- Direct Synthesis of Indanes via Iron-Catalyzed Dehydrative Coupling/Friedel–Crafts Cyclization of Two Different Alcohols
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We report herein a novel iron-catalyzed cascade dehydrative coupling/Friedel–Crafts cyclization of two different alcohols, providing a variety of indanes, which are ubiquitous substructures found in natural products, pharmaceuticals, and functional materi
- Sai, Masahiro
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supporting information
p. 1102 - 1106
(2019/02/14)
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- Non-corrosive heteropolyacid-based recyclable ionic liquid catalyzed direct dehydrative coupling of alcohols with alcohols or alkenes
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A non-corrosive, recyclable and efficient heterogeneous catalyst based on Keggin-type polyoxometalate, i.e., [NMPH]H3[SiW12O40] was developed for the direct dehydrative coupling of alcohols with alcohols (or alkenes) to synthesize various polysubstituted olefins in good to excellent yields. Furthermore, this reaction could be scaled up and the catalyst could be used for seven runs without significant loss of activity. The kinetic competition experiment shows that the C–H bond cleavage might be involved in the rate-determining step.
- Yang, Guo-Ping,Jiang, Nan,Huang, Xian-Qiang,Yu, Bing,Hu, Chang-Wen
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- Metal-Free Dehydrogenative Diels-Alder Reactions of Prenyl Derivatives with Dienophiles via a Thermal Reversible Process
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An efficient dehydrogenative Diels-Alder reaction of prenyl derivatives with dienophiles has been developed. The reaction exhibits broad substrate scope and provides efficient access to cyclohexene derivatives with good to excellent yields. A reasonable mechanism involving a metal-free thermal reversible process is proposed.
- Xu, Wen-Lei,Zhang, Heng,Hu, Yu-Long,Yang, Hui,Chen, Jie,Zhou, Ling
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supporting information
p. 5774 - 5778
(2018/09/21)
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- Metal-free and recyclable route to synthesize polysubstituted olefins via C-C bond construction from direct dehydrative coupling of alcohols or alkenes with alcohols catalyzed by sulfonic acid-functionalized ionic liquids
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A direct synthesis of polysubstituted olefins via construction of C-C bonds, which involves the direct dehydrative coupling of alcohols or alkenes with alcohols, was realized using a series of alkanesulfonic acid group-functionalized ionic liquids (SO3H-functionlization ILs) without additives. The metal-free and recyclable catalyst system avoided the disposal and neutralization of acidic catalysts after reaction and tolerated a broad range of substrates, including benzylic, allyl, propargylic, aliphatic and aromatic or aliphatic olefins. Additionally, the catalytic system was suitable for a gram-scale preparation. Preliminary mechanistic studies indicated that the C-H bond cleavage in this reaction might be involved in the rate-determining step.
- Han, Feng,Yang, Lei,Li, Zhen,Zhao, Yingwei,Xia, Chungu
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p. 2506 - 2516
(2014/09/17)
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- Enantiospecific, regioselective cross-coupling reactions of secondary allylic boronic esters
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An original syn: The first enantioselective Suzuki-Miyaura cross-coupling of chiral, enantioenriched secondary allylic boronic esters is described (see scheme; DME=dimethoxyethane, Bpin = pinacolboryl, dba = dibenzylideneacetone). Mechanistic studies show that the reactions proceed via γ-selective transmetalation followed by reductive elimination. The reaction provides the first independent confirmation that the transmetalation of boronic esters proceeds via a syn pathway. Copyright
- Chausset-Boissarie, Laetitia,Ghozati, Kazem,Labine, Emily,Chen, Jack L.-Y.,Aggarwal, Varinder K.,Crudden, Cathleen M.
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p. 17698 - 17701
(2014/01/17)
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- A novel efficient method for the synthesis of substituted olefins; Cross coupling of two different alcohols using NaHSO4/SiO2
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Simple and efficient cross coupling of alcohols was developed in the presence of NaHSO4/SiO2 to give the corresponding substituted olefins. Direct coupling of alcohols and alkenes was also achieved to give substituted olefins. NaHSO4/SiO2 could be recycled 7 times without loss of catalytic activity.
