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 。
3,3′-(Phenylphosphinylidene)bis[2(3<i>H</i>)-benzoxazolone] and 3,3′-(Phenylphosphinylidene)bis[2(3<i>H</i>)-benzothiazolone]. New Activating Agents
New activating agents, 3,3′-(phenylphosphinylidene)bis[2(3H)-benzoxazolone] (4) and 3,3′-(phenylphosphinylidene)bis[2(3H)-benzothiazolone] (5), were readily prepared by the reaction of phenylphosphonic dichloride (3) with 2(3H)-benzoxazolone (1) and 2(3H)-benzothiazolone (2) respectively in the presence of triethylamine at room temperature. The new activating agents 4 and 5 were found to be useful
Diphenyl (2,3-Dihydro-2-thioxo-3-benzoxazolyl)phosphonate: A New, Reactive Condensing Agent for the Synthesis of Amides, Esters, Peptides, and β-Lactams via Condensation
作者:Mitsuru Ueda、Hideharu Mori
DOI:10.1246/bcsj.65.1636
日期:1992.6
Diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (1) prepared from 2-benzoxazolethiol and diphenyl phosphorochloridate was proved to be a very useful condensing agent. A variety of amides, esters, and dipeptides were obtained in excellent yields. Furthermore, this reagent was successfully applied to the synthesis of β-lactams from β-amino acids.