- Consecutive Lossen rearrangement/transamidation reaction of hydroxamic acids under catalyst- and additive-free conditions
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The Lossen rearrangement is a classic process for transforming activated hydroxamic acids into isocyanate under basic or thermal conditions. In the current report we disclosed a consecutive Lossen rearrangement/transamidation reaction in which unactivated hydroxamic acids were converted into N-substituted formamides in a one-pot manner under catalyst- and additive-free conditions. One feature of this novel transformation is that the formamide plays triple roles in the reaction by acting as a readily available solvent, a promoter for additive-free Lossen rearrangement, and a source of the formyl group in the final products. Acyl groups other than formyl could also be introduced into the product when changing the solvent to other low molecular weight aliphatic amide derivatives. The solvent-promoted Lossen rearrangement was better understood by DFT calculations, and the intermediacy of isocyanate and amine was supported well by experiments, in which the desired products were obtained in excellent yields under similar conditions. Not only monosubstituted formamides were synthesized from hydroxamic acids, but also N,N-disubstituted formamides were obtained when secondary amines were used as precursors.
- Jia, Mengmeng,Zhang, Heng,Lin, Yongjia,Chen, Dimei,Chen, Yanmei,Xia, Yuanzhi
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p. 3615 - 3624
(2018/05/26)
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- Photoinduced Oxidative Formylation of N,N-Dimethylanilines with Molecular Oxygen without External Photocatalyst
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A photoinduced oxidative formylation of N,N-dimethylanilines with molecular oxygen in the absence of an external photocatalyst was developed and provided the corresponding formamides in good yields under mild reaction conditions. Investigations indicated that both the starting material and product act as photosensitizers and that 1O2 coexists with O2?- during the reaction through energy transfer and single electron transfer process.
- Yang, Shuai,Li, Pinhua,Wang, Zhihui,Wang, Lei
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supporting information
p. 3386 - 3389
(2017/07/15)
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- Novel method for synthesizing N-substitute amide derivative
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The invention discloses a novel method for synthesizing an N-substitute amide derivative. The novel method is characterized by comprising the steps that at the air atmosphere, no catalyst or alkali or other any additives are added, an organic amine compound shown in a formula (I) is adopted as a reaction substrate, a solvent shown in a formula (II) is adopted as an acylation reagent, an acylation reaction is performed under the reaction temperature of 120-150 DEG C to generate the N-substitute amide derivative shown in a formula (III), and the equation is shown in the description. The novel method has the advantages that environmental protection is achieved, and post-treatment and product separation are easy; the range of the substrate is wide, and the substrate can be primary amine and can also be secondary amine; the solvent can be amide and can also be carboxylic acid, and the solvent can be adopted as the acylation reagent to participate in the reaction; the reaction efficiency is high, and the majority of reactions can reach the quantified yield; water and air have no effect on the reaction, inert gas shielding is not needed, and operation is easy.
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Paragraph 0035; 0036; 0037; 0038; 0039; 0040-0041; 0113-0115
(2017/09/02)
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