A method for the HMPA (hexamethylphosphoric triamide)-catalyzed metal-free transfer hydrogenation of pyridines has been developed. The functional group tolerance of the existing reaction conditions provides easy access to various piperidines with ester or ketone groups at the C-3 site. The suitability of this method for the reduction of other N-heteroarenes has also been demonstrated. Thirty-three examples of different substrates have been reduced to designed products with 45–96% yields.
已经开发出一种六甲基磷酰三胺(HMPA)催化的无金属转移氢化吡啶的方法。现有反应条件下的官能团耐受性使得容易获得C-3位点带有酯基或酮基的各种哌啶。还证明了这种方法适用于还原其他N-杂芳烃。已经有33个不同底物的例子被还原为设计的产品,产率为45-96%。