| Abstract: | This work reports gold‐catalyzed bicyclic annulations of 2‐alkynyl‐1‐carbonylbenzenes with vinyldiazo ketones that serve as five‐atom building units. The importance of these reactions is to access 4,5‐dihydro‐benzo[g]indazoles, which form the structural cores of various bioactive molecules. According to our mechanistic analysis, we postulate initial [5+4]‐cycloadditions between benzopyrilium intermediates and vinyldiazo ketones, followed by 6‐π‐electrocyclizations to achieve the excellent stereoselectivity. |
