Selective Preparation of Pyrrolo[2,3‐c]tetrahydroquinolines and Indolo[3,2‐c]tetrahydroquinolines through N‐Arylation/Cycloaddition/Rearrangement Annulation Reactions of Alkynyl‐Tethered Oximes with Diaryliodonium Salts

We describe a selective preparation of a variety of functionalized pyrrolo[2,3‐c]tetrahydroquinolines and indolo[3,2‐c]tetrahydroquinolines in 40‐82% and 40‐80% yields from alkynyl‐tethered oximes with diaryliodonium triflates, respectively. The one‐pot reaction underwent N‐arylation, intramolecular [3+2] cycloaddition, selective [1.3] or [3,3]‐rearrangement of N‐O bond in total three steps. Experimental studies revealed that EtOAc solvent and copper(II)‐catalyst played crucial roles on the formation of these two tetrahydroquinoline scaffolds. Moreover, these two tetrahydroquinoline scaffolds could be converted into various tetrahydroquinoline building blocks by further transformations.