- Iron-catalyzed conversion of unactivated aryl halides to phenols in water
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Although iron is low-cost and environmentally friendly, there is no report about iron-catalyzed conversion of unactivated aryl halides to phenols. In this Letter, a new method for the present conversion was developed with iron compounds as the catalyst and water as the solvent. The suggested method allowed a series of unactivated aryl bromides and aryl iodides to be converted into the corresponding substituted phenols in moderate to high yields.
- Ren, Yunlai,Cheng, Lin,Tian, Xinzhe,Zhao, Shuang,Wang, Jianji,Hou, Chaodong
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experimental part
p. 43 - 45
(2010/03/24)
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- A direct approach to 5-hydroxybenzofurans via a platinum-catalyzed domino rearrangement/5-endo-dig cyclization reaction of quinols
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(Chemical Equation Presented) A highly efficient and atom-economical construction of 2-substituted 5-hydroxybenzofurans was accomplished by employing a platinum-catalyzed domino dienone-phenol rearrangement/5-endo-dig cyclization reaction of quinols beari
- Kim, Ikyon,Kim, Kyungsun,Choi, Jungeun
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scheme or table
p. 8492 - 8495
(2010/03/01)
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- Experimental and semiemprical studies of chemical reactivity of dialkylcadmium reagents addition to α,β-enones
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Experimental and semiempirical calculations were carried out to study the reactivity of dialkylcadmium reagents addition to α,β-enones. It was demonstrated that α,β-enone such as benzoquinone with low lying LUMO energy reacts via single electron transfer (SET) mechanism with the formation of the 1,2 or 1,4-type alkyl addition product depending on the reaction temperature and substrate structure. Site and chemoselectivity in unsymmetrical benzoquinone derivatives are determined by the stability of the cadmium coordinated semienone complex intermediates and the carbon spin densities of these reactive species respectively. On the other hand, by increasing the LUMO energy of α,β-enone system, the reaction mechanism changes from SET to polar addition affording the 1,4-type alkyl addition product. The establishment of a correlation scale between substrate LUMO energies and reaction mechanism presented in this article will be discussed.
- Ghandi, Mehdi,Shahidzadeh, Mansour
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p. 4918 - 4925
(2007/10/03)
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- Evidence for single electron transfer (SET) pathway in the reaction of primary alkylcadmium reagents with p-benzoquinone
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The reaction of primary alkylcadmium reagents with p-benzoquinone at various conditions was studied. On the basis of our results, reaction proceeds through a SET mechanism that forms loose and tight intermediates, which produce quinole (1) and substituted hydroquinone (2). In both cases, hydroquinone (3) is obtained in different yields.
- Shahidzadeh, Mansour,Ghandi, Mehdi
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p. 108 - 111
(2007/10/03)
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- A Potentially General Regiospecific Synthesis of Substituted Quinones from Dimethyl Squarate
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A potentially general regiospecific synthesis of benzo- and naphthoquinones is described.This method starts with dimethyl squarate (1) which is converted to the cyclobutenone ketal 3 upon sequential treatment with an organolithium reagent and then BF3 etherate or TFAA in THF/methanol.Treatment of these with a second lithium reagent followed by hydrolysis gives the cyclobutenones 5.Addition of an alkynyl-, alkenyl- or aryllithium agent to 5 followed by hydrolysis of the ketal linkage gives the corresponding 4-alkynyl-, 4-alkenyl- or 4-aryl-4-hydroxycyclobutenones7 - 9, and these readily rearrange to the respective quinones or hydroquinones upon thermolysis in refluxing benzene.In a similar fashion, 15 was employed as a reagent to prepare mono- and disubstituted hydroquinones and quinones.
- Gayo, Leah M.,Winters, Michael P.,Moore, Harold W.
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p. 6896 - 6899
(2007/10/02)
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