- Recyclable and reusable PdCl2(PPh3)2/PEG-400/H2O system for the hydrophenylation of alkynes with sodium tetraphenylborate
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A stable and efficient PdCl2(PPh3)2/PEG-400/H2O catalytic system for the hydrophenylation reaction of alkynes has been developed. In the presence of 3 mol% PdCl2(PPh3)2 and 2 equiv. of HOAc, the hydrophenylation of both terminal and internal alkynes with sodium tetraphenylborate proceeded smoothly in a mixture of PEG-400 and water at room temperature or 50 °C to afford a variety of phenyl-substituted alkenes in moderate to high yields. The isolation of the products was easily performed by extraction with petroleum ether, and the PdCl2(PPh3)2/PEG-400/H2O system could be readily recycled and reused six times without apparent loss of catalytic activity.
- Liu, Rong,Zhang, Tingli,Huang, Bin,Cai, Mingzhong
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p. 172 - 178
(2020/07/04)
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- Bimolecular vinylation of arenes by vinyl cations
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Styrene derivatives can be easily synthesized from vinyl triflates and arenes under mild reaction conditions, using [Li][Al(OC(CF3)3)4] as a catalyst and LiHMDS as a base. This transformation is likely to involve a vinyl cation intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process. This journal is
- Bour, Christophe,Gandon, Vincent,Li, Zhilong
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supporting information
p. 6507 - 6510
(2020/07/02)
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- A Highly Reduced Ni-Li-Olefin Complex for Catalytic Kumada-Corriu Cross-Couplings
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The catalytic activity of a highly reduced Ni catalyst in the context of a Kumada-Corriu cross-coupling has been studied. This nickel complex is characterized by its high electron density, stabilized by simple olefin ligands in combination with two Li ions. Landmark reactivity has been found with this precatalyst which operates at cryogenic temperatures, thus allowing the presence of sensitive functionalities. Structural elucidation of oxidative addition intermediates and their reactivity suggest highly reduced species being operative in the C-C bond forming event.
- Nattmann, Lukas,Lutz, Sigrid,Ortsack, Pascal,Goddard, Richard,Cornella, Josep
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supporting information
p. 13628 - 13633
(2018/10/24)
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- Conjugated Microporous Polymer as Heterogeneous Ligand for Highly Selective Oxidative Heck Reaction
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A series of pyridine-type ligands containing C C bonds were designed and synthesized for selective oxidative Heck reaction. These ligands were utilized as functional units and integrated into the skeleton of conjugated microporous polymers. 6,6′-diiodo-2,2′-bipyridine and 1,3,5-triethynylbenzene were polycondensed via Sonogashira cross-coupling strategy to afford CMP-1 material. The resultant CMP-1 was used as a heterogeneous catalytic ligand for the PdII-catalyzed oxidative Heck reaction with high linear selectivity. The linear selectivity of CMP-1 is about 30 times higher than that of bipyridine-based monomer ligand. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts in controlling the regioselectivity in organic reactions.
- Zhou, Yun-Bing,Wang, Yu-Qing,Ning, Li-Chao,Ding, Zong-Cang,Wang, Wen-Long,Ding, Cheng-Ke,Li, Ren-Hao,Chen, Jun-Jia,Lu, Xin,Ding, Yun-Jie,Zhan, Zhuang-Ping
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supporting information
p. 3966 - 3969
(2017/03/27)
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- Development of an air-stable, broadly applicable nickel source for nickel-catalyzed cross-coupling
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The synthesis of NiCl(o-tolyl)(TMEDA) (3; TMEDA = tetramethylethylenediamine) and its application in coupling reactions is described. In combination with a suitable ligand, precatalyst 3 was applied to a wide range of transformations, such as Suzuki, amination, Kumada, Negishi, Heck, borylation, and reductive coupling. Yields of products obtained with 3 are equal or superior to those obtained with common Ni sources such as Ni(cod)2 (1) and NiCl2(dme) (2). Importantly, and unlike 1, complex 3 is stable for months in air as a solid, which eliminates the need for a glovebox and greatly facilitates the reaction setup. Thus, complex 3 is the first highly versatile Ni source that combines the broad applicability of 1 with the air stability of 2.
