Hydrosilylation-Promoted Furan Diels–Alder Cycloadditions with Stereoselectivity Controlled by the Silyl Group

Herein we describe an unprecedented B­(C6F5)3-catalyzed cascade reaction of N-allyl-N-furfurylamides involving an initial intramolecular
furan
Diels–Alder reaction and subsequent ether cleavage. The reaction
has a broad substrate scope, even tolerating a trialkyl-substituted
olefin as the dienophile, which has not previously been observed with
conventional furan Diels–Alder reactions. In addition, the
relative configuration of the product can be controlled by the choice
of the silyl group: reactions involving Et3SiH and iPr3SiH gave different diastereomers.
Control experiments and the computational studies revealed that the
steric bulk of the silyl group plays a key role in determining the
reaction pathway and thus the relative configuration of the product.