KMnO4-mediated oxidative C N bond cleavage of tertiary amines: Synthesis of amides and sulfonamides
作者:Zhang Zhang、Yong-Hong Liu、Xi Zhang、Xi-Cun Wang
DOI:10.1016/j.tet.2019.03.047
日期:2019.5
KMnO4-mediated oxidative CN bond cleavage of tertiaryamines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.
Conversion of amides to esters by the nickel-catalysed activation of amide C–N bonds
作者:Liana Hie、Noah F. Fine Nathel、Tejas K. Shah、Emma L. Baker、Xin Hong、Yun-Fang Yang、Peng Liu、K. N. Houk、Neil K. Garg
DOI:10.1038/nature14615
日期:2015.8
Although enzymes are able to cleave amide bonds in nature, it is difficult to selectively break the carbonânitrogen bond of an amide using synthetic chemistry; now the activation and cleavage of these bonds using nickel catalysts is used to convert amides to esters. Although enzymes are able to cleave amide bonds in nature, it is difficult to selectively break the carbonânitrogen bond of an amide using synthetic chemistry. In this paper the authors demonstrate that amide CâN bonds can be activated and cleaved using nickel catalysts. They used this methodology to convert amides to esters, which is a challenging and underdeveloped transformation. Amides are common functional groups that have been studied for more than a century1. They are the key building blocks of proteins and are present in a broad range of other natural and synthetic compounds. Amides are known to be poor electrophiles, which is typically attributed to the resonance stability of the amide bond1,2. Although amides can readily be cleaved by enzymes such as proteases3, it is difficult to selectively break the carbonânitrogen bond of an amide using synthetic chemistry. Here we demonstrate that amide carbonânitrogen bonds can be activated and cleaved using nickel catalysts. We use this methodology to convert amides to esters, which is a challenging and underdeveloped transformation. The reaction methodology proceeds under exceptionally mild reaction conditions, and avoids the use of a large excess of an alcohol nucleophile. Density functional theory calculations provide insight into the thermodynamics and catalytic cycle of the amide-to-ester transformation. Our results provide a way to harness amide functional groups as synthetic building blocks and are expected to lead to the further use of amides in the construction of carbonâheteroatom or carbonâcarbon bonds using non-precious-metal catalysis.
A novel and efficient palladium-catalyzed aminocarbonylation of aryliodides with amides and N-alkyl anilines has been developed. The reaction tolerates a wide range of functional groups and is a reliable method for the rapid synthesis of a variety of valuable imides and tertiary benzanilides under an atmospheric pressure of CO.
Facile amidation of esters with aromatic amines promoted by lanthanide tris (amide) complexes
作者:Zhao Li、Chenjun Guo、Jue Chen、Yingming Yao、Yunjie Luo
DOI:10.1002/aoc.5517
日期:2020.4
The development of catalysts capable of catalyzing amidation of esters with amines to construct amides under mild conditions is of great importance. Compared to aliphatic amines, the direct catalytic amidation of esters with less nucleophilic aromatic amines is rather difficult. Employing simple lanthanide tris (amide) complexes Ln[N (SiMe3)2]3(μ‐Cl)Li (THF)3 as the catalysts, it was found a broad