- Copper-catalyzed meta-selective arylation of phenol derivatives: An easy access to m-aryl phenols
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Achieving selective meta-functionalization of phenols is a significant challenge. Accessing such compounds generally needs elevated temperature or incorporation of complex templates. Here, we report a general approach to achieve meta-arylated phenols with a simple and common directing group. This coppercatalyzed protocol proceeds with complete meta-selectivity and tolerates a variety of functional groups in both coupling partners. Computational studies have revealed that the reaction proceeded via a Heck-like pathway.
- Maraswami, Manikantha,Hirao, Hajime,Loh, Teck-Peng
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p. 2302 - 2309
(2021/02/20)
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- Palladium-Catalyzed Reductive [5+1] Cycloaddition of 3-Acetoxy-1,4-enynes with CO: Access to Phenols Enabled by Hydrosilanes
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A new palladium-catalyzed reductive [5+1] cycloaddition of 3-acetoxy-1,4-enynes with CO, enabled by hydrosilanes, has been developed for delivering valuable functionalized phenols. This methodology employs hydrosilanes as the external reagent to facilitate the [5+1] carbonylative benzannulation. The reaction is a conceptually and mechanistically novel carbonylative cycloaddition route for the construction of substituted phenols, through the formation of four new chemical bonds, with excellent functional-group tolerance.
- Li, Jin-Heng,Luo, Shenglian,Song, Ren-Jie,Wu, Li-Jun
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supporting information
p. 13308 - 13312
(2018/09/21)
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- P(NMe2)3-promoted ortho-selective arylation of phenols with diaryliodonium triflates via rhodium catalysis
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Rh-catalyzed ortho-selective arylation of free phenol with diaryliodonium triflates to widely existed phenol-containing biaryls have been developed. The use of P(NMe2)3, tBuOLi and CH3CN proved to be critical for the ortho-selectivity of this reaction.
- Liu, Qi-Sheng,Wang, De-Yin,Yang, Jin-Fei,Ma, Zhong-Yi,Ye, Mengchun
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supporting information
p. 3591 - 3595
(2017/06/13)
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- Stoichiometric to catalytic reactivity of the aryl cycloaurated species with arylboronic acids: Insight into the mechanism of gold-catalyzed oxidative C(sp2)-H arylation
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Based on the well-defined five-membered aryl gold(iii) complexes, [Au(tpy)X2] (3a and 3b) and [AuBr(Ph)(tpy)] (7), as well as the aryl gold(iii) complex [AuCl2(Ph)(tpy)] (8) (tpy = 2-(o-tolyl)pyridine) as reliable models, we present a detailed study of the mechanism for gold(iii)-catalyzed oxidative cross-coupling reactions between cycloaurable arenes and arylboronic acids. Here we report the direct evidence for a mechanistic proposal including arene C-H activation, transmetallation and biaryl reductive elimination. The chelation-assisted C-H activation strategy has been used for the development of the gold(iii)-catalyzed C-H bond arylation of arenes with aryl reagents to forge extended π-conjugated systems. This journal is
- Wu, Qian,Du, Chenglong,Huang, Yumin,Liu, Xingyan,Long, Zhen,Song, Feijie,You, Jingsong
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p. 288 - 293
(2015/02/19)
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- P-directed borylation of phenols
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Internal borylation occurs upon activation of aryl di-isopropylphosphinite boranes with HNTf2 to give heterocyclic intermediates that can be reductively quenched to afford 6 or treated with KHF2 to give the phenolic potassium aryl trifluoroborate salts 10. The latter salts are useful for Pd-catalyzed coupling with aryl iodides under Molander conditions, provided that precautions are taken to remove the KNTf2 byproduct from the preceding KHF2 step.
- Cazorla, Clément,De Vries, Timothy S.,Vedejs, Edwin
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p. 984 - 987
(2013/04/10)
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- HYDROCARBON RECOVERY FROM SULFONES FORMED BY OXIDATIVE DESULFURIZATION PROCESS
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The process provided herein is concerned with recovery of hydrocarbons from sulfones using an individual alkali and alkaline-earthy base and a mixture of thereof. As the starting materials are sulfones generated by ODS and commercially inexpensive alkali and alkaline-earth bases, the cost and ecological impact of solid waste disposal is minimized.
