cyclization of 5‐alkenylthiazolones and ketimines that allows the assembly of three diastereoisomers through the combination of stereodivergent organocatalysis and the following diastereoselective transformation of products. A broad spectrum of pyrrolidinylspirooxindoles featuring stereochemical diversity has been synthesized through organocatalytic formal1,3‐dipolarcycloadditions with up to 98%
We report a highly chemo- and diastereoselective [3 + 2] cyclization of vinylethylene carbonates and 5-alkenyl thiazolones through palladium catalysis. The previously inert aza-thioester moiety on the thiazolone substrates is reacted selectively with the zwitterionic pi-allylpalladium species. A variety of amide monothioacetals (AMTA) with two quaternary stereocenters are facilely synthesized. An additional spirocyclic quaternary stereocenter could be further installed by Rh-catalyzed metal-carbene insertion into the C-S bond on the AMTA moiety in a highly stereoselective manner.