71745-50-1Relevant academic research and scientific papers
Ethylene glycol as hydrogen donor for the syntheses of thymol analogues via hydrolysis of 4-methylcoumarins
Chang, Junbiao,Wang, Shuyang,Shen, Zhenhua,Huang, Gang,Zhang, Yueteng,Zhao, Jing,Li, Changwei,Fan, Fangfang,Song, Chuanjun
supporting information, p. 6755 - 6757,3 (2012/12/12)
Treatment of 4-methylcoumarins with potassium hydroxide in ethylene glycol resulted in the formation of the 'normal' 2-isopropenylphenols and/or the 'abnormal' 2-isopropylphenols depending on the nature of the substrates. The solvent ethylene glycol was b
Dehydrative C-H alkylation and alkenylation of phenols with alcohols: Expedient synthesis for substituted phenols and benzofurans
Lee, Dong-Hwan,Kwon, Ki-Hyeok,Yi, Chae S.
supporting information; experimental part, p. 7325 - 7328 (2012/06/16)
A well-defined cationic Ru-H complex catalyzes the dehydrative C-H alkylation reaction of phenols with alcohols to form ortho-substituted phenol products. Benzofuran derivatives are efficiently synthesized from the dehydrative C-H alkenylation and annulation reaction of phenols with 1,2-diols. The catalytic C-H coupling method employs cheaply available phenols and alcohols, exhibits a broad substrate scope, tolerates carbonyl and amine functional groups, and liberates water as the only byproduct.
Efficient deprotection of phenol methoxymethyl ethers using a solid acid catalyst with Wells-Dawson structure
Romanelli,Autino,Baronetti,Thomas
, p. 1006 - 1011 (2007/10/03)
Deprotection of various phenols from their respective methoxymethyl ethers using an heteropolyacid catalyst was studied. The catalyst was the Wells-Dawson heteropolyacid, used both in bulk or supported on silica. Yields were high to quantitative after less than one hour reaction time and the catalyst was easily recoverable and reusable.
Atropisomerization Barriers of Configurationally Unstable Biaryl Compounds, Useful Substrates for Atroposelective Conversions to Axially Chiral Biaryls
Bringmann, Gerhard,Heubes, Markus,Breuning, Matthias,Goebel, Lothar,Ochse, Michael,Schoener, Bernd,Schupp, Olaf
, p. 722 - 728 (2007/10/03)
Configurationally unstable biaryl lactones of type (M)-1 ? (P)-1 and ring-opened 2-acyl-2′-hydroxy biaryl compounds of type (M)-4 ? (P)-4 are versatile precursors for the atroposelective preparation of axially chiral biaryls. The activation barriers of their atropisomerization process, which constitutes a fundamental precondition for the dynamic kinetic resolution, were determined by dynamic NMR spectroscopy for rapid processes and by HPLC-monitored racemization of enantiomerically enriched material for smaller interconversion rates. For the lactones, the free activation energies ΔG?298 increase with the steric demand of the substituent R ortho to the biaryl axis in the series H 1/2 ≈ ms) 1/2 ≈ s) 1/2 ≈ min) 1/2 ≈ d). The formally ring-opened 2-acyl-2′-hydroxy biaryls, which interconvert via the lactol isomers 5 as the cyclic (and thus configurationally less stable) intermediates, have a significantly slower atropisomerization rate as a result of the high loss in activation entropy ΔS? as a consequence of the required intermediate ring closure 4 → 5.
