Synthesis of Morphinans through Anodic Aryl‐Aryl Coupling

The morphinans are an important class of structurally fascinating and physiologically important natural products as exemplified by the famous opium alkaloids of the morphine family. Although this class of secondary metabolites from the juice of the opium poppy capsule was already used for medicinal purposes thousands of years ago, chemical modifications are still being applied to the core structure today in order to achieve the most specific effect on the various receptor subtypes possible with the fewest possible side effects. The unusual architecture of the morphinan core has also proven to be a highly challenging target for total synthesis. This review highlights electrosynthetic approac…

Back Cover: A Regio- and Diastereoselective Anodic Aryl-Aryl Coupling in the Biomimetic Total Synthesis of (−)-Thebaine (Angew. Chem. Int. Ed. 34/2018)

Eine regio- und diastereoselektive anodische Aryl-Aryl-Kupplung in der biomimetischen Totalsynthese von (−)-Thebain

Synthesis of α-aminonitriles using aliphatic nitriles, α-amino acids, and hexacyanoferrate as universally applicable non-toxic cyanide sources

In cyanation reactions, the cyanide source is often directly added to the reaction mixture, which restricts the choice of conditions. The spatial separation of cyanide release and consumption offers higher flexibility instead. Such a setting was used for the cyanation of iminium ions with a variety of different easy-to-handle HCN sources such as hexacyanoferrate, acetonitrile or α-amino acids. The latter substrates were first converted to their corresponding nitriles through oxidative decarboxylation. While glycine directly furnishes HCN in the oxidation step, the aliphatic nitriles derived from α-substituted amino acids can be further converted into the corresponding cyanohydrins in an oxi…

‐Aminonitriles: From Sustainable Preparation to Applications in Natural Product Synthesis

Due to their numerous reactivity modes, α-aminonitriles represent versatile and valuable building blocks in organic total synthesis. Since their discovery by Adolph Strecker in 1850, this compound class has seen a wide dissemination in synthetic applications from laboratory to million-ton industrial scale and was extensively used in the syntheses of various classes of natural products. As these compounds provide a multitude of reactivity options, we feel that a broad overview of their multiple reaction modes may reveal less familiar opportunities for successful total synthesis planning. This personal account article will thus focus on α-aminonitriles used as key intermediates in selected na…

Rücktitelbild: Eine regio- und diastereoselektive anodische Aryl-Aryl-Kupplung in der biomimetischen Totalsynthese von (−)-Thebain (Angew. Chem. 34/2018)

A Regio- and Diastereoselective Anodic Aryl-Aryl Coupling in the Biomimetic Total Synthesis of (-)-Thebaine.

The biosynthesis of thebaine is based on the regioselective, intramolecular, oxidative coupling of (R)-reticuline. For decades, chemists have sought to mimic this coupling by using stoichiometric oxidants. However, all approaches to date have suffered from low yields or the formation of undesired regioisomers. Electrochemistry would represent a sustainable alternative in this respect but all attempts to accomplish an electrochemical synthesis of thebaine have failed so far. Herein, a regio- and diastereoselective anodic coupling of 3',4',5'-trioxygenated laudanosine derivatives is presented, which finally enables electrochemical access to (-)-thebaine.

Total synthesis and biological evaluation of seven new anti-inflammatory oxacyclododecindione-type macrolactones

Through variation of our previously published total synthesis of two highly active anti-inflammatory macrolactones from the oxacyclododecindione family (J. Tauber, M. Rohr, T. Walter, G. Erkel and T. Opatz, Org. Biomol. Chem., 2015, 13, 7813-7821), seven new representatives of this compound class were prepared. Substitution of the 14-hydroxy group in oxacyclododecindione with a methyl substituent provided a readily accessible non-natural analogue which has similar pharmacological properties to the scarcely available natural product. Since the producible amount of substance is therefore no longer restricted by low fermentation yields, extensive in vivo studies become possible for the first t…

CCDC 1831234: Experimental Crystal Structure Determination

Related Article: Alexander Lipp, Dorota Ferenc, Christoph Gütz, Mario Geffe, Nina Vierengel, Dieter Schollmeyer, Hans J. Schäfer, Siegfried R. Waldvogel, Till Opatz|2018|Angew.Chem.,Int.Ed.|57|11055|doi:10.1002/anie.201803887

CCDC 1998325: Experimental Crystal Structure Determination

Related Article: Carina Weber, Nina Vierengel, Thorsten Walter, Torsten Behrendt, Tobias Lucas, Gerhard Erkel, Till Opatz|2020|Org.Biomol.Chem.|18|5906|doi:10.1039/D0OB00958J

CCDC 1998326: Experimental Crystal Structure Determination

Related Article: Carina Weber, Nina Vierengel, Thorsten Walter, Torsten Behrendt, Tobias Lucas, Gerhard Erkel, Till Opatz|2020|Org.Biomol.Chem.|18|5906|doi:10.1039/D0OB00958J

CCDC 1998324: Experimental Crystal Structure Determination

Related Article: Carina Weber, Nina Vierengel, Thorsten Walter, Torsten Behrendt, Tobias Lucas, Gerhard Erkel, Till Opatz|2020|Org.Biomol.Chem.|18|5906|doi:10.1039/D0OB00958J

CCDC 1831233: Experimental Crystal Structure Determination

Related Article: Alexander Lipp, Dorota Ferenc, Christoph Gütz, Mario Geffe, Nina Vierengel, Dieter Schollmeyer, Hans J. Schäfer, Siegfried R. Waldvogel, Till Opatz|2018|Angew.Chem.,Int.Ed.|57|11055|doi:10.1002/anie.201803887

CCDC 1831232: Experimental Crystal Structure Determination

Related Article: Alexander Lipp, Dorota Ferenc, Christoph Gütz, Mario Geffe, Nina Vierengel, Dieter Schollmeyer, Hans J. Schäfer, Siegfried R. Waldvogel, Till Opatz|2018|Angew.Chem.,Int.Ed.|57|11055|doi:10.1002/anie.201803887

CCDC 1831236: Experimental Crystal Structure Determination

Related Article: Alexander Lipp, Dorota Ferenc, Christoph Gütz, Mario Geffe, Nina Vierengel, Dieter Schollmeyer, Hans J. Schäfer, Siegfried R. Waldvogel, Till Opatz|2018|Angew.Chem.,Int.Ed.|57|11055|doi:10.1002/anie.201803887

CCDC 1831235: Experimental Crystal Structure Determination

Related Article: Alexander Lipp, Dorota Ferenc, Christoph Gütz, Mario Geffe, Nina Vierengel, Dieter Schollmeyer, Hans J. Schäfer, Siegfried R. Waldvogel, Till Opatz|2018|Angew.Chem.,Int.Ed.|57|11055|doi:10.1002/anie.201803887