Asymmetric and switchable divergent multicomponent reactions involving distinct alkynes via palladium catalysis

Asymmetric multicomponent reactions represent an efficient and economic strategy for the construction of complicated structures, and those involving two different alkynes have been rarely explored, probably due to the challenges in sequence control and chemo-, regio-, and stereoselectivity. Here, we disclosed an asymmetric multicomponent cascade vinylogous addition/Sonogashira reaction between 1,3-enynes, N-sulfonylimines, and terminal alkynes catalyzed by Pd(0), which consecutively served as a π-Lewis base catalyst and a traditional coupling catalyst. High selectivity has been achieved; moreover, the cascade reaction with a switchable hydroamination process was realized in a one-pot or stepwise manner by slightly tuning the catalytic conditions, thus furnishing enantioenriched N-heterocycles with an exocyclic double bond in either E or Z configuration stereodivergently. This work provided rapid access to a full set of stereoisomers possessing a stereogenic center and a trisubstituted double bond, and it could arouse more interest in palladium catalysis and asymmetric multicomponent reaction.