Stereoselective One-Pot Synthesis of 1-Aminoindanes and 5,6-Fused Azacycles Using a Gold-Catalyzed Redox-Pinacol-Mannich-Michael Cascade

摘要

One way to improve the synthetic efficiency of the redox reaction is to couple the reduction/oxidation steps with the desired skeletal bond formations. This strategy removes the need for extra steps for the generation or protection of reactive functional groups, or for oxidation state adjustment. However, this requires that the redox precursors are more readily available than, and able to be catalytically transformed in situ into, their functional group counterparts that undergo the desired transformation. Recently, a number of gold-catalyzed redox-exchange procedures via oxygen transfer have been reported. For example, Toste and co-workers and Zhang and co-workers reported sulfoxide-mediated or amine-N-oxide-mediated redox reactions to generate carbene equivalents for sp~2 or sp~3 C-H functionalization or 1,2-pinacol shifts.