The first example of the diastereoselective construction of polysubstituted 2,3-dihydrofurans incorporating contiguous quaternary and tertiary carbon centers via a Lewis base-catalyzed one-pot cascade sequence is described. The diversity and complexity of the final products can be efficiently constructed with high diastereoselectivities via this catalytic multistep process under mild reaction conditions.

A controllable stereoselective synthesis of tetrahydropyrrolo[2,1-a]isoquinoline derivatives bearing a sulfur moiety was demonstrated with high diastereoselectivity through a catalytic intramolecular acylsulfenylation of activated alkenes. This approach involved a catalytic thia-Michael addition triggered intramolecular aldol-type tandem sequence. Both cis- and trans-products can be readily prepared in moderate to high yields with excellent diastereoselectivities in a catalytically atom-economic fashion under the optimized mild reaction conditions.