This book explores efficient syntheses of indole alkaloids based on gold-catalyzed cascade cyclizations, presenting two strategies for total synthesis of these natural products based on gold-catalyzed reactions of conjugated diyne or ynamide.
The book first describes the total and formal synthesis of dictyodendrins A–F based on direct construction of the pyrrolo[2,3-c]carbazole core using the gold-catalyzed annulation of azido-diynes and protected pyrrole. This synthetic strategy features late-stage functionalization of the pyrrolo[2,3-c]carbazole scaffold at several positions and allows diverse access to dictyodendrins and their derivatives. Secondly, the book discusses the formal synthesis of vindorosine based on the pyrrolo[2,3-d]carbazole construction using the gold-catalyzed cascade cyclization of ynamide. Importantly, the reaction using a chiral gold complex provides the optically active pyrrolo[2,3-d]carbazole. This strategy facilitates the rapid construction of the pyrrolocarbazole core structure of aspidosperma and related alkaloids, including vindorosine.
These methodologies can accelerate the medicinal application of pyrrolocarbazole-type alkaloids and related compounds.
Author(s): Junpei Matsuoka
Series: Springer Theses
Edition: 1st ed. 2020
Publisher: Springer Nature
Year: 2020
Language: English
Pages: 94
City: Singapore
Supervisor’s Foreword
List of Publications
Acknowledgements
Contents
1 Introduction
1.1 Pyrrolocarbazoles
1.1.1 Dictyodendrins
1.1.2 Vindorosine
1.2 Gold-Catalyzed Reactions of Alkynes
1.2.1 Gold-Catalyzed Reactions of Ynamides
1.2.2 Gold-Catalyzed Cyclization of Diynes
1.2.3 Gold-Catalyzed Cyclization via Gold Carbenoid Species
1.2.4 Gold-Catalyzed Acetylenic Schmidt Reaction via Gold Carbenoid Species
References
2 Total Synthesis of Dictyodendrins by the Gold-Catalyzed Cascade Cyclization of Conjugated Diynes with Pyrroles
2.1 Experimental Section
2.1.1 General Methods
2.1.2 Preparation of the Cyclization Precursors 7
2.1.3 Gold-Catalyzed Cascade Cyclization
2.1.4 Total and Formal Synthesis of Dictyodendrins A–F
2.1.5 Preparation of Catalyst
2.1.6 Biological Evaluations and Binding Mode Analysis
References
3 Construction of the Pyrrolo[2,3-d]Carbazole Core of Spiroindoline Alkaloids by Gold-Catalyzed Cascade Cyclization of Ynamide
3.1 Experimental Section
3.1.1 General Methods
3.1.2 Preparation of the Cyclization Precursor
3.1.3 Gold-Catalyzed Cascade Cyclization
3.1.4 Formal Synthesis of Vindorosine
3.1.5 Crystallography
References
4 Conclusion
