AbstractEfficient synthesis of optically active N‐fused 1,3‐oxazolidines containing quaternary and tertiary stereocenters was achieved via Pd‐catalyzed asymmetric (3+2) cycloadditions of sulfamate‐derived cyclic imines and vinylethylene carbonates. Using a chiral phosphoramidite ligand, the cycloadditions proceeded effectively providing sulfamidate‐fused 1,3‐oxazolidines in high yields (up to 96%) with stereoselectivities (up to 25:1 dr; >99% ee). Additionally, the scale‐up reaction and further transformations of the product were also achieved demonstrating the synthetic utility toward the construction of useful heterocycles such as chiral oxazoline bearing a quaternary stereocenter.magnified image