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Page/Page column 17-18
(2011/06/11)
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- Synthesis of substituted phenols by using the ring-closing metathesis/isoaromatization approach
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Ring-closing olefin metathesis (RCM) of 4-methylene-1,7-octadien-3-ones 2, followed by isomerization of the carbon-carbon double bond of 6-methylene-2-cyclohexenones 3 from exo to endo, produced various phenols 4. As an application of the method, the RCM/
- Yoshida, Kazuhiro,Narui, Rintaro,Imamoto, Tsuneo
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experimental part
p. 9706 - 9713
(2009/10/02)
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- Ruthenium-catalyzed rearrangement of cis-1-ethynyl-2-vinyloxiranes to substituted phenols
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Catalytic cyclization of cis-1-ethynyl-2-vinyloxiranes was implemented with TpRuPPh3(CH3CN)2PF6 catalyst (10 mol%), to give 2,6-disubstituted phenols in reasonable yields. Under similar conditions, 1,1,2,2-tetrasubstituted oxirane gave the 2,3,6-trisubstituted phenol with skeleton reorganization. On the basis of 2H- and l3C-labeling results, we propose that the reaction mechanism involves electrocyclization of ruthenium-vinylidene intermediate with cleavage of the carbon-oxygen bond of the epoxide. Georg Thieme Verlag Stuttgart.
- Maddirala, Shambabu Joseph,Odedra, Arjan,Taduri, Bhanu Pratap,Liu, Rai-Shung
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p. 1173 - 1176
(2007/10/03)
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- Suzuki-Miyaura cross-coupling reaction catalyzed by Pd/MgLa mixed oxide
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A new, reusable Pd/MgLa mixed oxide catalyst has been applied successfully in the Suzuki-Miyaura carbon-carbon cross-coupling reaction of aryl halides as well as benzylic bromide with boronic acids in ethanol. The catalyst is air stable, can be stored and handled under an ambient atmosphere and after the reaction it can be recovered by simple filtration and reused without significant loss of activity. The Royal Society of Chemistry 2005.
- Cwik, Agnieszka,Hell, Zoltan,Figueras, Francois
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p. 4307 - 4309
(2007/10/03)
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- Efficient synthesis of substituted biaryl anilines and biaryl phenols via a Suzuki cross-coupling reaction
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An efficient synthesis of biaryl building blocks with multiple point diversities via a Suzuki cross-coupling reaction using a commercially available preformed Pd catalyst 1 was reported. Substituted biaryl anilines and phenols were obtained in one step from commercially available aryl halides.
- Liu, Bin,Moffett, Kristofer K.,Joseph, Rhoda W.,Dorsey, Bruce D.
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p. 1779 - 1782
(2007/10/03)
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- Rhodium-HMPT-catalyzed direct ortho arylation of phenols with aryl bromides
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Direct ortho arylation of phenols with aryl bromides catalyzed by a rhodium complex and hexamethylphosphorous triamide (HMPT) have been developed. A plausible reaction mechanism involving in situ generation of arylphosphites from phenols and HMPT, phosphorus-directed ortho metalation, and transesterification of the arylated arylphosphites with the substrate phenols is proposed.
- Oi, Shuichi,Watanabe, Shun-Ichiro,Fukita, Susumu,Inoue, Yoshio
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p. 8665 - 8668
(2007/10/03)
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- Preparation of diphenolics
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A process for the production of diphenolic compounds having a divalent bridge. A first disubstituted phenol is reacted with an aldehyde in the presence of a secondary amine and excess alcohol to form an ether intermediate. The ether intermediate is reacted with a phenol having an open ortho or para position to form a diphenolic.
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- Preparation of ortho-alkylated phenols
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There are provided alkylation catalysts comprising magnesium oxide mixed with and bonded by manganese oxides. These are used in processes for the vapor phase ortho-alkylation of phenols with an alcohol. The present catalysts are advantageous in that they provide a substantially increased total useful life, a reduced induction period for maximum reaction selectivity, elimination of catalyst losses in comparison with the powders or weakly sintered composites of the prior art and increased selectivity for ortho-substitution. Treatment of the new catalysts with methanol vapor before use enhances their activity in converting phenols to 2,6-xylenol and results in a significant increase in production rate.
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