85455-66-9Relevant articles and documents
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Cesium Carbonate Catalyzed Esterification of N-Benzyl- N-Boc-amides under Ambient Conditions
Ye, Danfeng,Liu, Zhiyuan,Chen, Hao,Sessler, Jonathan L.,Lei, Chuanhu
supporting information, p. 6888 - 6892 (2019/09/07)
We report a general activated amide to ester transformation catalyzed by Cs2CO3. Using this approach, esterification proceeds under relatively mild conditions and without the need for a transition metal catalyst. This method exhibits broad substrate scope and represents a practical alternative to existing esterification strategies. The synthetic utility of this protocol is demonstrated via the facile synthesis of crown ether derivatives and the late-stage modification of a representative natural product and several sugars in reasonable yields.
Fluoride-Catalyzed Esterification of Amides
Wu, Hongxiang,Guo, Weijie,Daniel, Stelck,Li, Yue,Liu, Chao,Zeng, Zhuo
, p. 3444 - 3447 (2018/02/21)
In recent years, it has been demonstrated that amide carbon–nitrogen bonds can be activated and selectively cleaved using transition metal catalysts. However, these methodologies have been restricted to specific amides; a one-to-one relationship exists between the catalytic system and the amides and also uses large amounts of transition-metal catalysts and ligands. Hence, we now report a general strategy for esterification of common amides using fluoride as a catalyst. This method shows high functional group tolerance, and notably it requires only a slight excess of the alcohol nucleophile, which is a rare case in transition-metal-free amide transformations. Moreover, this approach may provide a new understanding for further studies on esterification of amides and is expected to stimulate the development of alternative methods for direct functionalization of amides.
