Diversity‐Orientated Stereoselective Synthesis through Pd‐Catalyzed Switchable Decarboxylative C‒N/C‒S Bond Formation in Allylic Surrogates

Switchable catalytic transformation of reactants can be a powerful approach towards diversity‐orientated synthesis from easily available molecular synthons. Herein, an endogenous ligand‐controlled, Pd‐catalyzed allylic substitution allowing for either selective C‒N or C‒S bond formation using vinylethylene carbonates and N‐sulfonylhydrazones as coupling partners has been developed. This versatile methodology provides a facile, diversicating route for the highly chemo‐ and stereoselective synthesis of functional allylic sulfones or sulfonohydrazides. The newly developed protocol features wide substrate scope (nearly 80 examples), broad functional group tolerance and potential for the late‐stage functionalization of bioactive compounds. The isolation and crystallographic analysis of a catalytically competent pi‐allyl Pd complex suggests that the pathway leading to the allylic products proceeds through a different manifold as previously proposed for the functionalization of VECs with nucleophiles.