meta- or para-position are highly effective catalysts for the amide condensation reaction in less-polar solvents. In this paper, we report that N-alkyl-4-boronopyridinium halides are more effective catalysts than the previous ones in more polar solvents. N-Alkyl-4-boronopyridinium halides are effective not only for amide condensation between equimolar mixtures of carboxylic acids and amines but also
Tetrabenzylpyrophosphate: An Efficient Catalyst for the Synthesis of Carboxamides from Carboxylic Acids and Amines
作者:Y. Thirupathi Reddy、P. Narsimha Reddy、P. Raghotham Reddy、Peter A Crooks
DOI:10.1246/cl.2008.528
日期:2008.5.5
An efficient method for the synthesis of simple and sterically hindered carboxamides from various carboxylic acids and amines using tetrabenzylpyrophosphate (TBPP) as a coupling agent in the presence of 4-(dimethylamino)pyridine (DMAP) is described. The reaction is operationally straightforward, proceeds under mild conditions at room temperature, and affords the desired product in high yield.
Novel quenchers for solution phase parallel synthesis
作者:Sham S. Nikam、Brian E. Kornberg、Stephanie E. Ault-Justus、Michael F. Rafferty
DOI:10.1016/s0040-4039(97)10781-x
日期:1998.3
The bifunctionality of amino acids can be exploited by utilizing them as quenchers in rapid solutionphaseparallelsynthesis. The amino group was used to covalently trap the excess electrophiles, whereas the carboxylic acid moiety was used to solubilize the derivatized amino acid in water. As a prototype we used potassium sarcosinate as a quencher for excess electrophiles in the acylation or sulfonation
Mild Amidation of Aldehydes with Amines Mediated by Lanthanide Catalysts
作者:SungYong Seo、Tobin J. Marks
DOI:10.1021/ol702788j
日期:2008.1.1
Catalytic amidation of aldehydes with amines is efficiently mediated by homoleptic lanthanide amido complexes, Ln[N(SiMe3)(2)](3) (Ln = La, Sm, and Y). Amidation reactivity follows the trend: La > Sm approximate to Y. These reactions proceed in high yield without added oxidants, bases, and/or heat or light, which are usually required in other catalytic amidation processes. The reaction is demonstrated with a variety of amines, with yields as high as 98% based on amine.