Substrate‐Controlled Pd‐Catalyzed Divergent Decarboxylative Cycloaddition of Vinyloxazolidine‐2,4‐Diones with Azadienes for the Construction of Spirocycles and Medium‐Sized Heterocycles

Comprehensive Summary Herein, we report a substrate‐controlled palladium‐catalyzed divergent decarboxylative cycloaddition of vinyloxazolidine‐2,4‐diones with azadienes. The reaction of benzofuran‐derived azadienes undergoes a decarboxylative (3+2) cycloaddition process to access spiro[benzofuran‐butyrolactam] derivatives in good yields with acceptable diastereoselectivities. In contrast, the reaction of benzothiophene‐based azadienes proceeds a decarboxylative (5+4) cycloaddition pathway to give benzothieno[1,2‐ d ]diazonin‐5‐ones in moderate to high yields. Gram‐scale synthesis and further transformations demonstrated the potential synthetic utility of the developed protocol.