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

摘要

Herein we describe an unprecedented B-(C_6F_5)_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 Et_3SiH and 'Pr_3SiH 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.