The Experts below are selected from a list of 3093 Experts worldwide ranked by ideXlab platform
Kohei Tamao - One of the best experts on this subject based on the ideXlab platform.
-
nickel and palladium catalyzed cross coupling reaction of polyfluorinated arenes and alkenes with Grignard Reagents
Synlett, 2005Co-Authors: Tomoyuki Saeki, Yohei Takashima, Kohei TamaoAbstract:The cross-coupling reaction of fluorobenzene with an aryl Grignard Reagent has been reinvestigated which revealed that the reaction readily proceeds under ordinary conditions using a catalytic amount of NiCl 2 (dppp) even at room temperature. The use of nickel catalysts and Grignard Reagent is essential for the activation of the carbon-fluorine bond. The palladium catalyst is also effective for the 1,2-difluorobenzene and trifluorobenzenes to selectively produce the corresponding mono-coupled products while the nickel-based catalyst system affords a mixture of the mono-coupled product and di- or tri-coupled product.
-
nucleophilic hydroxymethylation by the isopropoxydimethylsilyl methyl Grignard Reagent 1 hydroxymethyl cyclohexanol from cyclohexanone
Organic Syntheses, 2003Co-Authors: Kohei Tamao, Neyoshi Ishida, Yoshihiko Ito, Makoto KumadaAbstract:Nucleophilic hydroxymethylation by the (isopropoxydimethylsilyl)methyl Grignard Reagent: 1-(hydroxymethyl)cyclohexanol from cyclohexanone reactant: (isopropoxydimethylsilyl)methyl chloride (16.67 g, 100 mmol) intermediate: 1-[(isopropoxydimethylsilyl)methyl]cyclohexanol product: 1-(hydroxymethyl)cyclohexanol Keywords: addition, to CO; Grignard and related reactions; metalation reactions, magnesium; oxidation, miscellaneous; replacement reactions, halogen by oxygen; tetrahydrofuran; peroxides, detection; peroxides, disposal
Koichiro Oshima - One of the best experts on this subject based on the ideXlab platform.
-
Silver-catalyzed benzylation and allylation reactions of tertiary and secondary alkyl halides with Grignard Reagents.
Organic Letters, 2008Co-Authors: Hidenori Someya, Hideki Yorimitsu, Hirohisa Ohmiya, Koichiro OshimaAbstract:Treatment of alkyl halides, including tertiary alkyl bromides, with benzylic or allylic Grignard Reagent in the presence of a catalytic amount of silver nitrate in ether yielded the corresponding cross-coupling products in high yields. The coupling reactions of tertiary alkyl halides provide efficient access to quaternary carbon centers.
-
cobalt catalyzed intramolecular heck type reaction of 6 halo 1 hexene derivatives
Organic Letters, 2002Co-Authors: Takuma Fujioka, Tomoaki Nakamura, Hideki Yorimitsu, Koichiro OshimaAbstract:Treatment of 6-iodo-1-hexene derivatives with trimethylsilylmethyl Grignard Reagent in the presence of CoCl2(dppb) in refluxing THF affords Heck-type products, methylenecyclopentanes, in good yields.
-
dialkylation of gem dibromocyclopropanes with trialkylmanganate and manganese ii chloride catalyzed reaction with alkylmagnesium bromide
Tetrahedron Letters, 1996Co-Authors: Rie Inoue, Hiroshi Shinokubo, Koichiro OshimaAbstract:Abstract Treatment of gem-dibromocyclopropanes with trialkylmanganate, derived from manganese(II) chloride and three equivalents of Grignard Reagent or alkyllithium, followed by an addition of electrophiles provided dialkylated cyclopropanes in good yields. It was found the reaction with alkylmagnesium halide proceeded in the presence of a catalytic amount of manganese(II) chloride.
Chris H Senanayake - One of the best experts on this subject based on the ideXlab platform.