- Magano, Javier,Monfette, Sebastien
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p. 3120 - 3123
(2015/05/20)
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- Nickel-catalyzed Mizoroki-Heck reaction of aryl sulfonates and chlorides with electronically unbiased terminal olefins: High selectivity for branched products
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Achieving high selectivity in the Heck reaction of electronically unbiased alkenes has been a longstanding challenge. Using a nickel-catalyzed cationic Heck reaction, we were able to achieve excellent selectivity for branched products (≥19:1 in all cases) over a wide range of aryl electrophiles and aliphatic olefins. A bidentate ligand with a suitable bite angle and steric profile was key to obtaining high branched/linear selectivity, whereas the appropriate base suppressed alkene isomerization of the product. Although aryl triflates are traditionally used to access the cationic Heck pathway, we have shown that, by using triethylsilyl trifluoromethanesulfonate, we can effect a counterion exchange of the catalytic nickel complex, such that cheaper and more stable aryl chlorides, mesylates, tosylates, and sulfamates can be used to yield the same branched products with high selectivity. Branching out: A Ni-catalyzed Heck reaction for the preparation of 1,1-disubstituted alkenes is presented. High selectivity for the branched products is achieved with electronically unbiased aliphatic terminal olefins. Regioselectivities remain consistently high (≥19:1) throughout. TESOTf=triethylsilyl trifluoromethanesulfonate. Copyright
- Tasker, Sarah Z.,Gutierrez, Alicia C.,Jamison, Timothy F.
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p. 1858 - 1861
(2014/03/21)
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- Regioselective Heck reaction of aliphatic olefins and aryl halides
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A regioselective Heck reaction of aliphatic olefins and aryl bromides is realized at internal carbons of olefins. Methanol solvent promoted halide ionization from neutral arylpalladium halide complexes via hydrogen bonding, so as to create cationic aryl-Pd species for regioselective olefin insertion.
- Qin, Liena,Hirao, Hajime,Zhou, Jianrong
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supporting information
p. 10236 - 10238
(2013/10/22)
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- Intermolecular mizoroki-heck reaction of aliphatic olefins with high selectivity for substitution at the internal position
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New ligand for old reaction: The title reaction of aryltriflates with aliphatic olefins leads to substitution at the internal position with high selectivity. The ratio of the desired isomer (shown in the scheme) to the sum of all other isomers is generall
- Qin, Liena,Ren, Xinfeng,Lu, Yunpeng,Li, Yongxin,Zhou, Jianrong
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p. 5915 - 5919
(2012/07/30)
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- Cobalt-catalyzed coupling of alkenyl triflates with aryl and alkenyl grignard reagents
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Co(acac)3-PPh3 was found to effectively catalyze the C(sp2)-C(sp2) coupling of Grignard reagents to give alkenyl-arenes and conjugated dienes, utilizing close affinity towards alkenyl triflates. Copyright
- Shirakawa, Eiji,Imazaki, Yusuke,Hayashi, Tamio
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p. 654 - 655
(2008/12/20)
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- Palladium-catalyzed hydrophenylation of alkynes with sodium tetraphenylborate under mild conditions
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(Chemical Equation Presented) In an aqueous solution of acetic acid, PdCl2(PPh3)2 showed high catalytic activity for the hydrophenylation of both terminal and internal alkynes with sodium tetraphenylborate (NaBPh4) under mild conditions, affording phenyl alkenes in moderate to excellent yields.
