Asymmetric Organocatalytic Vinylogous Michael Addition Triggered Triple-Cascade Reactions Of 2-Hydroxycinnamaldehydes And Vinylogous Nucleophiles: Construction Of Benzofused Oxabicyclo[3.3.1]Nonane Scaffolds

An organocatalytic vinylogous Michael addition triggered triple-cascade reaction has been developed. 2-Hydroxycinnamaldehydes worked under iminium activation with either acyclic or cyclic ketone-derived alpha,alpha-dicyanoalkenes, yielding the benzofused oxabicyclo[3.3.1]nonanes bearing one quaternary stereocenter with excellent stereoselectivities.