Procter Richard J, Alamillo-Ferrer Carla, Shabbir Usman, Britton Phyllida, Bučar Dejan-Krešimir, Dumon Alexandre S, Rzepa Henry S, Burés Jordi, Whiting Andrew, Sheppard Tom D
Department of Chemistry, Christopher Ingold Laboratories, University College London 20 Gordon St London WC1H 0AJ UK
Department of Chemistry, The University of Manchester Manchester M13 9PL UK
Chem Sci. 2025 Feb 4;16(11):4718-4724. doi: 10.1039/d4sc07744j. eCollection 2025 Mar 12.
The catalytic activity of different classes of boron catalysts was studied in amidation reactions with 4-phenylbutylamine/benzoic acid, and with 2-aminopyridine/phenylacetic acid. Whilst a simple boronic acid catalyst showed high catalytic activity with the former substrates, it was completely inactive in the latter reaction. In contrast, a borate ester catalyst was able to mediate the amidation of both substrate pairs with moderate activity. By screening a range of borate esters we were able to identify a novel borate catalyst that shows high reactivity with a range of challenging carboxylic acids/amine pairs, enabling catalystic amidation reactions to be achieved effectively with these industrially relevant compounds. The reactions can be performed on multigram scale with high levels of efficiency, and catalyst generation from commercially available reagents renders the process readily accessible for everyday laboratory use. Further experiments showed that the deactivating effect of 2-aminopyridine on boronic acid catalysts was due to its ability to stabilise catalytically inactive boroxines.
研究了不同种类的硼催化剂在与4-苯基丁胺/苯甲酸以及2-氨基吡啶/苯乙酸的酰胺化反应中的催化活性。虽然一种简单的硼酸催化剂对前一种底物显示出高催化活性，但在后者反应中却完全没有活性。相比之下，硼酸酯催化剂能够以中等活性介导这两组底物的酰胺化反应。通过筛选一系列硼酸酯，我们能够鉴定出一种新型硼酸催化剂，它对一系列具有挑战性的羧酸/胺对显示出高反应活性，从而能够有效地实现这些与工业相关化合物的催化酰胺化反应。这些反应可以在多克规模上高效进行，并且由市售试剂生成催化剂使得该过程便于日常实验室使用。进一步的实验表明，2-氨基吡啶对硼酸催化剂的失活作用是由于其能够稳定催化无活性的硼氧环。
