93434-58-3Relevant academic research and scientific papers
Visible-Light-Driven, Metal-Free Divergent Difunctionalization of Alkenes Using Alkyl Formates
Zheng, Ming,Hou, Jing,Zhan, Le-Wu,Huang, Yan,Chen, Ling,Hua, Li-Li,Li, Yan,Tang, Wan-Ying,Li, Bin-Dong
, p. 542 - 553 (2021/01/14)
In recent decades, difunctionalization of alkenes has received considerable attention as an efficient and straightforward way to increase molecular complexity. However, examples of the difunctionalization of alkenes initiated by the intermolecular addition of alkoxycarbonyl radicals providing substituted alkanoates are still rare. Herein, we present the visible light-driven metal-free divergent difunctionalization of alkenes triggered by the intermolecular addition of alkoxycarbonyl radicals under ambient conditions. Employing alkyl formates as precursors of alkoxycarbonyl radicals and 4CzIPN as the photocatalyst, a variety of substituted alkanoates, including β-alkoxy, β-hydroxy, β-dimethoxymethoxy, and β-formyloxy alkanoates, could be facilely accessed with high functional group tolerance and high efficiency. Moreover, the mechanism study revealed that β-hydroxy alkanoates were generated by a selective decomposition of orthoformates promoted by the N-alkoxyazinium salt.
Overriding effect of temperature over reagent and substrate size for boron-mediated aldol reaction of methyl phenylacetate
Ramachandran, P. Veeraraghavan,Chanda, Prem B.
supporting information, p. 5886 - 5888 (2013/10/21)
The enolization temperature overrides all other aspects, including the sterics of the alkyl group of the boron reagent and the alkoxy group of the ester during the enolboration-aldolization of phenylacetates. This study has led to the first n-Bu2/su
Discovery of a novel class of aldol-derived 1,2,3-triazoles: Potent and selective inhibitors of human cytochrome P450 19A1 (aromatase)
McNulty, James,Nair, Jerald J.,Vurgun, Nesrin,Difrancesco, Benjamin R.,Brown, Carla E.,Tsoi, Bernice,Crankshaw, Denis J.,Holloway, Alison C.
supporting information; experimental part, p. 718 - 722 (2012/03/11)
The discovery of a novel five-component 1,2,3-triazole-containing pharmacophore that exhibits potent and selective inhibition of aromatase (CYP 450 19A1) is described. All compounds are derived from an initial aldol reaction of a phenylacetate derivative
Solvent- or temperature-controlled diastereoselective aldol reaction of methyl phenylacetate
Ramachandran, P. Veeraraghavan,Chanda, Prem B.
, p. 4346 - 4349 (2012/10/29)
Unlike the enolboration-aldolization of methyl propanoate, the choice of either the solvent or temperature determines the diastereoselectivity during the enolboration-aldolization of methyl phenylacetate. In CH2Cl 2, the reaction favors the anti-pathway at -78 °C and the syn-pathway at rt. Conversely, the reaction produces the anti-isomer up to rt and the syn-isomer at refluxing temperatures in nonpolar solvents.
Kinetics and mechanism of the oxidation of alkenes by chromium(VI) in the presence of complexing agents
Meenakshisundaram, Subbiah,Gopalakrishnan,Nagarajan,Sarathi,Sumathi
, p. 73 - 79 (2007/10/03)
The catalytic activities of 2,2′-bipyridyl (bipy) and oxalic acid (Oxa) in the HCrO4- oxidation of some substituted trans-cinnamic acids have been investigated in acidic solutions. The Cr(VI)-bipy and Cr(VI)-Oxa complexes are believed to be the probable reactive electrophiles in this redox process. The kinetic data reveal that electron-releasing groups enhance the reactivity to a significant extent while the electron-withdrawing ones reduce the rate marginally. It appears that the mechanism of bipy/Oxa catalysed chromium(VI) oxidation of unsaturated systems to the corresponding cleavage products involves an electrophilic attack of the reactive complex at the C-C double bond. The formation of a ternary complex as an intermediate is envisaged to describe the redox process. In this paper, we also report on the kinetic form of the oxidation of trans-stilbene to methyl 3-hydroxy-2,3-diphenylpropanoate. The mechanistic pathway has been determined based on the kinetic behaviour and the product assignment.
