104869-89-8Relevant academic research and scientific papers
Porphyrins as Photoredox Catalysts in Csp2-H Arylations: Batch and Continuous Flow Approaches
De Souza, Aline A. N.,Silva, Nathalia S.,Müller, Andressa V.,Polo, André S.,Brocksom, Timothy J.,De Oliveira, Kleber T.
, p. 15077 - 15086 (2019/01/03)
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.
Aerobic, transition-metal-free, direct, and regiospecific mono-α-arylation of ketones: Synthesis and mechanism by DFT calculations
Xu, Qing-Long,Gao, Hongyin,Yousufuddin, Muhammed,Ess, Daniel H.,Kuerti, Laszlo
supporting information, p. 14048 - 14051 (2013/10/21)
We disclose a facile, aerobic, transition-metal-free, direct, and regiospecific mono-α-arylation of ketones to yield aryl benzyl and (cyclo)alkyl benzyl ketones with substitution patterns that are currently inaccessible or challenging to prepare using conventional methods. The transformation is operationally simple, scalable, and environmentally friendly. There is no need for pre-functionalization (i.e., α-halogenation or silyl enol ether formation) or the use of specialized arylating agents (i.e., diaryliodonium salts). DFT calculations suggest that the in situ-generated enolate undergoes direct C-C bond formation with the nitroarene followed by regioselective O2-mediated C-H oxidation.
NUCLEOPHILIC SUBSTITUTION p-DINITROBENZENE WITH SOME CARBANIONS. FORMATION OF p-SUBSTITUTED NITROBENZENES
Iwasaki, Genji,Saeki, Seitaro,Hamana, Masatomo
, p. 31 - 34 (2007/10/02)
Treatment of p-dinitrobenzene with active methylene compounds of rather weak acidity in the presence of t-BuOK in liq NH3 at -70'C leads to nucleophilic substitution of a nitro group, giving p-substituted nitrobenzenes in generally good yields.
A NOVEL NUCLEOPHILIC SUBSTITUTION OF THE FORMYL GROUP IN p-NITROBENZALDEHYDE WITH SOME CARBANIONS
Iwasaki, Genji,Saeki, Seitaro,Hamana, Masatomo
, p. 173 - 176 (2007/10/02)
p-Nitrobenzaldehyde reacts with some active methylene compounds in the presence of a strong base at low temperatures to give p-substituted nitrobenzenes by the two-step course involving the initial formation of the aldol adducts and the subsequent displacement of the carbinol moieties with excess carbanions.