- Aoyama, Tadashi,Koda, Shuichi,Takeyoshi, Yuka,Ito, Tetsuhiro,Takido, Toshio,Kodomari, Mitsuo
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p. 6605 - 6607
(2013/07/26)
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- Direct carbon-carbon bond formation from alcohols and active methylenes using NaHSO4/SiO2
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A simple and efficient procedure for carbon-carbon bond formation has been developed starting from alcohols and active methylene-containing compounds using silica gel supported sodium hydrogen sulfate (NaHSO4/SiO 2) under mild conditions. NaHSO4/SiO2 can be reused without loss of catalytic activity at least ten times. Georg Thieme Verlag Stuttgart · New York.
- Aoyama, Tadashi,Miyota, Saki,Takido, Toshio,Kodomari, Mitsuo
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experimental part
p. 2971 - 2976
(2012/01/04)
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- Direct coupling of alcohols with alkenylsilanes catalyzed by indium trichloride or bismuth tribromide
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Indium halides or bismuth halides catalyzed the coupling of various alcohols with alkenylsilanes to give the corresponding alkenes stereospecifically without any other activators. The Royal Society of Chemistry 2008.
- Nishimoto, Yoshihiro,Kajioka, Masayuki,Saito, Takahiro,Yasuda, Makoto,Baba, Akio
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supporting information; experimental part
p. 6396 - 6398
(2009/04/13)
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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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- Unexpected oxadi-π-methane rearrangement of β,γ-unsaturated aldehydes
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The oxadi-π-methane rearrangement (ODPM) is considered to represent the normal photochemical behavior of β,γ-unsaturated ketones in the triplet excited π,π* state. However, the usual photoreactivity reported for the majority of β,γ-unsaturated aldehydes i
- Armesto, Diego,Ortiz, Maria J.,Romano, Santiago,Agarrabeitia, Antonia R.,Gallego, Mar G.,Ramos, Ana
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p. 1459 - 1466
(2007/10/03)
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- Photochemistry of the Carbon-Nitrogen Double Bond. Part 2. An Investigation of the 3-Methylenepropan-1-imine and 3-Oxopropan-1-imine Chromophores
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The synthesis of the non-conjugated imino compounds N-methoxy-2,2,4-trimethyl-1-phenylpent-3-en-1-imine (8), N-methoxy-2,2-dimethyl-4,4-diphenylbut-3-en-1-imine (9), 2-(1,1-dimethyl-3,3-diphenylprop-2-enyl)-4,4-dimethyl-4,5-dihydro-oxazole (10), and 2-ben
- Pratt, Albert C.,Abdul-Majid, Qais
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p. 359 - 364
(2007/10/02)
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- PHOTOCHEMISTRY OF β,γ-UNSATURATED KETONES - V ; THE DIRECT IRRADIATION OF SOME γ-PHENYL β;γ-ENONES
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The photochemistry of some members of the two series of γ-phenyl substituted acyclic β,γ-unsaturated ketones 1 and 2 upon direct irradiation with λ 310 nm has been investigated, viz 1c-1h and 2b+2c.The alkyl substituted (E)-5-phenyl-4-penten-2-ones 1c-1h yield the corresponding 1,3-acyl shift products and (Z)-isomers, and 1g and 1h in addition two decarbonylated products. 2b only yields the (Z)-isomer and some benzaldehyde, but 2c yields the 1,3-acyl shift product, the ODPM product, three hydrocarbons formed by disproportionation of the allyl radical, and some benzaldehyde.The β-phenyl β,γ-UK 3a proved to be photostable.The 1,3-acyl shift products of 1c-1h result mainly from the singlet excited state in a cage radical process.The exclusive formation of the (E)-configuration of the 1,3-acyl shift product is explained in terms of conformational preference of the intermediate allyl radical.It is proposed that the formation of the (Z)-isomer proceeds from 1T(?-?*) which is populated according to .Evidence is presented which supports the proposed mechanism.The β,γ-UK 2b containing a benzoyl moiety leads to a higher degree of (E)-(Z) isomerization than the corresponding 1d which has an acetyl moiety.The triplet energies of (E)- and (Z)-1h are 56 and ca 70 kcal/mol respectively.
- Weerdt, Anton J. A. Van Der,Cerfontain, Hans
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p. 2121 - 2130
(2007/10/02)
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