33155-61-2Relevant academic research and scientific papers
Synthesis of Rhodium Complexes with Chiral Diene Ligands via Diastereoselective Coordination and Their Application in the Asymmetric Insertion of Diazo Compounds into E?H Bonds
Ankudinov, Nikita M.,Chusov, Denis A.,Nelyubina, Yulia V.,Perekalin, Dmitry S.
supporting information, p. 18712 - 18720 (2021/07/20)
A new method for the synthesis of chiral diene rhodium catalysts is introduced. The readily available racemic tetrafluorobenzobarrelene complexes [(R2-TFB)RhCl]2 were separated into two enantiomers via selective coordination of one of them with the auxiliary S-salicyl-oxazoline ligand. One of the resulting chiral complexes with an exceptionally bulky diene ligand [(R,R-iPr2-TFB)RhCl]2 was an efficient catalyst for the asymmetric insertion of diazoesters into B?H and Si?H bonds giving the functionalized organoboranes and silanes with high yields (79–97 %) and enantiomeric purity (87–98 % ee). The stereoselectivity of separation via auxiliary ligand and that of the catalytic reaction was predicted by DFT calculations.
Photoinduced Palladium-Catalyzed Negishi Cross-Couplings Enabled by the Visible-Light Absorption of Palladium–Zinc Complexes
Abdiaj, Irini,Huck, Lena,Mateo, José Miguel,de la Hoz, Antonio,Gomez, M. Victoria,Díaz-Ortiz, Angel,Alcázar, Jesús
supporting information, p. 13231 - 13236 (2018/09/25)
A visible-light-induced Negishi cross-coupling is enabled by the activation of a Pd0–Zn complex. With this photocatalytic method, the scope of deactivated aryl halides that can be employed in the Negishi coupling was significantly expanded. NMR experiments conducted in the presence and absence of light confirmed that the formation of the palladium–zinc complex is key for accelerating the oxidative addition step.
Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
Ma, Xiaoshen,Herzon, Seth B.
, p. 8673 - 8695 (2016/10/17)
Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including alkenyl halides, sulfides, triflates, and phosphonates and provides a mild and practical alternative to the Tamao-Fleming oxidation of vinylsilanes and the Arndt-Eistert homologation.
Copper-catalyzed coupling of aryl iodides and tert-butyl keto esters: Efficient access to α-aryl ketones and α-arylacetic acid tert-butyl esters
Zhao, Duo,Jiang, Yongwen,Ma, Dawei
, p. 3327 - 3332 (2014/05/06)
CuI/trans-4-hydroxy-l-proline catalyzed coupling of aryl iodides with tert-butyl keto esters proceeded smoothly at 40 °C in DMF, providing α-aryl ketones after acid-promoted deprotection and decarboxylation of tert-butyl ester group. While CuI/2-picolinic acid catalyzed coupling of aryl iodides with tert-butyl acetoacetate at 70 °C in dioxane delivered α-arylacetic acid tert-butyl esters upon spontaneous deacylation. A wide range of functional groups, such as acetyl, methoxy, nitrile, nitro, bromo, and chloro were compatible with the reaction conditions.
Iron-catalyzed chemoselective cross-coupling of α-bromocarboxylic acid derivatives with aryl grignard reagents
Jin, Masayoshi,Nakamura, Masaharu
scheme or table, p. 1012 - 1014 (2011/12/05)
We have developed a simple and effective synthetic method of α-arylcarboxylic acid derivatives based on the iron-catalyzed cross-coupling reaction of α-bromocarboxylic acid derivatives with aryl Grignard reagents. The reaction proceeds smoothly at -78 °C in a chemoselective manner to produce the coupling product in good to excellent yields.
Photophysics and photodeprotection reactions of p -methoxyphenacyl phototriggers: An ultrafast and nanosecond time-resolved spectroscopic and density functional theory study
An, Hui-Ying,Kwok, Wai Ming,Ma, Chensheng,Guan, Xiangguo,Kan, Jovi Tze Wai,Toy, Patrick H.,Phillips, David Lee
scheme or table, p. 5837 - 5851 (2010/10/03)
Time-resolved spectroscopic experiments were performed to investigate the kinetics and mechanisms of the photodeprotection reactions for p-methoxyphenacyl (pMP) compounds, p-methoxyphenacyl diethyl phosphate (MPEP) and diphenyl phosphate (MPPP). The experimental results reveal that compared to the previous reports for the counterpart p-hydroxyphenacyl (pHP) phosphates, the 3nπ/ππ* mixed character triplet of pMP acts as a reactive precursor that leads to the subsequent solvent and leaving group dependent chemical reactions and further affects the formation of photoproducts. The MPPP triplet in H2O/CH3CN and in fluorinated alcohols shows a rapid heterolytic cleavage (τ ≈ 5.4 ns) that results in deprotection and formation of a solvolytic rearrangement product, whereas the MPPP triplet in CH3CN and the MPEP triplet in CH3CN and H2O/CH3CN and fluorinated alcohols decay on a much longer time scale (τ ≈ 100 ns) with little observation of the rearrangement product. The density functional theory (DFT) calculations reveal a substantial solvation effect that is connected with the methoxy versus hydroxyl substitution in accounting for the different deprotection reactivity of pMP and pHP compounds. The results reported here provide new insight in elucidating the solvent and leaving group dependent dual reactivity of pMP compounds on the formation of the rearrangement versus reductive photoproduct.
Using benzotriazole esters as a strategy in the esterification of tertiary alcohols
Morales-Serna, Jose Antonio,Vera, Aline,Paleo, Ehecatl,Garcia-Rios, Erendira,Gavino, Ruben,Garcia De La Mora, Gustavo,Cardenas, Jorge
experimental part, p. 4261 - 4267 (2011/02/25)
Benzotriazole esters formed in situ were found to be efficient intermediates in the esterification of tertiary alcohols using 4-(dimethylamino)pyridine (DMAP) as the base. These mild and basic reaction conditions allow the conversion of various substrates into esters in good yield
Selective monoarylation of acetate esters and aryl methyl ketones using aryl chlorides
Biscoe, Mark R.,Buchwald, Stephen L.
supporting information; experimental part, p. 1773 - 1775 (2009/09/06)
Simple, efficient procedures for the monoarylation of acetate esters and aryl methyl ketones using aryl chlorides are presented. Previously, no general method was available to ensure the highly selective monoarylation of these classes of substrates using
