23951-01-1Relevant articles and documents
Aryloxymethyltrifluoroborates for Rhodium-Catalyzed Asymmetric Conjugate Arylation. o-Methoxyarylation through 1,4-Rhodium Shift
Ming, Jialin,Hayashi, Tamio
, p. 6452 - 6455 (2016)
Reaction of potassium aryloxymethyltrifluoroborates 1 with α,β-unsaturated carbonyl compounds 2 in the presence of a chiral diene-rhodium catalyst in H2O at 100 °C introduced 2-methoxyaryl groups at the β-position of 2 with high enantioselectiv
Palladium-Catalyzed Regioselective C–H Acetoxylation of 2-Aryloxypyridines with 2-Pyridyloxy as a Removable Directing Group
Wang, Liang,Pan, Liang,Huang, Yibo,Chen, Qun,He, Mingyang
supporting information, p. 3113 - 3118 (2016/07/12)
A simple and regioselective palladium-catalyzed ortho-C(sp2)–H acetoxylation of 2-aryloxypyridines with PhI(OAc)2as both the oxidant and acetate source has been developed. The mono- and di-acetoxylated products can be achieved by tuning the equivalents of PhI(OAc)2and the reaction temperature. A wide range of 2-aryloxypyridines is tolerated. Moreover, 2-pyridyloxyl and acetyl groups can be easily removed, which provides straightforward access to poly-substituted phenols.
Pd(II) catalyzed ortho C-H iodination of phenylcarbamates at room temperature using cyclic hypervalent iodine reagents
Sun, Xiuyun,Yao, Xia,Zhang, Chao,Rao, Yu
supporting information, p. 10014 - 10017 (2015/06/22)
A novel approach to access ortho iodinated phenols using cyclic hypervalent iodine reagents through palladium(II) catalyzed C-H activation has been developed through weak coordination. The reaction showed excellent regioselectivity, reactivity and good functional group tolerance. A unique mechanism was proposed.
Intramolecular Direct Arylation of 3-Halo-2-pyrones and 2-Coumarins
Nolan, Marie-T.,Pardo, Leticia M.,Prendergast, Aisling M.,McGlacken, Gerard P.
, p. 10904 - 10913 (2015/11/18)
Direct arylation represents a favorable alternative to traditional cross-coupling and has found widespread use with simple aryls and robust heterocycles. Herein a direct arylation protocol has been optimized and applied to 2-pyrones, which are delicate an
Room-temperature Pd-catalyzed C-H chlorination by weak coordination: One-pot synthesis of 2-chlorophenols with excellent regioselectivity
Sun, Xiuyun,Sun, Yonghui,Zhang, Chao,Rao, Yu
supporting information, p. 1262 - 1264 (2014/02/14)
A room-temperature Pd(ii)-catalyzed regioselective chlorination reaction has been developed for a facile one-pot synthesis of a broad range of 2-chlorophenols. The reaction demonstrates an excellent regioselectivity and reactivity for C-H chlorination. This reaction represents one of the rare examples of mild C-H functionalization at ambient temperature.
Intramolecular annulation of aromatic rings with N-sulfonyl 1,2,3-triazoles: Divergent synthesis of 3-methylene-2,3-dihydrobenzofurans and 3-methylene-2,3-dihydroindoles
Tang, Xiang-Ying,Zhang, Yong-Sheng,He, Lv,Wei, Yin,Shi, Min
supporting information, p. 133 - 136 (2015/01/09)
The controllable synthesis of 3-methylene-2,3-dihydrobenzofurans 2 and 3-methylene-2,3-dihydroindoles 5 has been developed through Rh-catalyzed intramolecular annulation of aromatic rings with azavinyl carbenes. This journal is
Palladium-catalyzed decarboxylative coupling of α-oxocarboxylic acids with C(sp2)-H of 2-aryloxypyridines
Yao, Jinzhong,Feng, Ruokun,Wu, Zaihong,Liu, Zhanxiang,Zhang, Yuhong
supporting information, p. 1517 - 1522 (2013/06/27)
An efficient palladium-catalyzed decarboxylative ortho-acylation of 2-aryloxypyridines with α-oxocarboxylic acids is described. In this new transformation, the aromatic C(sp2)-H bond was successfully acylated to give diverse aromatic ketones regioselectively in moderate to good yields. The pyridine group can be removed easily after the acylation to give the corresponding 2-hydroxy aromatic ketones. Copyright
Hydroxy- and aminophenyl radicals from arenediazonium salts
Pratsch, Gerald,Anger, Christian A.,Ritter, Katharina,Heinrich, Markus R.
body text, p. 4104 - 4108 (2011/05/12)
Arenediazonium salts are well-known sources of aryl radicals; however, the hydroxy- and amino-substituted derivatives 1, 2, and 3, which lead to the respective formation of radicals 4, 5, and 6, have rarely been employed in synthetic organic chemistry so far. New synthetic applications of these species have been found, and the properties that may have previously hindered their successful use have been investigated. Copyright
Ketonization equilibria of phenol in aqueous solution
Capponi, Marco,Gut, Ivo G.,Hellrung, Bruno,Persy, Gaby,Wirz, Jakob
, p. 605 - 613 (2007/10/03)
The two keto tautomers of phenol (1), cyclohexa-2,4-dienone (2) and cyclohexa-2,5-dienone (3), were generated by flash photolysis of appropriate precursors in aqueous solution, and the pH-rate profiles of their enolization reactions, 2 → 1 and 3 → 1, were measured. The rates of the reverse reactions, 1 → 2 and 1 → 3, were determined from the rates of acid-catalyzed hydron exchange at the ortho- and para-positions of 1; the magnitude of the kinetic isotope effect was assessed by comparing the rates of hydrogenation of phenol-2t and -2d. The ratios of the enolization and ketonization rate constants provide the equilibrium constants of enolization, pKE(2, aq, 25°C) = -12.73 ± 0.12 and pKE(3, aq, 25°C) = -10.98 ± 0.15. Combination with the acidity constant of phenol also defines the acidity constants of 2 and 3 through a thermodynamic cycle. These ketones are remarkably strong carbon acids: pKa(2) = -2.89 ± 0.12 and pKa(3) = -1.14 ± 0.15. They disappear by proton transfer to the solvent with lifetimes, τ(2) = 260 μs and τ(3) = 13 ms, that are insensitive to pH in the range from 3-10.
