Catalyst-controlled diastereoselective ring-opening formal [3+2]-cycloadditions of arylvinyl oxirane 2,2-diesters with cyclic N-sulfonyl imines

A diastereoselectivity-controllable formal[3+2]-cycloaddition of arylvinyl oxirane 2,2-diesters with cyclic N-sulfonyl imines is developed,affording the corresponding tricyclic oxazolidine derivatives in moderate to excellent yields with excellent diastereoselectivities in the presence of palladium(0)or scandium(III)triflate.This protocol allows selective synthesis of diastereomers of tricyclic oxazolidine derivatives under switchable and mild conditions.Further transformations of the obtained products were conducted by removing ester groups and arylvinyl moieties.