- Zeng, Hanxiang,Hua, Ruimao
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p. 558 - 562
(2008/09/17)
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- Palladium-tetraphosphine catalysed heck reaction with simple alkenes: Influence of reaction conditions on the migration of the double bond
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The Heck reaction of aryl halides with simple alk-1-enes is a powerful method for the synthesis of (E)-1-arylalk-1-ene derivatives. The major problem of this reaction is the palladium-catalysed migration of the carbon-carbon double bond along the alkyl ch
- Fall, Yacoub,Berthiol, Florian,Doucet, Henri,Santelli, Maurice
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p. 1683 - 1696
(2008/02/08)
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- A new cine-substitution of alkenyl sulfones with aryltitanium reagents catalyzed by rhodium: Mechanistic studies and catalytic asymmetric synthesis of allylarenes
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The reaction of alkenyl sulfones with aryltitanium triisopropoxide (ArTi(OPr-i )3) in the presence of 3 mol % of [Rh(OH)((S)-binap)]2 in THF at 40 °C gave high yield of cine-substitution products. The catalytic cycle was established by deuterium-labeling studies, and it was applied to catalytic asymmetric synthesis of allylarenes which proceeds with over 99% enantioselectivity. Copyright
- Yoshida, Kazuhiro,Hayashi, Tamio
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p. 2872 - 2873
(2007/10/03)
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- Synthesis and Properties of Cationic Organopalladium Complexes. Remarkable Rate Enhancement in Olefin Insertion into the Palladium-Aryl Bond by the Generation of a Cationic Palladium Complex from trans-
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By removing the bromide ligand in trans- (1) by AgBF4 in the presence and absence of pyridine, pyridine-coordinated and solvent-coordinated cationic complexes, trans-BF4 (2) and trans-BF4 (3) have been obtained.These cationic phenylpalladium complexes show much greater reactivities than do the parent neutral complex 1 toward olefins to give phenylated olefins by insertion followed by β-hydrogen elimination processes.Kinetic studies concerning the insertion of methyl acrylate into the phenyl-palladium bond have indicated that the reactions are first order in the phenylpalladium complexes and that addition of pyridine to a system containing 2 and methyl acrylate inhibits the insertion reaction of the olefin.The results suggest that the generation of a cationic arylpalladium complex with a vacant site is important for the olefins to be inserted.
- Kawataka, Futoshi,Shimizu, Isao,Yamamoto, Akio
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p. 654 - 660
(2007/10/02)
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- Palladium-catalyzed cyclization of ω-haloallenes. A new general route to common, medium, and large ring compounds via cyclic carbopalladation
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A series of ω-haloallenes (4-32) as well as related ω-haloalkenes (41-45) were prepared through the application of known procedures. Their cyclization in the presence of a catalytic amount of Cl2Pd(PPh3)2, a base, e.g., K2CO3, and other appropriate reagents was investigated mostly under two sets of conditions (conditions I and II). The results summarized in Table 1 reveal the following: (1) The Pd-catalyzed cyclization reaction of ω-haloallenes gives the desired five- through twelve-membered and twenty-membered ring products in respectable yields. (2) The use of the dilute solution technique and n-Bu4NCl is advantageous in the synthesis of eight-membered and larger rings. (3) Formation of a carbon-carbon bond uniformly takes place at the central carbon of an allene. (4) The corresponding reaction of ω-haloalkenes fails to give eight- and nine-membered rings and displays an intriguing endo - exo cyclization mode vs ring size profile. (5) The eight-membered ring products were exclusively Z, and the eleven-, twelve-, and twenty-membered ring products were E. The stereochemistry of the nine- and ten-membered rings depends on other factors as well. The putative allylpalladium intermediates can be trapped with external nucleophiles, such as malonate esters, organostannanes, phenols, and amines, to give the corresponding derivatives. The results support the oxidative addition - carbopalladation mechanism leading to the formation of allylpalladium intermediates. The results also indicate that the extents of the actual cyclization process itself may be considerably higher than indicated by the yields of the dehydropalladation products and that some undesirable side reactions, such as double bond isomerization, can be circumvented through trapping with nucleophiles.
