Highly diastereoselective three-component vinylogous Mannich reaction between isoquinolines, acyl/sulfonyl chlorides, and silyloxyfurans.

Reaction of an isoquinoline, a silyloxyfuran, and an acyl or sulfonyl chloride provides easy access to a wide variety of isoquinolinobutyrolactones with excellent yields and diastereoselectivites (R*,R* isomer), even in the case of formation of quaternary centers (i.e., R(3) or R(4) = Me). Moreover, the use of a chiral auxiliary allowed formation of a single stereoisomer in 96% yield. This represents the first examples of asymmetric vinylogous Mannich reactions on isoquinolinium salts.