33904-02-8Relevant articles and documents
Rhodium-catalyzed ortho C-H bond activation of arylamines for the synthesis of quinoline carboxylates
Gadakh, Sunita K.,Dey, Soumen,Sudalai
, p. 2969 - 2977 (2016)
The rhodium catalyzed annulation of anilines with alkynic esters allowing for the high-yield synthesis of quinoline carboxylates with excellent regioselectivity is described. This unprecedented reaction employs either formic acid as the C1 source and reductant or copper(ii) as the oxidant and is proposed to proceed via rhodacycle of in situ generated amide and enamine ester followed by ortho C-H activation of arylamines with rhodium as the catalyst.
UiO-66 as an efficient catalyst for N-formylation of amines with CO2 and dimethylamine borane as a reducing agent
Phatake, Vishal V.,Mishra, Ashish A.,Bhanage, Bhalchandra M.
supporting information, (2019/12/11)
The most effective way to make the best use of CO2, is the reductive formylation of amines, as formamides have many applications in industry. A new protocol has been developed for reductive N-formylation of amines with CO2 as a C1 carbon source and DMAB (Dimethylamine borane) as a reducing agent in the presence of Zr-containing metal–organic framework (MOF) as an efficient, heterogeneous recyclable catalyst. We used UiO-66 and UiO-66-NH2 as catalysts for N-formylation of amines and observed that both the catalyst performs equally. Therefore, we continued our studies with UiO-66 as a catalyst. The UiO-66 MOF shows good catalytic activity and affording the desired formamides in good to excellent yield. This catalytic system is very efficient for several amines including primary and secondary aliphatic cyclic and aromatic amines. Moreover, the prepared catalyst was recycled up to four recycled without a considerable decrease in catalytic activity.
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.