- Ma, Shengming,Negishi, Ei-Ichi
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p. 6345 - 6354
(2007/10/02)
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- Dialkylborane-catalyzed hydroboration of alkynes with 1,3,2-benzodioxaborole in tetrahydrofuran
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Dialkylborane catalyzed hydroboration of alkynes with an equimolar amount of 1,3,2-benzodioxaborole in tetrahydrofuran efficiently to provide 2-alkenyl-1,3,2-benzodioxaborole under mild reaction conditions.
- Arase,Hoshi,Mijin,Nishi
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p. 1957 - 1962
(2007/10/02)
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- Sodium tetraphenylborate as a phenylating reagent in the palladium-catalyzed phenylation of alkenes and acid chlorides
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Sodium tetraphenylborate (NaBPh4) reacts with terminal alkenes in acetic acid at 25 deg C in the presence of a catalytic amount of palladium(II) acetate together with silver acetate as a re-oxidant to give the corresponding phenylated alkenes in 22-87percent yield.It also reacts with acid chlorides in tetrahydrofuran (THF) at 25 deg C in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) to give the corresponding phenyl ketones in 51-100percent yield.Carbonylation of the borate with 1-30 atm carbon monoxide (CO) in methanol at 25 deg C in the presence of palladium(II) acetate or sodium chloropalladate (Na2PdCl4) affords a low yield (9-30percent) of benzophenone and methyl benzoate, a higher pressure favoring the formation of the latter.
- Cho, Chan Sik,Itotani, Koichi,Uemura, Sakae
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p. 253 - 259
(2007/10/02)
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- One-pot conversion of terminal alkynes into gem-disubstituted-alkenes
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A one-pot reaction of terminal alkynes with in situ generated hydrogen iodide and organozinc compounds in the presence of Pd(PPh3)4 provided a simple and useful method for the preparation of gem-disubstituted-alkenes.
- Luo, Fen-Tair,Fwu, Shiang-Long,Huang, Wen-Shu
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p. 6839 - 6840
(2007/10/02)
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- A Convenient Synthesis of Some (1-Alkylethenyl)arenes and Bis(1-alkylethenyl)arenes
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The title compounds may be prepared in good yields and high isomeric purities (98 + percent) by reaction of 1-alkylethenylmagnesium bromides with bromo- or dibromoarenes, respectively).An improved synthesis of 2,6-dibromonaphthalene and synthesis of 4,9-dibromopyrene are also described.
- Blatter, Karsten,Schlueter, Arnulf-Dieter
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p. 356 - 359
(2007/10/02)
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- Stereospecific Arylation of Alkenylsilanes with Arylpalladium Acetates
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Alkenyltrimethylsilanes ((E)- and (Z)-RCH=CHSiMe3: R = H, Ph, n-C6H13 and CH3OCH2) stereospecifically reacted at 40 deg C or room temperature with in situ generated phenylpalladium acetate to produce R(Ph)C=CSiMe3 and RCH=C(Ph)SiMe3 with inversion of their geometry.The arylation of CH2=CHSiMe3 with arylpalladium acetates gave (E)-ArCH=CHSiMe3 (Ar = XPH; X = H, 4-Me, 4-MeO, 4-Br, 4-I, 4-EtOCO, and 4-NO2) in good yields.
- Ikenaga, Kazutoshi,Kikukawa, Kiyoshi,Matsuda, Tsutomu
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p. 1276 - 1280
(2007/10/02)
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- Reaction of Diazonium Salts with Transition Metals. Part 11. Palladium-catalyzed Aryldesilylation of Alkenylsilanes by Arenediazonium Salts
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Under palladium(0) catalysis, both (E)- and (Z)-RCH=CHSiMe3(R=Rh, 4-MeC6H4, 4-NO2C6H4, n-C6H13, and MeOCH2) were easily aryldesilylated by ArN2X(Ar=Ph, 4-MeC6H4, 4-BrC6H4 and 4-NO2C6H4; X=BF4, PF6, and Cl) to give (E)-RCH=CHAr and RC(Ar)=CH2 as the main products at 25 deg C in acetonitrile. anti- and syn-1,2-Elimination of Pd(0) and Me3Si from the adducts, threo- and erythro-RCH(PdX)CHSiMe3, generated from ArPdX and (E) and (Z)-RCH=CHSiMe3, respectively, are proposed for the formation of (E)-RCH=CHAr from either isomer of RCH=CHSiMe3.
