- Cobalt-Catalyzed Decarboxylative Methylation and Ethylation of Aliphatic N-(Acyloxy)phthalimides with Organoaluminum Reagents
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A cobalt-catalyzed decarboxylative methylation of aliphatic redox-active esters [ N-(acyloxy)phthalimides; RAEs] with trimethylaluminum under mild conditions was developed, providing a method for transforming a carboxylate group into a methyl group without redox fluctuation. Primary and secondary RAEs were both amenable substrates, whereas a tertiary RAE delivered an elimination product. Triethylaluminum was also used to deliver a decarboxylative ethylation product.
- Wang, Ze-Zhong,Wang, Guang-Zu,Zhao, Bin,Shang, Rui,Fu, Yao
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supporting information
p. 1221 - 1225
(2020/08/17)
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- Method for decarboxylation and in-situ methylation of alkyl active carboxylic ester
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The invention relates to a method for decarboxylation and in-situ methylation of alkyl active carboxylic ester. The method comprises the following step: in the presence of a cobalt catalyst, a phosphine ligand and an organic solvent, reacting alkyl active carboxylic ester with a trimethyl aluminum reagent to obtain a target methylated product. According to the provided method, trimethyl aluminum is used as a methylation reagent, so that a series of important secondary carbon and tertiary carbon centers are commercially and conveniently constructed successfully; the used carboxylate substrate is rich in source and simple to synthesize; compared with a traditional synthesis method reported before, the method avoids the use of a noble metal catalyst, and meets the requirements of green environment-friendly chemistry; the functional group compatibility is wide, the method is successfully applied to gram-scale reaction, the conversion rate is high, and the method has an important syntheticchemical value.
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Paragraph 0047-0054; 0145-0151; 0203
(2020/06/20)
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- New Sesamol Ethers as Pyrethrum Synergists
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Several new methylenedioxyphenyl (MDP) ethers were synthesised from sesamol and methoxy substituted sesamols and screened as pyrethrum synergists.In general, the synergistic activity increased with the methoxyl substituents and decreased in the corresponding alkenyl analogs.The synergistic activity of alkyl ethers was found to vary with the alkyl chain, n-propyl ethers showing the maximum.In the case of alkenyl ethers, the activity followed the order γ,γ-dimethyl allyl > β-methallyl > allyl and showed no correlation between Rm and synergistic activity.
- Devakumar, C.,Saxena, V. S.,Mukerjee, S. K.
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p. 725 - 730
(2007/10/02)
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