Catalytic diastereo- and enantioselective formation of all-carbon quaternary centers: ir-catalyzed tert-(hydroxy)prenylation of alcohols and its application to modular syntheses of terpenoids

All-carbon quaternary stereocenters are ubiquitous in bioactive natural products as well as pharmaceutical molecules. However, stereoselective access of these structural motifs is still a challenge in synthetic chemistry. Therefore, a general method that can construct quaternary carbon centers diastereo- and enantioselectively is in high demand. Redox-triggered stereoselective C-C bond forming reactions via metal-catalyzed transfer hydrogenation are able to avoid usage of sensitive preformed organometallic reagents and formation of stoichiometric metal waste. Efforts have been focused on the development of efficient methods for diastereo- and enantioselective generation of quaternary centers via iridium-catalyzed tert-(hydroxy)prenylation of alcohols and aldehydes. Applying this methodology to modular syntheses of terpenoid natural products oridamycin A, triptoquinones B and C, isoiresin and andrographolide in the most concise routes is described.