6945-45-5Relevant academic research and scientific papers
Photocatalytic Giese-Type Reaction with Alkylsilicates Bearing C,O-Bidentate Ligands
Morofuji, Tatsuya,Matsui, Yu,Ohno, Misa,Ikarashi, Gun,Kano, Naokazu
supporting information, p. 6713 - 6718 (2021/02/26)
Herein, a photocatalytic Giese-type reaction with alkylsilicates bearing C,O-bidentate ligands as stable alkyl radical precursors has been reported. The alkylsilicates were prepared in one step from organometallic reagents. Not only primary, secondary, and tertiary alkyl radicals, but also elusive methyl radicals, could be generated by using the present reaction system. The generated radicals were trapped by electron-deficient olefins bearing various functional groups to give the desired alkyl adducts. The silicon byproduct can be recovered after the photoreaction. The radical generation process was investigated by theoretical calculations, which provided an insight into the facile generation of methyl radicals from methylsilicate bearing C,O-bidentate ligands.
Selective functionalization of methane, ethane, and higher alkanes by cerium photocatalysis
Hu, Anhua,Guo, Jing-Jing,Pan, Hui,Zuo, Zhiwei
, p. 668 - 672 (2018/09/26)
With the recent soaring production of natural gas, the use of methane and other light hydrocarbon feedstocks as starting materials in synthetic transformations is becoming increasingly economically attractive, although it remains chemically challenging. W
2,4-DIAMINO-6,7-DIHYDRO-5H-PYRROLO[2,3]PYRIMIDINE DERIVATIVES AS FAK/Pyk2 INHIBITORS
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Page/Page column 36-37, (2012/07/27)
The invention relates to a novel class of 2,4-diamino-6,7-dihydro-5H-pyrrolo[2,3]pyrimidine derivatives as a FAK and/or Pyk2 inhibitor, to a process for their preparation, and to a composition thereof, as well as to use of the compounds for the inhibiting FAK and/or Pyk2 and method for the treatment of a FAK and/ or Pyk2 mediated disorder or disease.
Rotation of the exo-methylene group of (R)-3-methylitaconate catalyzed by coenzyme B12-dependent 2-methyleneglutarate mutase from Eubacterium barkeri
Pierik, Antonio J.,Ciceri, Daniele,Broeker, Gerd,Edwards, Christopher H.,McFarlane, William,Winter, Joachim,Buckel, Wolfgang,Golding, Bernard T.
, p. 14039 - 14048 (2007/10/03)
2-Methyleneglutarate mutase from the anaerobe Eubacterium (Clostridium) barkeri is an adenosylcobalamin (coenzyme B12)-dependent enzyme that catalyzes the equilibration of 2-methylene-glutarate with (R)-3-methylitaconate. Two possibilities for the mechanism of the carbon skeleton rearrangement of the substrate-derived radical to the product-related radical are considered. In both mechanisms an acrylate group migrates from C-3 of 2-methyleneglutarate to C-4. In the "addition-elimination" mechanism this 1,2-shift occurs via an intermediate, a 1-methylenecyclopropane-1,2-dicarboxylate radical, in which the migrating acrylate is simultaneously attached to both C-3 and C-4. In the "fragmentation-recombination" mechanism the migrating group, a 2-acrylyl radical, becomes detached from C-3 before it starts bonding to C-4. In an attempt to distinguish between these two possibilities we have investigated the action of 2-methyleneglutarate mutase on the stereospecifically deuterated substrates (Z)-3-methyl[2′-2H1]itaconate and (Z)-3-[2′-2H1,methyl-2H3] methylitaconate. The enzyme catalyzes the equilibration of both compounds with their corresponding E-isomers and with a 1:1 mixture of the corresponding (E)- and (Z)-2-methylene-[2′-2H1]glutarates, as shown by monitoring of the reactions with 1H and 2H NMR. In the initial phase of the enzyme-catalyzed equilibration a significant excess (8-11%) of (E)-3-methyl[2′-2H1]itaconate over its equilibrium value was observed ("E-overshoot"). The E-overshoot was only 3-4% with (Z)-3-[2′-2H1methyl-2 H3]methylitaconate because the presence of the deuterated methyl group raises the energy barrier from 3-methylitaconate to the corresponding radical. The overshoot is explained by postulating that the migrating acrylate group has to overcome an additional energy barrier from the state leading back to the substrate-derived radical to the state leading forward to the product-related radical. It is concluded that the fragmentation-recombination mechanism can provide an explanation for the results in terms of an additional energy barrier, despite the higher calculated activation energy for this pathway.
Use of the Nonionic Superbase P(MeNCH2CH2)3N in the Selective Monoalkylation of Active-Methylene Compounds
Arumugam, Subramaniam,McLeod, Dale,Verkade, John G.
, p. 3677 - 3679 (2007/10/03)
The symmetric active-methylene compounds CH2(CO2Et)2 and CH2[C(O)Me]2 are selectively monoalkylated in the presence of 1.1 equiv of a variety of alkyl halides and 1 equiv of the nonionic Superbase P(MeNCH2CH2)2N in 85-98% yields in 30 min at room temperature. The unsymmetrical active-methylene compound EtO2CCH2C(O)Me is selectively monoalkylated under the same conditions, except for the temperature, which is 0 °C, in 59-88% yields. The observation of selective C- rather than O-alkylation is rationalized in terms of the formation of an enolate whose negatively charged oxygen is sterically protected by a nearby HP(MeNCH2CH2)2N+ counterion in a tight ion pair.
Reduction-alkylation with organocopper(I) reagents-alkyl halydes: Highly regioselective α-alkylation of γ-acetoxy-α,β-enoates with lithium dibutylcuprate-alkyl halides and difference in the reactivity of electron-deficient olefins with organocopper(I)-Lewis acid reagents
Ibuka, Toshiro,Aoyagi, Takeshi,Yamamoto, Yoshinori
, p. 2417 - 2427 (2007/10/02)
Reaction of γ-acetoxy-α,β-enoates with lithium dialkylcuprate followed by alkyl halides results in the predominant or exclusive formation of α-alkyl-β,γ-enoates in high yields under mild conditions, and a synthetic application to (+-)-α-vetispirene is presented.Treatment of diethyl fumarate and triethoxycarbonylethylene with Bu2CuLi*AlCl3 led to 1,4-addition to give conjugate adducts in high yields.In sharp contrast, diethyl maleate and tetraethoxycarbonylethylene predominantly gave the respective reduction products.Evidence for a presumed dianionic intermediate, based on trapping with some electrophyles, is also presented.Keywords - γ-oxygenated α,β-enoate; β,γ-enoate; deconjugative reduction; α-vetispirene; lithium dialkylcuprate; organocopper(I)-Lewis acid.
DIFFERENCES IN THE REACTION OF ELECTRON DEFICIENT OLEFINS WITH ORGANOCOPPER(I)-LEWIS ACID REAGENTS AND EVIDENCE FOR A DIANIONIC EQUIVALENT
Ibuka, Toshiro,Aoyagi, Takeshi,Kitada, Kazuko,Yoneda, Fumio,Yamamoto, Yoshinori
, p. C18 - C22 (2007/10/02)
Treatment of diethyl fumarate and triethoxycarbonylethylene with Bu2CuLi*AlCl3 led to 1,4-addition to give butylated products in high yields.In sharp contrast, diethyl meleate and tetraethoxycarbonylethylene predominantly gave the respective reduction products.The first evidence for a presumed dianionic intermediate by trapping with some electrophiles was also presented.
