We describe an efficient and straightforward synthesis of annulated pyridin-2(1H)-ones following condensation of acyl azides with internal alkynes via the ruthenium-catalyzed ortho CâH bond activation. The reaction in DCE proceeds via in situ generation of iminophosphoranes as directing group-coordination of Ru with N-atom-ortho cyclometallation-insertion of an alkyne into the RuâC bond-protonation-reductive elimination in a domino sequence. The role and stability of in situ generated iminophosphorane and ruling out the possibility for the benzamide involvement was established using 1H and 31P NMR experiments.
我们描述了一种高效且简单的合成方法,通过鲁
钛催化的邻位C–H键活化,将酰基
叠氮化物与内部
炔烃缩合,合成环状
吡啶-2(1H)-酮。该反应在DCE中进行,通过原位生成的
亚胺膦烷作为指向性基团,通过鲁与N原子之间的邻位环
金属化、
炔烃插入Ru–C键、质子化以及还原消除等一系列多米诺反应进行。我们使用¹H和³¹P NMR实验确立了原位生成的
亚胺膦烷的角色和稳定性,并排除了苯甲酰胺参与的可能性。