2886-52-4Relevant academic research and scientific papers
Photoredox/nickel-catalyzed hydroacylation of ethylene with aromatic acids
Zhang, Lili,Chen, Shuai,He, Hengchi,Li, Weipeng,Zhu, Chengjian,Xie, Jin
supporting information, p. 9064 - 9067 (2021/09/15)
We report a general, practical and scalable hydroacylation reaction of ethylene with aromatic carboxylic acids with the synergistic combination of nickel and photoredox catalysis. Under ambient temperature and pressure, feedstock chemicals such as ethylene can be converted into high-value-added aromatic ketones in moderate to good yields (up to 92%) with reaction time of 2-6 hours.
Broadening the catalyst and reaction scope of regio- and chemoselective C-H oxygenation: A convenient and scalable approach to 2-acylphenols by intriguing Rh(ii) and Ru(ii) catalysis
Shan, Gang,Han, Xuesong,Lin, Yun,Yu, Shanyou,Rao, Yu
supporting information, p. 2318 - 2322 (2013/04/10)
A unique Rh(ii) and Ru(ii) catalyzed C-H oxygenation of aryl ketones and other arenes has been developed for the facile synthesis of diverse functionalized phenols. The reaction demonstrates excellent reactivity, regio- and chemoselectivity, good functional group compatibility and high yields. The practicality of this method has been proved by gram-scale synthesis of a few different 2-acylphenols. Its utility has been well exemplified in further applications in heterocycle synthesis and direct modifications of drug Fenofibrate.
Comparisons of O-acylation and Friedel-Crafts acylation of phenols and acyl chlorides and Fries rearrangement of phenyl esters in trifluoromethanesulfonic acid: Effective synthesis of optically active homotyrosines
Murashige, Ryo,Hayashi, Yuka,Ohmori, Syo,Torii, Ayuko,Aizu, Yoko,Muto, Yasuyuki,Murai, Yuta,Oda, Yuji,Hashimoto, Makoto
experimental part, p. 641 - 649 (2011/03/19)
Reactions involving phenol derivatives and acyl chlorides have to be controlled for competitive O-acylations and C-acylations (Friedel-Crafts acylations and Fries rearrangements) in acidic condition. The extent for these reactions in trifluoromethanesulfonic acid (TfOH), which is used as catalyst and solvent, is examined. Although diluted TfOH was needed for effective O-acylation, concentrated TfOH was required for effective C-acylations in mild condition. These results have been applied to the novel synthesis of homotyrosine derivatives. Both Fries rearrangement of N-TFA-Asp(OBn)-OMe and Friedel-Crafts acylation of phenol with N-TFA-Asp(Cl)-OMe in TfOH afforded the homotyrosine skeleton, followed by reduction and deprotection afforded homotyrosines maintaining stereochemistry of Asp as an optically pure form.
A REEXAMINATION OF THE RETRO-FRIES REARRANGEMENT OF SOME o-HYDROXYKETONES
Martin, Robert,Lafrance, Jean Ronald,Demerseman, Pierre
, p. 539 - 548 (2007/10/02)
The retro-Fries rearrangement, catalyzed by protic and Lewis acids, was studied for some o-hydroxyketones.The results are consistent with the mechanism of an heterolytic cleavage and rearrangement.It appears that, in general, Lewis acids do not induce the retro-Fries rearrangement of o-hydroxyketones.However, in certain cases, it may be brought about the presence of a protic acid generated in situ, from a solvent-catalyst interaction.
Lewis Acids Catalysed Fries Rearrangement of Isopropylcresol Esters
Martin, Robert,Demerseman, Pierre
, p. 227 - 236 (2007/10/02)
In the course of the Fries rearrangement, aluminium chloride frequently induces migration or elimination of alkyl groups.The results obtained with titanium tetrachloride for the synthesis of vicinal o-hydroxyketones are compared with those obtained with aluminium chloride for some aliphatic and aromatic esters of isopropylcresols.In order to understand the migration and elimination processes occurring, the stabilities of the o-hydroxyketones are studied in the presence of aluminium chloride at different temperatures.Furthermore, all-vicinal o-hydroxyketones were prepared by the Fries rearrangement of 6-tert-butyl-p-thymol with titanium tetrachloride.
