Ru(II)-Catalyzed Tunable Cascade Reaction via C-H/C-C Bond Cleavage.

A facile synthesis of various 3-(alkoxyalkyl)-1H-indoles from pyrazolidinones, 2-acetylenic ketones, and alkyl alcohols via C-H/C-C bond activation has been developed. The reaction proceeds smoothly under the proper reaction conditions, and preliminary mechanistic studies suggest that NaOAc is crucial for C-C bond activation. The advantages of the present method represent a redox-neutral process and exhibit excellent chemo and regioselectivity.