Construction of Seven-Membered Cycles through Base Promoted [4+3] Domino Annulation of Crotonate-derived Sulfur Ylides with Diene

A sequential [4+3] domino annulation of crotonate-derived Sulfur Ylides with Diene has been reported. With base promoted, this general method can realize the synthesis of highly functional none-fused cycles including nitrogen heterocycles and carbocycles which are widely and important in pharmaceutical molecules with excellent yield respectively, showing a great application potential. Meanwhile, this is also a supplementary to sulfur ylide chemistry as the C3 synthesizer.