Organocatalytic Highly Enantioselective Substitution of 3-(1-Tosylalkyl)indoles with Oxindoles Enables the First Total Synthesis of (+)-Trigolutes B.

A highly enantioselective organocatalytic substitution of 3-(1-tosylalkyl)indoles with oxindoles has been established by using chiral bifunctional organocatalysts, providing an efficient entry to multiply functionalized 3,3'-disubstituted oxindoles, and was exploited as the key step to enable the first asymmetric total synthesis of optically pure (+)-trigolutes B to be accomplished in a concise manner, within seven steps with an 18% overall yield.

Chiral gold complex-catalyzed hetero-Diels-Alder reaction of diazenes: highly enantioselective and general for dienes.

A chiral gold(I) complex-catalyzed highly regio- and enantioselective azo hetero-Diels-Alder reaction has been developed. The chiral gold(I) complex acting as a Lewis acid exhibits high efficiency in the activation of urea-based diazene dienophiles. Moreover, this chiral gold catalyst also rendered a cascade intramolecular enyne cycloisomerization/asymmetric azo-HDA reaction.