Non-Enzymatic Desymmetrization Reactions in Aqueous Media

Symmetric organic compounds are generally obtained inexpensively, and therefore they can be attractive building blocks for the total synthesis of various pharmaceuticals and natural products. The drawback is that discriminating the identical functional groups in the symmetric compounds is difficult. Water is the most environmentally benign and inexpensive solvent. However, successful organic reactions in water are rather limited due to the hydrophobicity of organic compounds in general. Therefore, desymmetrization reactions in aqueous media are expected to offer versatile strategies for the synthesis of a variety of significant organic compounds. This review focuses on the recent progress of desymmetrization reactions of symmetric organic compounds in aqueous media without utilizing enzymes.

Building Complexity and Achieving Selectivity through Catalysis – Case Studies from the Pharmaceutical Pipeline

The last decade of small-molecule process development has witnessed a trend of increasing molecular complexity for clinical candidates. The continued advance of novel catalytic methods and subsequent translation to efficient and scalable processes has enabled process chemists to overcome the challenges associated with increasing complexity. This Account highlights several examples from the process chemistry laboratories at Amgen.1 Introduction2 The Evolution of Molecular Complexity3 Catalysis as a Lever to Build Complexity4 Ru(II)-Catalyzed Dynamic Kinetic Resolution Enabling the Manufacture of AMG 2325 Application of Enzymatic Desymmetrization toward Scale-Up of the MCL-1 Inhibitor AMG 1766 Synthesis of Fucostatin 1: Catalytic Asymmetric Transfer Hydrogenation7 Manganese-Catalyzed Asymmetric Epoxidation To Prepare a Carfilzomib Intermediate8 Asymmetric Reduction Strategies: Novel Apelin Receptor Agonists and AMG 9869 Conclusions

Asymmetric Synthetic Strategies of (R)-(–)-Baclofen: An Antispastic Drug

Baclofen is an antispastic drug used as a muscle relaxant in the treatment of the paroxysmal pain of trigeminal neuralgia, spasticity of the spinal cord and cerebral origin. Baclofen resides biological activity exclusively in its (R)-(–)-enantiomer. In this review, various asymmetric synthetic strategies for (R)-(–)-baclofen are described.1 Introduction2 Resolution Synthetic Approaches2.1 Chemical Resolution2.2 Biocatalytic Resolution3 Asymmetric Desymmetrization3.1 Catalytic Enantioselective Desymmetrization3.2 Enzymatic Desymmetrization4 Chiral Auxiliary Induced Asymmetric Synthesis4.1 Asymmetric Michael Addition4.2 Asymmetric Aldol Addition4.3 Asymmetric Nucleophilic Substitution5 Asymmetric Reduction5.1 Catalytic Asymmetric Hydrogenation5.2 Bioreduction6 Catalytic Asymmetric Conjugate Addition7 Conclusion