a Catalytic Amount of Molecular Oxygen
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A C-C single-bond-forming reaction from ketones with accompanying C-O bond cleavage mediated by a RMgBr or RLi-vanadium(II)-O2 system has been accomplished. Different from conventional reductive coupling reactions of ketones such as the McMurry coupling, the present method forms a C-C single (instead of a double) bond and yields a product that contains components derived from the ketone and the alkylating reagent in a one-pot reaction. Collaboration of both a low-valent vanadium(II) species and a higher-valent vanadium species produced from vanadium(II) and a catalytic amount of O2 effects the abstraction of the oxygen atom from a C-O bond.
- Kataoka, Yasutaka,Akiyama, Hiroaki,Makihira, Isamu,Tani, Kazuhide
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p. 8109 - 8113
(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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- Photoinduced Nucleophilic Addition of Ammonia and Alkylamines to Aryl-Substituted Alkenes in the Presence of p-Dicyanobenzene
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The photoamination of 1,1-diphenylpropene (1a) with ammonia and some primary alkylamines in the presence of p-dicyanobenzene gave the corresponding N-substituted 2-amino-1,1-diphenylpropane (2a-e) along with the formation of 3-methyl-4,4-diphenylbutanenitrile (3a), 1,1-diphenylpropane (4a), 3,3-diphenylpropene (5), and diphenylmethane (6).In the case of 1,1-diphenylethene (1b), N-substituted 1-amino-2,2-diphenylethane (2f-h), 4,4-diphenylbutanenitrile (3b), and 1,1-diphenylethane (4b) were produced.In photoamination with t-butylamine in acetonitrile, 3a and 3b were mainly formed as a consequence of the incorporation of acetonitrile to 1a and 1b.The photoamination of 1-phenyl-3,4-dihydronaphthalene (1c) with isopropylamine or t-butylamine gave cis- and trans-N-substituted 1-phenyl-2-amino-1,2,3,4-tetrahydronaphthalenes (15 and 16) in a ratio of ca. 8:2.The mechanism of photoamination is discussed in terms of a photochemical electron transfer of 1 to p-dicyanobenzene followed by a nucleophilic addition of the amine to the cation radical of 1.
- Yamashita, Toshiaki,Shiomori, Koichiro,Yasuda, Masahide,Kensuke, Shima
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p. 366 - 374
(2007/10/02)
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- Reductive Alkylation and Reduction of Tertiary, Secondary, and Benzylic Alcohols with Trimethyl-, Triethyl-, and Triisopropylboron/Trifluoromethanesulfonic (Triflic) Acid
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Tertiary, secondary, and benzylic alcohols were reductively alkylated and reduced with trimethyl-, triethyl-, and triisopropylboron/trifluoromethanesulfonic (triflic) acid.A postulated mechanism for the reactions is discussed.
- Olah, George A.,Wu, An-hsiang,Farooq, Omar
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p. 2759 - 2761
(2007/10/02)
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- Diisocyanates of the diphenyl methane series and processes for the production thereof
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A diisocyanate corresponding to the general formula: STR1 in which R1, R2 and R3 represent hydrogen or a C2 -C12 alkyl group provided that two of the radicals R1, R2 and R3 represent hydrogen and the third represents an alkyl group containing from 2 to 12 carbon atoms. Mixtures of diisocyanates in which the described diisocyanate is a major substituent are also within the scope of this disclosure. Such compounds and mixtures are made by reacting a nitrobenzyl halide, an unsubstituted benzyl halide or a benzyl alcohol in the presence of a Friedel-Crafts catalyst with an alkylbenzene or a nitroalkylbenzene and then converting the nitro groups to amino groups by hydrogenation or reduction. The thus-produced amino compound is then phosgenated to form the diisocyanate. The compounds and mixtures of the present invention are useful in the production of polyurethane plastics.
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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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- Carbanion Rearrangements by Intramolecular 1,ω Proton Shifts, IV. The Reaction of ω,ω-Diphenylalkyllithium Compounds: Proof for an Intramolecular Transmetallation Reaction by Crossover Experiments Using Isotopic Labelled Starting Material
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3,3-Diphenylpropyllithium (2) and 2-(9-fluorenyl)ethyllithium (43) do not show a 1,3 proton shift but splitt off ethylene.On the other hand 4,4-diphenylbutyllithium (19) in diethyl ether can be forced to rearrange to 1,1-diphenylbutyllithium (18) by the addition of THF.The half reaction time for this 1,4 proton shift was found to be about 4 minutes.Proof for the intramolecular character of this transmetallation reaction was obtained by crossover experiments with specifically deuterated starting material.The 1,5 proton shift with 5,5-diphenylpentyllithium (12) occurs considerably slower than the 1,4 shift with 4,4-diphenylbutyllithium (19).The rearrangement also takes place in pure diethyl ether although with a half reaction time of about 2 days.Only 3-(9-fluorenyl)propyllithium (41) in diethyl ether spontaneously shows rearrangement already at -30 deg C, whereby 9-propyl-9-fluorenyllithium (42) is formed by a 1,4 proton shift.A 1,ω phenyl migration according to Grovenstein-Zimmerman in no case could be observed.
- Maercker, Adalbert,Passlack, Michael
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p. 710 - 723
(2007/10/02)
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- Friedel-Crafts Reactions of Benzene with 1-Phenylpropanols. Effects of CuCl2, Cu2Cl2, and Decalin
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Highly regioselective formation of 1,1-diphenylpropane was observed when copper(I) or (II) chlorides was added to the aluminium chloride-catalyzed reaction of benzene with 1-phenyl-1-propanol.In the reaction with 1-phenyl-2-propanol, the addition of copper salts increased the formation of 1,1-diphenylpropane.The addition of decalin diminished the alkylation reaction to give a reduction product.
- Ichikawa, Katsuhiko,Chano, Keizo,Inoue, Masashi,Sugita, Toshio
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p. 3039 - 3040
(2007/10/02)
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- Hydrogenolysis of Small Cycloalkanes, VII. Selective Hydrogenation of 1,1-Disubstituted Cyclopropane Derivatives
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On hydrogenation of 1,1-disubstituted cyclopropane derivatives 1 hydrogenolysis of the C-2-C-3 bond to yield 2 is promoted by electron releasing groups (R =alkyl, CH2OH, OR).On the other hand the presence of electron attracting substituents (R = CO2R, COR, CN) causes opening of the C-1-C-2 bond and formation of products 3. 1,1-Bis(trifluoromethyl)cyclopropane could not be hydrogenated.
- Groeger, Claus,Musso, Hans,Rossnagel, Ingrid
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p. 3621 - 3628
(2007/10/02)
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