52648-78-9Relevant academic research and scientific papers
Selective C-C Bond Cleavage of Cycloalkanones by NaNO2/HCl
He, Tianyu,Chen, Dengfeng,Qian, Shencheng,Zheng, Yu,Huang, Shenlin
supporting information, p. 6525 - 6529 (2021/09/02)
A novel selective fragmentation of cycloalkanones by NaNO2/HCl has been established. The C-C bond cleavage reaction proceeds smoothly under mild conditions, selectively affording versatile keto acids or oxime acids. The methodology can streamline the synthesis of valuable chiral molecules and isocoumarins from readily available feedstocks.
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.
Visible-light-mediated α-arylation of enol acetates using aryl diazonium salts
Hering, Thea,Hari, Durga Prasad,Koenig, Burkhard
, p. 10347 - 10352 (2013/01/15)
Visible light mediates efficiently the α-arylation of enol acetates by aryl diazonium salts under mild conditions using [Ru(bpy)3]Cl 2 as a photoredox catalyst. The broad scope of the reaction toward various diazonium salts and enol acetates was explored. The application of this reaction in the concise synthesis of 2-substituted indoles was demonstrated
Palladium-catalyzed regiocontrolled α-arylation of trimethylsilyl enol ethers with aryl halides
Iwama, Tetsuo,Rawal, Viresh H.
, p. 5725 - 5728 (2007/10/03)
(Diagram presented) Inter- and intramolecular arylations of trimethylsilyl enol ethers with aryl halides are accomplished regiospecifically in the presence of a palladium catalyst and tributyltin fluoride in refluxing benzene or toluene. The optimal catalyst system called for the use of Pd 2(dba)3 and tri-tert-butylphosphine in ca. 1:2 ratio. Aryl iodides, bromides, and chlorides are all effective arylation partners in this reaction.
Two useful photolabile surfaces for solid-phase synthesis
Ryba, Troy D.,Harran, Patrick G.
, p. 851 - 853 (2007/10/03)
formula presented o-Nitrobenzyl-based photolabile surfaces 3 and 4 have been synthesized from 2-phenylcyclohexanone and aminopropylsiloxane-grafted controlled pore glass. The procedures are simple and inexpensive and generate materials whose minimally fun
SUBSTITUENT EFFECTS ON THE REGIO- AND STEREOSELECTIVITY OF GAS-PHASE ACID-INDUCED RING OPENING IN 1-ARYLCYCLOHEXENE OXIDES
Cecchi, P.,Pizzabiocca, A.,Renzi,G.,Chini, M.,Crotti, P.,et al.
, p. 4227 - 4234 (2007/10/02)
Comparative analysisof the ratio of the isomeric monomethyl ethers of 1-arylcyclohexane-1,2-diols formed in the gas-phase and solvolytic acid-induced methanolysis of several 1-arylcyclohexene oxides indicates the intrinsic electronic factors detrminimg the regio- and stereochemical course of the nucleophilic attack, related to the partial degree of carbocationic character at the reaction centre in the substitution transition state.
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.
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.
Nucleophilic Addition of Silyl Enol Ethers to Aromatic Nitro Compounds: Scope and Mechanism of Reaction
RajanBabu, T. V.,Reddy, G. S.,Fukunaga, Tadamichi
, p. 5473 - 5483 (2007/10/02)
In sharp contrast to alkali-metal enolates, silyl enol ethers and ketene silyl acetals add to aromatic nitro compounds in the presence of a fluoride ion source to give the intermediate dihydroaromatic nitronates, which can be observed by NMR.In situ oxidation of the intermediate with bromine or DDQ yields α-nitroaryl carbonyl compounds in moderate-to-high yields.The reaction is applicable to alkyl-, alkoxy-, and halogen-substituted nitrobenzenes as well as to heterocyclic and condensed nitroaromatic compounds.While substitution ortho to the nitro group predominates with sterically undemanding silyl reagents, para-substitution products are exclusively obtained with bulky reagents.However, by blocking the para position with an appropriate group such as chlorine, the addition can be directed to the ortho position.Halogen atoms of halogenated nitroaromatics and p-nitrocumenyl chloride are not displaced in the reaction, suggesting the absence of radical ion intermediates.Dihydroaromatic nitro derivatives ca be isolated in some cases, such as anthracene and naphthalene systems which are less prone to rearomatize.
