A Highly Regio- and Diastereoselective Four-Component Reaction to Construct Polycyclic Bispiroindolines from 2-Isocyanoethylindoles and Isocyanates.

A one-pot multicomponent domino reaction between 2-isocyanoethylindoles and isocyanates for the diastereoselective construction of polycyclic bispiroindolines was developed. Fused polycyclic bispiroindolines containing two contiguous spiral atoms were afforded in moderate to good yields with excellent regio- and diastereoselectivities through a four-component Ugi-type reaction (U-4CR) under mild conditions.