-
room temperature palladium catalyzed cross coupling of aryltrimethylammonium triflates with aryl Grignard Reagents
Organic Letters, 2010Co-Authors: Jonathan T Reeves, Daniel R Fandrick, Zhulin Tan, Jinhua J Song, Heewon Lee, Nathan Yee, Chris H SenanayakeAbstract:Aryltrimethylammonium triflates and tetrafluoroborates were found to be highly reactive electrophiles in the Pd-catalyzed cross coupling with aryl Grignard Reagents. The coupling reactions proceed at ambient temperature with a nearly stoichiometric quantity of Grignard Reagent, and diverse functionality is tolerated. Competition experiments established the reactivity of PhNMe3OTf relative to PhCl, PhBr, PhI, and PhOTf.
Nobuaki Kambe - One of the best experts on this subject based on the ideXlab platform.
-
Ni-Catalyzed Dimerization and Hydroperfluoroarylation of 1,3‑Dienes
2018Co-Authors: Takanori Iwasaki, Xin Min, Asuka Fukuoka, Longzhi Zhu, Renhua Qiu, Tao Yang, Masahiro Ehara, Arumugam Sudalai, Nobuaki KambeAbstract:A nickel-catalyzed three-component coupling reaction between perfluoroarenes and two molecules of a 1,3-diene in the presence of an alkyl Grignard Reagent, which acted as a hydride source, provided 3-perfluoroarylated-1,7-octadienes via 1,3-diene dimerization and subsequent perfluoroarylation upon C–F bond cleavage. The reaction proceeded smoothly in a regioselective manner by simply combining NiCl2 and PPh3 as a catalyst and tolerated various functional groups on the perfluoroarenes. When substituted perfluoroarenes were employed, the reaction selectively occurred at the para-position. Mechanistic studies revealed that an anionic Ni complex, generated upon the reaction of Ni(0) with two molecules of a 1,3-diene and an alkyl Grignard Reagent, played an important role in the C–C bond forming step with perfluoroarenes. The C–F bond cleavage was found to be a relatively fast step in the catalytic cycle
-
novel nickel catalyzed coupling reaction of allyl ethers with chlorosilanes alkyl tosylates or alkyl halides promoted by vinyl Grignard Reagent leading to allylsilanes or alkenes
Advanced Synthesis & Catalysis, 2004Co-Authors: Jun Terao, Hiroyasu Watabe, Hiroyuki Watanabe, Nobuaki KambeAbstract:A new method for a carbon-silicon or carbon-carbon bond forming reaction between allyl ethers and chlorosilanes, alkyl tosylates, or alkyl halides giving rise to allylsilanes or alkenes has been developed. This reaction proceeds efficiently at ambient temperature by the combined use of nickel catalysts and a vinyl-Grignard Reagent. A possible reaction pathway involving the formation of allyl-Grignard Reagents via transmetallation of π-allylnickel complexes with the vinyl-Grignard Reagent and subsequent trapping of the thus formed allyl-Grignard Reagents with electrophiles is proposed.
-
formation of 1 4 disilyl 2 butenes from vinyl Grignard Reagent and chlorosilanes catalyzed by a titanocene complex
Organic Letters, 2001Co-Authors: Hiroyasu Watabe, Jun Terao, Nobuaki KambeAbstract:Symmetrical 1,4-disilyl-2-butenes 1 have been prepared by the reaction of vinyl Grignard Reagent with chlorosilanes. This reaction proceeds efficiently in the presence of a catalytic amount of tita...
Zhangjie Shi - One of the best experts on this subject based on the ideXlab platform.
-
cross coupling of alkenyl aryl carboxylates with Grignard Reagent via fe catalyzed c o bond activation
Journal of the American Chemical Society, 2009Co-Authors: Bingtao Guan, Changliang Sun, Biqin Wang, Zhangjie ShiAbstract:Iron-catalyzed cross-coupling of alkenyl/aryl carboxylates with primary alkyl Grignard Reagent was described. This reaction brought a new family of electrophiles to iron catalysis. The combination of an inexpensive carboxylate electrophile and an iron catalyst would generate ample advantages.
