Department of Chemistry, Osmania University, Hyderabad-500 007, India.
Org Biomol Chem. 2020 Apr 29;18(16):3032-3037. doi: 10.1039/d0ob00318b.
The development of site-selective C-H functionalizations/annulations is one of the most challenging practices in synthetic organic chemistry particularly for substrates bearing several similarly reactive C-H bonds. Herein, we describe catalyst and solvent controlled ortho/peri site-selective oxidative annulation of C-H bonds of N-aryl substituted quinazolin-4-amines with internal alkynes. The ortho C-H selective annulation was observed using Pd-catalyst in DMF to give indole-quinazoline derivatives, while, Ru-catalyst in PEG-400 favoured the peri C-H bond annulation exclusively to furnish pyrido-quinazoline derivatives.
芳基取代的喹唑啉-4-胺中 C-H 键的邻位/对位选择性氧化环化是合成有机化学中最具挑战性的实践之一，特别是对于含有几个类似反应性 C-H 键的底物。在此，我们描述了使用 Pd-催化剂在 DMF 中控制催化剂和溶剂的邻位/对位选择性氧化环化 N-芳基取代的喹唑啉-4-胺与内部炔烃的 C-H 键。使用 Pd-催化剂在 DMF 中观察到邻位 C-H 选择性环化，得到吲哚-喹唑啉衍生物，而 Ru-催化剂在 PEG-400 中则有利于专一地进行对位 C-H 键环化，得到吡啶并喹唑啉衍生物。
