- Iron powder and tin/tin chloride as new reducing agents of Meerwein arylation reaction with unexpected recycling to anilines
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Simple and rapid route for Meerwein arylation reaction using iron powder or a mixture of tin/tin chloride has been developed. In the presence of iron powder, different aryl diazonium salts reacted with methyl vinyl ketone, acrylates, and isopropenyl acetate. Production of oximes was detected as the main product with acrylates or in a mixture with β-aryl methyl ketones in the case of methyl vinyl ketone. The in situ produced HNO2 from an excess of NaNO2/HCl was trapped by alkyl aryl radical to form oximes in the E configuration form. The presence of tin/tin chloride mixture in the reaction of the aryl diazonium salts with methyl vinyl ketone produced Michael products along with β-aryl methyl ketones. The predicted α-aryl methyl ketones from the reaction of isopropenyl acetate with the diazotized anilines were obtained using iron or tin/tin chloride mixture.
- Abdelwahab, Ahmed B.,El-Sawy, Eslam R.,Kirsch, Gilbert
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supporting information
p. 526 - 538
(2020/01/08)
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- Porphyrins as Photoredox Catalysts in Csp2-H Arylations: Batch and Continuous Flow Approaches
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We have investigated both batch and continuous flow photoarylations of enol-acetates to yield different α-arylated aldehyde and ketone building blocks by using diazonium salts as the aryl-radical source. Different porphyrins were used as SET photocatalysts, and photophysical as well as electrochemical studies were performed to rationalize the photoredox properties and suggest mechanistic insights. Notably, the most electron-deficient porphyrin (meso-tetra(pentafluorophenyl)porphyrin) shows the best photoactivity as an electron donor in the triplet excited state, which was rationalized by the redox potentials of excited states and the turnover of the porphyrins in the photocatalytic cycle. A two-step continuous protocol and multigram-scale reactions are also presented revealing a robust, cost-competitive, and easy methodology, highlighting the significant potential of porphyrins as SET photocatalysts.
- De Souza, Aline A. N.,Silva, Nathalia S.,Müller, Andressa V.,Polo, André S.,Brocksom, Timothy J.,De Oliveira, Kleber T.
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p. 15077 - 15086
(2019/01/03)
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- Palladium-catalyzed mono-α-arylation of acetone with aryl imidazolylsulfonates
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Set the ace(tone): A palladium catalyst derived from the bidentate XantPhos ligand and Pd(OAc)2 has enabled broadly applicable mono-α-arylations of acetone to be performed with air- and moisture-stable aryl imidazolylsulfonates as most user-friendly electrophiles (see scheme). Copyright
- Ackermann, Lutz,Mehta, Vaibhav P.
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supporting information; experimental part
p. 10230 - 10233
(2012/09/22)
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- Arylethanolamine derivatives, their preparation and use in pharmaceutical compositions
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Compounds of formula (II): STR1 or a pharmaceutically acceptable salt thereof, in which X is an oxygen atom or a bond, R1 is a hydrogen, fluorine, chlorine or bromine atom or a trifluoromethyl or C1-4 alkyl group, each of R2 and R3 is a hydrogen atom or a C1-4 alkyl group, R4 is a C1-4 alkyl group, R5 is a hydrogen atom or a C1-4 alkyl group, and n is an integer of from 1 to 3; are useful as anti-obesity and/or anti-hyperglycaemic agents.
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