20802-08-8Relevant academic research and scientific papers
H2O2-mediated room temperature synthesis of 2-arylacetophenones from arylhydrazines and vinyl azides in water
Luo, Mengqiang,Zhang, Yaohong,Fang, Ping,Li, Yan,Qi, Chenze,Li, Yong,Shen, Runpu,Cheng, Kai,Wang, Hai
supporting information, p. 630 - 635 (2022/02/01)
An environmentally benign, cost-efficient and practical methodology for the room temperature synthesis of 2-arylacetophenones in water has been discovered. The facile and efficient transformation involves the oxidative radical addition of arylhydrazines with α-aryl vinyl azides in the presence of H2O2 (as a radical initiator) and PEG-800 (as a phase-transfer catalyst). From the viewpoint of green chemistry and organic synthesis, the present protocol is of great significance because of using cheap, non-toxic and readily available starting materials and reagents as well as amenability to gram-scale synthesis, which provides an attractive strategy to access 2-arylacetophenones.
Palladium-catalyzed synthesis of α-aryl acetophenones from styryl ethers and aryl diazonium saltsviaregioselective Heck arylation at room temperature
Kandasamy, Jeyakumar,Lee, Yong Rok,Singh, Adesh Kumar,Venkatesh, Rapelly
supporting information, p. 7832 - 7837 (2021/09/28)
Preparation of α-aryl acetophenones from styryl ethers and aryldiazonium salts is described. The reaction is catalyzed by palladium acetate at room temperature in the absence of ligand and base. The developed method is highly attractive in terms of reaction conditions, substrate scope, functional group tolerance and yields. Synthetic applications of the present method are demonstrated by preparing α-aryl indoles and 3-aryl isocoumarin from styryl ethers.
Regioselection in the synthesis of 4-benzyltetral-1-ones and the new 4-arylbenzosuber-1-ones
Truong, Daniel,Howard, Brittany L.,Thompson, Philip E.
, (2021/03/09)
The intramolecular Friedel-Crafts acylation of 4,5-diarylpentanoic acids has the possibility to cyclise to either a 6-membered ring to give 4-benzyltetral-1-one or a 7-membered ring to give 4-arylbenzosuber-1-one. Of these, only the former compound class has previously been reported. The impact of the substituents positioning on the outcome of the cyclisation has been investigated. The complete formation of either the tetralone or the benzosuberone regioisomer was possible under the same reaction conditions, dependent upon the ring activation and/or deactivation of the chosen substituents. Selected bromo or methoxy substituents could be used as auxiliaries, included in precursors to afford the desired regioisomer and then subsequently removed.
PtO2/PTSA system catalyzed regioselective hydration of internal arylalkynes bearing electron withdrawing groups
Lin, Hsin-Ping,Ibrahim, Nada,Provot, Olivier,Alami, Mouad,Hamze, Abdallah
, p. 11536 - 11542 (2018/04/05)
A highly efficient PtO2/PTSA catalyst system for the hydration of a wide array of alkynes was developed. This method proved to be compatible with a large range of functional groups and the ketone products were obtained in high yields. The scope of this methodology was also extended to the synthesis of 3-Aryl-isochromenones,-indoles and-benzofurans.
Nitric acid in dichloromethane solution. Facile preparation from potassium nitrate and sulfuric acid
Strazzolini, Paolo,Giumanini, Angelo G.,Runcio, Antonio
, p. 1387 - 1389 (2007/10/03)
Pure dry HNO3 can be liberated from KNO3 with 96% H2SO4 directly into CH2Cl2 to yield solutions of variable concentration for use in a number of organic reactions. The present method efficiently replaces the employment of 100% HNO3 in some synthetic applications, avoiding the problems associated in storage and handling the acid.
Experiments on the Chaperon effect in the nitration of aromatics
Strazzolini, Paolo,Giumanini, Angelo G.,Runcio, Antonio,Scuccato, Massimo
, p. 952 - 958 (2007/10/03)
A nitro group may be effectively delivered to the ortho position of alkylbenzenes, provided that a suitable chaperon function is located in α- position and a dilute of HNO3 in CH2Cl2 is used. The carbonyl function of an aldehyde or ketone is the best choice, but a carboxyl, alkoxycarbonyl, and amide groups all work well. The ether function showed a less pronounced ortho orientation effect, whereas the hydroxyl group was too prone to oxidation. Side reactions were minimal under the conditions employed. A para chaperon effect was seemingly at work in the CH2Cl2 nitration of benzenepropanenitrile. All the results were compared with the corresponding classical nitration in H2SO4.
Substituted (1,2-Diarylethyl)amide Acyl-CoA:Cholesterol Acyltransferase Inhibitors: Effect of Polar Groups on in Vitro and in Vivo Activity
Clader, John W.,Berger, Joel G.,Burrier, Robert E.,Davis, Harry R.,Domalski, Martin,et al.
, p. 1600 - 1607 (2007/10/02)
Substituted (1,2-diarylethyl)amides have been prepared and evaluated for their ability to inhibit microsomal acyl-CoA:cholesterol acyltransferase activity in vitro and to lower hepatic cholesteryl ester content in vivo in a cholesterol-fed hamster.Simple unsubstituted (diarylethyl)amides were potent inhibitors in vitro but showed poor activity in vivo.Introduction of polar groups at specific locations on the diarylethylamine moiety decreased in vitro activity but increased in vivo activity.Both effects were highly structure dependent, suggesting specific interactions which were mediating activity in each model.Optimization of these opposing effects led to compounds which were potent in both models.
Sructure an Mechanism in the Photo-Retro-Aldol Type Reactions of Nitrobenzyl Derivatives. Photochemical Heterolytic Cleavage of C-C Bonds
Wan, Peter,Muralidharan, S.
, p. 4336 - 4345 (2007/10/02)
The photo-retro-aldol type reactions of several nitroaromatic compounds have been studied in aqueous solution over the pH 1-14 range.These reactions are observed only in aqueous or in predominantly aqueous solution.Catalysis of reaction due to hydroxide ion is observed for several derivatives.Quantum yields of reaction and product ratios (of nitrotoluene vs dinitrobibenzyl) are reported as a function of pH.The proposed mechanism of reaction involves heterolytic cleavage of the benzylic C-C bond from the triplet excited state in the primary photochemical step to generate a nitrobenzyl carbanion and a carbocation-equivalent fragment, except for the nitrophenylacetates 24-26, which eliminate CO2 in place of such a fragment.Photogenerated nitrobenzyl carbanions are efficiently trapped by molecular oxygen to give isolable hydroperoxides at pH 9 M-1 s-1.The results show that photochemical C-C bond heterolysis requires favorable stabilization of both the carbanion and carbocation-derived fragments.Hydroxide ion catalysis may also facilitate the process.The use of the nitrobenzyl moiety as the carbanion-stabilizing group appears to be generally applicable, as demonstrated by the systems studied.
