Enantioselective Syntheses of Yohimbine Alkaloids: Proving Grounds for New Catalytic Transformations

The total synthesis of bioactive alkaloids is an enduring challenge and an indication of the state of the art of chemical synthesis. With the explosion of catalytic asymmetric methods over the past three decades, these compelling targets have been fertile proving grounds for enantioselective bond forming transformations. These activities are summarized herein both to highlight the power and versatility of these methods and to instill future inspiration for new syntheses of these privileged natural products. 1 Introduction 2 Monoterpenoid Indole Alkaloids 2.1 Corynanthe-Type MIAs 3 Biosynthesis 4 Biological Activity 5 Scope 6 Strategies in Yohimbine Alkaloid Synthesis 6.1 Momoses Formal Synthesis of (+)-Yohimbine 6.2 Jacobsens Synthesis of (+)-Yohimbine 6.3 Hiemstras Synthesis of (+)-Yohimbine 6.4 Qins Synthesis of (-)-Yohimbine 6.5 Tans Synthesis of (+)-Rauwolscine 6.6 Jacobsens Synthesis of (+)-Reserpine 6.7 Chens Synthesis of (+)-Reserpine 6.8 Rivas Synthesis of (-)-Alloyohimbane 6.9 Katsukis Synthesis of (-)-Alloyohimbane 6.10 Ghosh's Synthesis of (-)-Yohimbane and (-)-Alloyohimbane 6.11 Hongs Synthesis of (-)-Yohimbane 6.12 Gellmans Synthesis of (-)-Yohimbane 6.13 Scheidt's Synthesis of (-)-Rauwolscine and (-)-Alloyohimbane 7 Conclusion.