79271-23-1Relevant academic research and scientific papers
Cobalt-Catalyzed Ortho-C(sp2)-H Amidation of Benzaldehydes with Dioxazolones Using Transient Directing Groups
Huang, Jie,Ding, Jun,Ding, Tong-Mei,Zhang, Shuiyi,Wang, Yaqiu,Sha, Feng,Zhang, Shu-Yu,Wu, Xin-Yan,Li, Qiong
supporting information, p. 7342 - 7345 (2019/10/02)
An efficient and convenient cobalt-catalyzed ortho-C(sp2)-H amidation of benzaldehydes employing dioxazolones as the aminating reagent has been developed. The key feature of this protocol is the use of green and economic earth-abundant metals c
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.
One-pot synthesis of primary amines from carboxylic acids through rearrangement of in situ generated hydroxamic acid derivatives
Hoshino, Yujiro,Ohtsuka, Naoya,Okada, Takuya,Honda, Kiyoshi
, p. 5304 - 5307 (2016/11/16)
A one-pot synthesis of primary amines from carboxylic acids through a Lossen rearrangement of hydroxamic acid derivatives, which were in situ generated by the reaction of carboxylic acids with O-trimethylsilylhydroxylamine (NH2OTMS) and carbonyl diimidazole (CDI, 1.5 equiv) in dimethyl sulfoxide at room temperature, has been achieved. This one-pot method could be applied to various carboxylic acids such as aromatic, heteroaromatic, aliphatic, and optically active substrates.
A base-mediated self-propagative Lossen rearrangement of hydroxamic acids for the efficient and facile synthesis of aromatic and aliphatic primary amines
Ohtsuka, Naoya,Okuno, Moriaki,Hoshino, Yujiro,Honda, Kiyoshi
supporting information, p. 9046 - 9054 (2016/10/05)
A variety of aromatic and aliphatic hydroxamic acids were converted to the corresponding primary amines via base-mediated rearrangement. This rearrangement could proceed with less than 1 equiv. of K2CO3 in polar solvents under thermal conditions with no external reagents. This rearrangement has several features including no external activating agents needed for promoting the rearrangement, less than one equivalent of a base is sufficient for the reaction, and a clean reaction in which only carbon dioxide is produced as a by-product. A self-propagating mechanism via an isocyanate intermediate is proposed and elementary reaction steps, namely, chain propagation reactions are supported by experiments.
An efficient method for the preparation of hydroxamic acids
Gao, Xi-Ai,Wang, Xian-Xue,Yan, Hao,Li, Jian,Yan, Ru-Long,Huang, Guo-Sheng
, p. 381 - 385 (2013/05/22)
Reactions of acyl chlorides with hydroxylamine hydrochloride and NaHCO 3 generate the corresponding hydroxamic acid products in ethyl acetate and water at room temperature for 5 min. This is a simple and efficient method to synthesize a wide range of hydroxamic acids from carboxylic acids in excellent yield and high purity after simple post-treatment without chromatographic purification. In this process, the highlights are the simple separation of products and cheaply available reagents.
Base-mediated rearrangement of free aromatic hydroxamic acids (ArCO-NHOH) to anilines
Hoshino, Yujiro,Okuno, Moriaki,Kawamura, Eri,Honda, Kiyoshi,Inoue, Seiichi
supporting information; experimental part, p. 2281 - 2283 (2009/09/06)
Without using activating agents, a variety of free aromatic hydroxamic acids could be rearranged to aromatic amines in the presence of base alone. The Royal Society of Chemistry 2009.
