Mo-catalyzed regio-, diastereo-, and enantioselective allylic alkylation of 3-aryloxindoles

A highly regio-, diastereo-, and enantioselective allylic alkylation reaction mediated by a chiral molybdenum catalyst has been developed as a novel entry into synthetically versatile 3-alkyl-3-aryloxindoles. Extremely bulky nucleophiles were employed to form a quaternary center and an adjacent tertiary center asymmetrically concurrently. The regio- and diastereoselectivity of the reaction is dependent upon the steric and electronic nature of the nucleophiles to an unusual degree. A reaction mechanism based on the bonding modes of molybdenum enolate complexes was discussed.     

Total synthesis of spirotryprostatin B via diastereoselective prenylation

Spirotryprostatin B was synthesized in eight steps, utilizing an efficient palladium-catalyzed prenylation reaction to construct the quaternary C3 stereocenter. The decarboxylation-alkylation of a series of substituted beta-keto esters is described, demonstrating the broad scope of this class of pronucleophiles and allylating agents.