Direct FeX3-Based Stereocontrolled Access to (Z)-3-Alkenyl-oxindoles from Allenols

Iron trihalides (FeCl3 and FeBr3) smoothly promote the halogenation/rearrangement of 2-indolinone-tethered allenols to efficiently afford 3-halodienyl-oxindoles with good yield and total selectivity. Also, 2-halo-1,3-dienes are synthetically interesting building blocks for the preparation of functionalized 3-alkenyl-oxindoles through a Suzuki-Miyaura reaction.