mechanochemical synthesis of amides from carboxylic acids has been developed through an in situ acid activation with 2,4,6-trichloro-1,3,5-triazine and a catalytic amount of PPh3. Under room temperature solvent-drop grinding of the reactants in the presence of an inorganic base, a variety of carboxylic acids including aromatic acids, aliphatic acids, and N-protected α-amino acids undergo amidation to afford
The catalytic role of PPh3 and its polymer bound analog was investigated in the 2,4,6-trichloro-1,3,5-triazine (TCT) mediated amidation of carboxylicacids. In the presence of inorganic bases which were inert toward TCT, carboxylicacids rapidly reacted with amines to afford amides in good to excellent yields. The described method also enabled the synthesis of optically active protected dipeptides
在2,4,6-三氯-1,3,5-三嗪(TCT)介导的羧酸酰胺化反应中,研究了PPh 3及其与聚合物结合的类似物的催化作用。在对TCT呈惰性的无机碱的存在下,羧酸与胺迅速反应,以良好或优异的收率得到酰胺。所描述的方法还能够在没有外消旋的情况下合成旋光保护的二肽。根据31 P NMR研究证实,在PPh 3催化的酸活化过程中形成了三嗪基氯化chloride 。
Pd(ii)-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates under mild conditions
作者:Mingzong Li、Cong Wang、Ping Fang、Haibo Ge
DOI:10.1039/c1cc11635e
日期:——
A novel Pd-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates has been realized under mild reaction conditions. This method provides an efficient access to N-mono- or N,N-disubstituted benzamides and benzoates.
This contribution described the first iron-catalyzed chemoselective reduction of secondary carboxamides to aldimines under hydrosilylation conditions. The reaction is catalyzed by the well defined Fe(CO)4(IMes) complex, in the presence of 2.5 equiv. of diphenylsilane under UV irradiation (350 nm) at room temperature. [IMes=1,3-bis (2,4,6-trimethylphenyl)imidazol-2-ylidene]
Carbon−Hydrogen Bond Functionalization Approach for the Synthesis of Fluorenones and <i>ortho</i>-Arylated Benzonitriles
作者:Dmitry Shabashov、Jesús R. Molina Maldonado、Olafs Daugulis
DOI:10.1021/jo801300y
日期:2008.10.3
A sequence consisting of palladium-catalyzed benzamide ortho-arylation/reaction with (CF3CO)(2)O was developed allowing a convenient one-pot synthesis of ortho-arylated benzonitriles and fluorenone derivatives. The outcome of this transformation is dependent on the amide N-alkyl substituent. Dehydration of ortho-arylated N-cyclohexyl-benzamides by (CF3CO)(2)O results in efficient production of benzonitriles. In contrast, o-arylated N-propylbenzamides are converted to fluorenone derivatives.