- Ikenaga, Kazutoshi,Kikukawa, Kiyoshi,Matsuda, Tsutomu
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p. 1959 - 1964
(2007/10/02)
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- Arylation of Olefins by N-Nitroso-N-arylacetamides under Palladium(0) Catalysis: A New Precursor of Arylpalladium Species
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Olefins (styrene, octene-1, cycloheptene, ethyl acrylate, and vinyl acetate) were easily arylated in good yields with N-nitroso-N-arylacetamides (ArN(NO)COCH3: Ar= Ph, 4-MeC6H4, 4-MeOC6H4, 4-ClC6H4, 4-BrC6H4, and 4-IC6H4) under palladium(0) catalysis at 40 deg C within 40 min.
- Kikukawa, Kiyoshi,Naritomi, Masaki,He, Gong-Xin,Wada, Fumio,Matsuda, Tsutomu
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p. 299 - 301
(2007/10/02)
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- STEREOSPECIFIC PHENYLATION OF ALKENYLSILANES WITH PHENYLPALLADIUM ACETATE
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(E)- and (Z)-RCH=CHSiMe3 (R= Ph, n-C6H13, CH3OCH2) reacted stereospecifically with Ph-Pd-OAc to give RCH=C(Ph)SiMe3 and R(Ph)C=CHSiMe3 with inversion of the starting geometry with respect to R and Me3Si groups.
- Kikukawa, Kiyoshi,Ikenaga, Kazutoshi,Wada, Fumio,Matsuda, Tsutomu
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p. 5789 - 5792
(2007/10/02)
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- Palladium(0)-Catalyzed Arylation of Olefins by Arylamines and an Alkyl Nitrite
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Various olefins were arylated by the combination of arylamines and tert-butyl nitrite under palladium catalysis in the presence of acid such as monochloroacetic or acetic.The reaction proceeded in good yields without serious effects from substituents on either the olefinic substrates or the arylamines, including 3-aminopyridine.
- Kikukawa, Kiyoshi,Maemura, Koji,Kiseki, Yasuyuki,Wada, Fumio,Matsuda, Tsutomu,Giam, Choo S.
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p. 4885 - 4888
(2007/10/02)
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- THE PALLADIUM-CATALYZED "HEAD-TO-TAIL" CROSS-COUPLING REACTION OF 1-ALKENYLBORANES WITH PHENYL OR 1-ALKENYL IODIDES. A NOVEL SYNTHESIS OF 2-PHENYL-1-ALKENES OR 2-ALKYL-1,3-ALKADIENES VIA ORGANOBORANES
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The reaction of phenyl or 1-alkenyl iodides with 1-alkenyl-1,3,2-benzodioxaboroles readily obtainable via the hydroboration of 1-alkynes, gives the corresponding "head-to-tail" cross-coupling products, 2-phenyl-1-alkenes or 2-alkyl-1,3-alkadienes, in good yields.The reaction is effectively catalyzed by catalytic amounts of palladium compounds in the presence of triethylamine.
- Miyaura, Norio,Suzuki, Akira
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p. C53 - C56
(2007/10/02)
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- The reaction of iodine with vinyltrialkylborates derived from trialkylboranes and trisylhydrazones of methyl ketones. A new method for synthesis of 1,1-dialkylethenes
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1,1-Dialkylethenes are readily prepared in good yields from vinyltrialkylborates derived from trialkylboranes and trisylhydrazones of methyl ketones by treatment with iodine.
- Avasthi, Kamlakar,Baba, Tsutomu,Suzuki, Akira
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p. 945 - 946
(2007/10/02)
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