- Cobalt-Catalyzed Reductive C-O Bond Cleavage of Lignin β-O-4 Ketone Models via in Situ Generation of the Cobalt-Boryl Species
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An efficient and mild method for reductive C-O bond cleavage of lignin β-O-4 ketone models was developed to afford the corresponding ketones and phenols with PDI-CoCl2 as the precatalyst and diboron reagent as the reductant. The synthetic utility of the methodology was demonstrated by depolymerization of a polymeric model and gram-scale transformation. Mechanistic studies suggested that this transformation involves steps of carbonyl insertion, 1,2-Brook type rearrangement, β-oxygen elimination, and rate-limiting regeneration of the catalytic active Co-B species.
- Gao, Kecheng,Xu, Man,Cai, Cheng,Ding, Yanghao,Chen, Jianhui,Liu, Bosheng,Xia, Yuanzhi
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supporting information
p. 6055 - 6060
(2020/08/12)
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- Method for preparing alpha-acyloxy ketone compound
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The invention discloses a method for preparing an alpha-acyloxy ketone compound. According to the invention, simple and easily available alcohol and carboxylic acid are taken as the raw materials, under mediation of NBS(N-bromo-succinimide) and DBU(1,8-diazabicyclo(5.4.0)undec-7-alkene), the alpha-acyloxy ketone is prepared by a one-pot reaction. The method has the advantages of mild reaction condition, simple and easily available raw materials, wide substrate adaptation scope, no requirement of rigorous reaction conditions such as any metal catalyst, peroxy compounds, low or high temperature and water-free and oxygen-free conditions, metal pollution is avoided; and the method also has the advantages of stable technical condition, simple and safe operation, and easy purifying of the product.
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Paragraph 0026
(2017/04/28)
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- NBS/DBU mediated one-pot synthesis of α-acyloxyketones from benzylic secondary alcohols and carboxylic acids
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A simple and efficient one-pot NBS/DBU-mediated method has been developed for the synthesis of α-acyloxyketones from various benzylic secondary alcohols and carboxylic acids. Through this methodology, a series of α-acyloxyketones could be obtained in good to excellent yields under mild conditions. Importantly, this new reaction avoids the direct usage of toxic metal catalysts or potentially dangerous peroxide oxidants.
- Zhu, Minghui,Wei, Wei,Yang, Daoshan,Cui, Hong,Cui, Huanhuan,Sun, Xuejun,Wang, Hua
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supporting information
p. 10998 - 11001
(2016/12/06)
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- NBu4NI-catalyzed α-benzoxylation of ketones with terminal aryl alkenes
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A metal-free protocol for the α-benzoxylation of ketones has been developed by using terminal aryl alkenes as an arylcarboxy surrogate. Moderate to good yields were attained for a variety of propiophenones and acetophenones by using tetra-n-butylammonium iodide (TBAI) as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant under ambient reaction conditions. An efficient synthesis for the α-benzoxylation of aryl ketones has been developed by using terminal aryl alkenes as the arylcarboxy surrogate. The products were obtained in moderate to good yields for a broad scope of substrates. Tetra-n-butylammonium iodide (TBAI) and tert-butyl hydroperoxide (TBHP) were employed as the catalyst and oxidant, respectively.
- Mondal, Buddhadeb,Sahoo, Subas Chandra,Pan, Subhas Chandra
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p. 3135 - 3140
(2015/05/13)
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- One-pot synthesis of phenacyl esters from acetophenone, [Bmim]Br 3, and potassium salts of carboxylic acids under solvent-free conditions
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One-pot synthesis of phenacyl esters from acetophenone, [Bmim]Br3, and potassium salts of carboxylic acids under solvent-free conditions gave the corresponding phenacyl esters with excellent yields. Copyright Taylor & Francis Group, LLC.
- Le, Zhang-Gao,Xie, Zong-Bo,Xu, Jian-Ping
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experimental part
p. 743 - 747
(2009/06/28)
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- Organic Reactions in Ionic Liquids: Ionic Liquid-Accelerated Nucleophilic Substitution Reaction of α-Tosyloxyketones with Potassium Salts of Aromatic Acids
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The room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) is used as a 'green' recyclable alternative to classical molecular solvents for the nucleophilic substitution reaction of α-tosyloxy ketones with pota
- Liu, Zhi,Chen, Zhen-Chu,Zheng, Qin-Guo
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- Kinetics of the Reactions of Phenacyl Bromide and of para-Substituted Phenacyl Bromides with Benzoate and Substituted trans-Cinnamate Ions
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The second-order rate constants for the reactions of various para-substituted phenacyl bromides with benzoate ion and with several substituted trans-cinnamate ions have been measured in 90 percent acetone - 10 percent water (v/v) mixture.Electron-releasin
- Srinavasan, Chockalingam,Shunmugasundaram, Arunachalam,Arumugam, Natesan
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- Separation of Polar and Steric Effects in Reactions of ortho-Substituted Benzoate Ions with para-Substituted Phenacyl Bromides
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The second order rate constants for SN2 reactions of several ortho-substituted benzoate ions with several para-substituted phenacyl bromides have been measured in 90percent acetone - 10percent water (v/v) mixture at 35 deg C.Satisfactory correl
- Srinivasan, C.,Shunmugasundaram, A.,Roja, M.,Arumugam, N.
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p. 555 - 557
(2007/10/02)
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