5470-15-5Relevant articles and documents
Mesoporous silica SBA-15 functionalized with acidic deep eutectic solvent: A highly active heterogeneous N-formylation catalyst under solvent-free conditions
Azizi, Najmedin,Edrisi, Mahtab,Abbasi, Faezeh
, (2017/10/05)
Mesoporous silica SBA-15 functionalized with N-methylpyrrolidonium-zinc chloride based deep eutectic solvent (DES) is found to be a more efficient and reusable catalyst for a convenient N-formylation of a variety of amines at room temperature. N-Formylation of primary, secondary as well as heterocyclic amines have been carried out in good to excellent yields by treatment with formic acid in low loading of DES/SBA-15 an environmentally benign catalyst for the first time. The DES/SBA-15 catalyst, which possesses both Br?nsted and Lewis acidities as well as an active SBA-15 support, makes this procedure quite simple, reusable, more convenient and practical. This catalyst was tolerant of a wide range of functional groups, and it can be reused for four runs without obvious deactivation.
Consecutive Lossen rearrangement/transamidation reaction of hydroxamic acids under catalyst- and additive-free conditions
Jia, Mengmeng,Zhang, Heng,Lin, Yongjia,Chen, Dimei,Chen, Yanmei,Xia, Yuanzhi
, p. 3615 - 3624 (2018/05/26)
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.
An efficient reduction of N-substituted carbonylimidazolides into formamides by NaBH4
Chen, Zhiyong,Cao, Yiming,Tian, Zeyu,Zhou, Xuan,Xu, Wenjin,Yang, Jia,Teng, Hanbing
, p. 2166 - 2170 (2017/05/10)
A novel, simple and versatile protocol was investigated for highly efficient synthesis of formamides through reducing N-substituted carbonylimidazolides by NaBH4 under mild reaction conditions. By this method, not only carboxylic acids or isocyanates, but also amines can readily access formamides with high yields.
