116557-45-0Relevant academic research and scientific papers
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.
Pd-catalyzed C-H oxygenation with TFA/TFAA: Expedient access to oxygen-containing heterocycles and late-stage drug modification
Shan, Gang,Yang, Xinglin,Ma, Linlin,Rao, Yu
supporting information, p. 13070 - 13074 (2013/02/26)
Functionalized phenols are valuable industrial chemicals related to pharmaceuticals, agrochemicals, and polymers. Therefore, the direct catalytic hydroxylation of arenes to produce phenols has attracted much attention. Although tremendous progress has been made in this field, there are still difficult substrates which remain unmet challenges for direct hydroxylation in terms of regio- and chemoselectivity, as well as the practicality of current methods (Scheme 1). For example, 2-hydroxy aromatic ketones are useful synthetic intermediates for the preparation of various oxygen-containing heterocycles such as benzofuranone, chromanone, benzoxazole, and dibenzooxazepine; they also serve as key building blocks for drugs such as celiprolol, acebutolol, and propafenone. Traditional strategies for accessing 2-hydroxy aromatic ketones have mainly involved the oxidation of benzylic alcohols, the hydrolysis of aromatic halides, Fries rearrangement of esters or the demethylation of methyl phenyl ether. These methods generally suffer from one limitation or another, such as tedious reaction procedures, harsh reaction conditions, low yields, or the formation of side products. Hence, direct transformation of readily available aromatic ketones into valuable 2-hydroxylated products by transition metal-catalyzed C-H functionalization is arguably a highly efficient and atom-economic method to access these compounds. Moreover, developing a more general strategy for the regio- and chemoselective C-H oxygenation of a variety of challenging arenes would be especially desirable for phenol synthesis (Scheme 1).
Improvement of Selectivity in the Fries Rearrangement and Direct Acylation Reactions by Means of P2O5/SiO2 Under Microwave Irradiation in Solvent-Free Media
Eshghi, Hossein,Rafie, Mohammad,Gordi, Zinat,Bohloli, Moosa
, p. 1258 - 1270 (2007/10/03)
P2O5/SiO2 was found to be an efficient new reagent for the Fries rearrangement of acyloxy benzene or naphthalene derivatives and the direct acylation reactions of phenol and naphthol derivatives with carboxylic acids. The reactions proceeded smoothly in the solid state and are highly selective methods for the preparation of the ortho isomers of hydroxyaryl ketones. Microwave irradiation improved the conversion yield to 85-100 percent and the high ortho-regioselectivity of these reactions provides an efficient and versatile procedure for obtaining o-hydroxyaryl ketones in 47-98 percent yield.
