150-19-6Relevant articles and documents
Synthesis of coumarins via palladium-catalyzed carbonylative annulation of internal alkynes by o-lodophenols
Kadnikov, Dmitry V.,Larock, Richard C.
, p. 3643 - 3646 (2000)
(matrix presented) A variety of substituted coumarins have been prepared in good yields by the palladium-catalyzed coupling of o-iodophenols with internal alkynes and 1 atm of carbon monoxide. Unlike most of the previous work on the palladium-catalyzed carbonylation of alkynes, the insertion of the internal alkyne occurs in preference to the insertion of CO.
Selective production of methoxyphenols from dihydroxybenzenes on alkali metal ion-loaded MgO
Vijayaraj, Munusamy,Gopinath, Chinnakonda S.
, p. 376 - 388 (2006)
Selective O-methylation of dihydroxybenzenes (DHBs; catechol, resorcinol, and hydroquinone) to methoxyphenols (MPs) was carried out with dimethylcarbonate on MgO and alkali metal ion (Li, K, and Cs)-loaded MgO between 523 and 603 K. Catalytic activity and product selectivity varied with respect to DHB substrates. Selectivity for O-methylated products increased with increasing basicity of alkali ions; however, K-MgO showed high and stable activity toward MPs. Selectivity for MPs obtained from three substrates increased in the following order: catechol 2 followed by air and 13C CP-MAS NMR measurements indicated the nature of deposited carbon to be molecular species, graphite, MgCO3 and polyaromatics. XPS revealed the nature and availability of active sites on the spent catalysts, as well as the same changes with reaction conditions and correlated with catalytic activity.
Imidazolium-urea low transition temperature mixtures for the UHP-promoted oxidation of boron compounds
Martos, Mario,Pastor, Isidro M.
, (2022/01/03)
Different carboxy-functionalized imidazolium salts have been considered as components of low transition temperature mixtures (LTTMs) in combination with urea. Among them, a novel LTTM based on 1-(methoxycarbonyl)methyl-3-methylimidazolium chloride and urea has been prepared and characterized by differential scanning calorimetry throughout its entire composition range. This LTTM has been employed for the oxidation of boron reagents using urea-hydrogen peroxide adduct (UHP) as the oxidizer, thus avoiding the use of aqueous H2O2, which is dangerous to handle. This metal-free protocol affords the corresponding alcohols in good to quantitative yields in up to 5 mmol scale without the need of further purification. The broad composition range of the LTTM allows for the reaction to be carried out up to three consecutive times with a single imidazolium salt loading offering remarkable sustainability with an E-factor of 7.9, which can be reduced to 3.2 by the threefold reuse of the system.
Nickel-catalyzed deallylation of aryl allyl ethers with hydrosilanes
Ding, Guangni,Fan, Sijie,Wang, Jingyang,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
supporting information, (2021/09/28)
An efficient and mild catalytic deallylation method of aryl allyl ethers is developed, with commercially available Ni(COD)2 as catalyst precursor, simple substituted bipyridine as ligand and air-stable hydrosilanes. The process is compatible with a variety of functional groups and the desired phenol products can be obtained with excellent yields and selectivity. Besides, by detection or isolation of key intermediates, mechanism studies confirm that the deallylation undergoes η3-allylnickel intermediate pathway.
Method for synthesizing M-hydroxyanisole
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Paragraph 0052-0055; 0058-0059; 0064-0067, (2021/11/03)
The invention provides a method for synthesizing M-hydroxyanisole. Belong to organic synthesis technical field. The synthesis method comprises the following steps: a vapor phase mixture of resorcinol and methanol is subjected to alkylation reaction through a metal phosphate - alumina fixed phase catalyst to obtain m-hydroxyanisole. The method adopts the gas-solid phase alkylation method to synthesize the M-hydroxyanisole without separating the reaction product from the catalyst, has the characteristic of continuous reaction, and can realize continuous production in the industrial production process. The method utilizes the acid-base catalytic activity center on the surface of the stationary phase catalyst to catalyze the reaction of resorcinol and methanol, and has high resorcinol conversion rate. The method has the advantage of high selectivity of m-hydroxyanisole. Methanol is used as a methylation reagent, and the method is environmentally friendly, low in cost and high in economic benefit.