Gold and bifunctional thiourea catalyzed asymmetric cycloisomerization/annulation reactions of enynamides and allyl ketones: synthesis of 4,5,6,7-tetrahydrofuro[2,3-b]pyridines.

A one-pot multicatalytic cycloisomerization/annulation method using gold as a transition metal catalyst and bifunctional thiourea as an organocatalyst is developed. The gold catalyst activates the enynamide substrate to produce an azadiene intermediate, which then subsequently reacts with allyl ketones in the presence of bifunctional thiourea to afford 4,5,6,7-tetrahydrofuro[2,3-b]pyridines with excellent diastereo- and enantio-selectivities.