The synthesis of trisubstituted pyrrolidines and tetrahydrofurans from boronic acids,
allenes, and imines or aldehydes via a five- and a three-step protocol, respectively,
is described. The assignment of the relative stereochemistry in the pyrrolidines
and tetrahydrofurans confirmed the mechanistically significant stereochemical divergence
of the palladium-catalyzed three-component coupling reaction. The methodology is applicable
to the preparation of combinatorial libraries of pyrrolidines related to pharmaceutical
agents and bioactive natural products.
Key words
stereoselective synthesis - heterocycles - palladium - multicomponent reactions -
ring closure