Control of diastereoselectivity in the aldolization of methyl phenylacetate
Pinheiro, Sergio,Lima, Marcelo B.,Gon?alves, Clara B.S.S.,Pedraza, Sérgio F.,De Farias, Florence M.C.
, p. 4033 - 4034 (2007/10/03)
The aldolization of methyl phenylacetate with benzaldehyde in several conditions was studied. While the use of LDA in THF-HMPA gave the anti-aldol, the dibutylboron triflate furnished the syn-aldol in high diastereoselectivity (syn:anti=97:3). (C) 2000 El
The Phenyldimethylsilyl Group as a Masked Hydroxy Group
Fleming, Ian,Henning, Rolf,Parker, David C.,Plaut, Howard E.,Sanderson, Philip E. J.
, p. 317 - 338 (2007/10/02)
A phenyldimethylsilyl group attached to carbon can be converted into hydroxy group 1->5, with retention of configuration at the migrating carbon, by any of three main methods.The first involves protodesilylation, to remove the phenyl ring from the silicon atom, followed by oxidation of the resulting functionalized silicon atom using peracid or hydrogen peroxide.The second uses mercuric acetate for the same purpose, and can be combined in one pot with the oxidative step using peracetic acid.This method has a variant in which the mercuric ion is combined with palladium(II) acetate, both in less than stoichiometric amounts.The third uses bromine, which can also be used in one pot in conjuction with peracetic acid.In this method, but not in the method based on mercuric acetate, the peracetic acid may be buffered with sodium acetate.The method using bromine as the electrophile for removing the benzene ring has a more agreeable variant in which it is administered in the form of potassium bromide, which is oxidised to bromine by the peracetic acid.The scope and limitations of each of these methods are reported with a range of examples possessing between them many of the common functional groups.Simple benzene rings, alcohols, ethers, esters, amides and nitriles are compatible with all three methods, and ketones do not undergo Baeyer-Villiger reaction under any of the conditions.Amines, however, are oxidised to amine oxides.Ketones may be brominated in the third of the three main species.The absence of acid in the third method makes it especially valuable when the phenyldimethylsilyl group has a neighbouring nucleofugal group such as hydroxy or acetoxy.Carbon-carbon double bonds are incompatible with the methods, except for terminal monosubstituted double bonds, which can survive the conditions used in the first of the three methods.
Stereoselective reduction of 2-methyl-3-oxo esters (or amides) with sodium borohydride catalyzed by manganese (II) chloride or tetrabutylammonium borohydride. A practical preparation of erythro and threo-3-hydroxy-2-methyl esters (or amides)
Taniguchi, Masahiko,Fujii, Hideaki,Oshima, Koichiro,Utimoto, Kiitiro
, p. 11169 - 11182 (2007/10/02)
erythro-3-Hydroxy-2-methylpropionates or erythro-3-hydroxy-2-methylpropionamides were prepared with high stereoselectivity by NaBH4 reduction of the corresponding 2-methyl-3-oxo esters or 2-methyl-3-oxo amides in the presence of a catalytic amount of manganese(II) chloride. On the other hand, reduction of these substrates with n-Bu4NBH4 provided threo-isomers selectively. erythro-Selective reduction of 2-methyl-3-oxo amides with NaBH3CN in 1N HCl-MeOH is also described.
Influence of the Enol Formation on the Reduction of β-Keto Carboxylic Acid Derivatives by Zinc Borohydride
Meier, Herbert,Krause, Volker
, p. 1713 - 1719 (2007/10/02)
Reduction of Carbonyl Ester Groups, Chemoselectivity, StereoselectivityDepending on the keto-enol equilibrium 12 reduction of the esters and the amides 1/2 a-g with Zn(BH4)2/ZnCl2 attacks either at the CO or at the CO2R group.A high diastereoselectivit
