Takahide Fukuyama
Osaka Prefecture University
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Publication
Featured researches published by Takahide Fukuyama.
Journal of the American Chemical Society | 2009
Gilles Lemière; Vincent Gandon; Kevin Cariou; Alexandra Hours; Takahide Fukuyama; Anne-Lise Dhimane; Louis Fensterbank; Max Malacria
Cyclopentenylidene gold complexes can easily be formed from vinyl allenes through a Nazarov-like mechanism. Such carbenes may transform in four different ways into polycyclic frameworks: electrophilic cyclopropanation, C-H insertion, C-C migration, or proton shift. We have studied the selectivity of these different pathways and used our findings for the expedient preparation of valuable complex molecules. An application to the total synthesis of a natural product, Delta(9(12))-capnellene, is presented. DFT computations were carried out to shed light on the mechanisms.
Accounts of Chemical Research | 2014
Shuhei Sumino; Akira Fusano; Takahide Fukuyama; Ilhyong Ryu
Numerous methods for transition metal catalyzed carbonylation reactions have been established. Examples that start from aryl, vinyl, allyl, and benzyl halides to give the corresponding carboxylic acid derivatives have all been well documented. In contrast, the corresponding alkyl halides often encounter difficulty. This is inherent to the relatively slow oxidative addition step onto the metal center and subsequent β-hydride elimination which causes isomerization of the alkyl metal species. Radical carbonylation reactions can override such problems of reactivity; however, carbonylation coupled to iodine atom transfer (atom transfer carbonylation), though useful, often suffers from a slow iodine atom transfer step that affects the outcome of the reaction. We found that atom transfer carbonylation of primary, secondary, and tertiary alkyl iodides was efficiently accelerated by the addition of a palladium catalyst under light irradiation. Stereochemical studies support a mechanistic pathway based on the synergic interplay of radical and Pd-catalyzed reaction steps which ultimately lead to an acylpalladium species. The radical/Pd-combined reaction system has a wide range of applications, including the synthesis of carboxylic acid esters, lactones, amides, lactams, and unsymmetrical ketones such as alkyl alkynyl and alkyl aryl ketones. The design of unique multicomponent carbonylation reactions involving vicinal C-functionalization of alkenes, double and triple carbonylation reactions, in tandem with radical cyclization reactions, has also been achieved. Thus, the radical/Pd-combined strategy provides a solution to a longstanding problem of reactivity involving the carbonylation of alkyl halides. This novel methodology expands the breadth and utility of carbonylation chemistry over either the original radical carbonylation reactions or metal-catalyzed carbonylation reactions.
Journal of the American Chemical Society | 2008
Sohei Omura; Takahide Fukuyama; Jiro Horiguchi; Yuji Murakami; Ilhyong Ryu
An efficient cross-addition reaction of dienes with aldehydes was developed by using RuHCl(CO)(PPh3)3 as a catalyst to give a wide variety of beta,gamma-unsaturated ketones, where a pi-allylruthenium species, derived from hydroruthenation of diene, may be involved as a key intermediate.
Organic Letters | 2010
Akira Fusano; Takahide Fukuyama; Satoshi Nishitani; Takaya Inouye; Ilhyong Ryu
Under photoirradiation conditions using xenon light, in the presence of a catalytic amount of PdCl(2)(PPh(3))(2) with triethylamine as a base, a three-component coupling reaction of iodoalkanes, carbon monoxide, and terminal alkynes proceeded to give alkyl alkynyl ketones in good yields.
Organic Letters | 2008
Takahide Fukuyama; Masahide Kobayashi; Md. Taifur Rahman; Naoya Kamata; Ilhyong Ryu
Tributyltin hydride-mediated radical reactions of organic halides were successfully carried out in a continuous flow system using a microreactor. The reactions proceeded within a very short period of time, coupled with quickly decomposing radical initiators such as V-65 and V-70. The continuous flow reaction system was applied to gram scale synthesis of a key intermediate for furofuran lignans.
Chemical Science | 2014
Megumi Okada; Takahide Fukuyama; Keiichi Yamada; Ilhyong Ryu; Davide Ravelli; Maurizio Fagnoni
Sunlight-induced direct regioselective β-alkylation of cyclopentanones with electron-deficient alkenes was accomplished by using tetrabutylammonium decatungstate (TBADT) as the catalyst. The regiochemistry can be rationalized by a polar transition state for an SH2 reaction. In the presence of CO, the reaction gave the three-component β-acylation product in good yield.
Organic Letters | 2013
Ilhyong Ryu; Akihiro Tani; Takahide Fukuyama; Davide Ravelli; Sara Montanaro; Maurizio Fagnoni
Tetrabutylammonium decatungstate (TBADT) accelerated the addition of C-H bonds to the N═N double bond of diisopropyl azodicarboxylate (DIAD) under irradiation conditions. The photoinduced three-component coupling between cyclic alkanes, CO, and DIAD was also achieved to give the corresponding acyl hydrazides.
Organic Letters | 2008
Ilhyong Ryu; Shohei Uehara; and Hidefumi Hirao; Takahide Fukuyama
Tin-free Giese reaction and the related radical carbonylation process proceeded efficiently in the presence of sodium cyanoborohydride and tetrabutylammonium cyanoborohydride. The reaction took place chemoselectively at the carbon-iodine bond but not at the carbon-bromine and carbon-chlorine bonds. The iodine atom transfer followed by hydride reduction of the resulting carbon-iodine bond is proposed as a possible mechanism.
Angewandte Chemie | 2010
Kyoung-Ik Min; Tae‐Ho Lee; Chan Pil Park; Zhiyong Wu; Hubert H. Girault; Ilhyong Ryu; Takahide Fukuyama; Yu Mukai; Dong-Pyo Kim
Glass, silicon, poly(dimethylsil-oxane) (PDMS), and poly(methylmethacrylate) (PMMA)have been used for the fabrication of miniaturized devices.Fabrication with glass or silicon substrates requires relativelycomplex processes, and the fabrication costs are high.Relatively cheap polymers such as PDMS or PMMA arenot suitable for application in organic chemical processesowing to their low chemical stability and easy swelling.
Organic Letters | 2009
Inga C. Wienhöfer; Armido Studer; Md. Taifur Rahman; Takahide Fukuyama; Ilhyong Ryu
Highly efficient thermal radical carboaminoxylations of various olefins by using the novel alkoxyamine A to give adducts of type B are described. It is reported that these radical addition reactions can be performed in a microflow reaction system. As compared to conventional batch reaction setup, significantly higher yields are obtained by running carboaminoxylations using the microflow system under analogous conditions.