Bifunctional Squaramide‐Catalyzed Asymmetric [3+2] Annluation Reactions of 2‐Isothiocyanato‐1‐indanones with 2‐Arylidene‐1,3‐indanediones

Abstract A squaramide‐catalyzed asymmetric Michael/cyclization tandem reaction between 2‐isothiocyanato‐1‐indanones and 2‐arylidene‐1,3‐indanediones was developed. Under this strategy, the corresponding chiral bispirocyclic indanone compounds containing two contiguous stereocenters were obtained under mild conditions in moderate to excellent yields (up to 99 %) and enantioselectivities (up to 98 % ee). In addition, further transformation experiments were achieved through the oxidation and methylation reactions of the product, which also confirmed the synthetic practicality of this synthetic strategy.