Comprehensive Summary Spiroketals have gathered considerable attention owing to their prevalence in ligands, pharmaceuticals, and natural products. Their three‐dimensional complexity often imparts desirable biological activity. Nevertheless, enantioselective synthesis of spiroketals still represents considerable challenges. Herein, we report a Pd/PC‐Phos‐catalyzed enantioselective nucleophilic dearomatization of furfural N ‐sulfonylhydrazones with readily available aryl halides. Up to 96.5 : 3.5 er , 99/1 Z / E and 73% yield have been achieved. Moreover, the reaction exhibits broad substrate compatibility, good functional group tolerance, easy scalability and versatile product functionalization. This protocol enables the synthesis of chiral spiroketals in high enantioselectivity and Z / E selectivity that have limited previous synthetic access. In addition, the origins of enantioselectivity were further rationalized using density functional theory calculations. The enantio‐determining step is speculated to be the carbenation process.
Wang et al. (Mon,) studied this question.