November 2023

In this account, we report our endeavors towards the total synthesis of the mavacuran alkaloids and some of their highly natural complex bis-indoles. Our studies started with the hemisynthesis of voacalgine A and bipleiophylline, made an excursion to a related family of monoterpene indole alkaloids (total synthesis of 17-nor-excelsinidine) and ended with the total syntheses of several mavacuran alkaloids (16-epi-pleiocarpamine, 16-hydroxymethylpleiocarpamine, taberdivarine H, normavacurine, C-mavacurine, C-profluorocurine, and C-fluorocurine) via a combination of bioinspired and non-bioinspired synthetic routes.1 Introduction2 Bioinspired Hemisynthesis of Voacalgine A and Bipleiophylline3 Total Synthesis of the Mavacuran Alkaloids4 Bioinspired Oxidative Cyclization of a Geissoschizine Ammonium Derivative to Form the N1–C16 Bond and the E Ring5 Non-Bioinspired Michael Addition to Form the C15–C20 Bond and the E Ring6 Conclusion7 Epilogue

An iridium-catalyzed ligand-controlled semi-reduction of alkynes employing H2O as the hydrogen donor, together with its application, is reported. The use of di-tert-butylphosphinous chloride is crucial for stereoselectivity toward Z-olefins, whereas the use of 2-(diphenylphosphino)benzaldehyde is crucial for stereoselectivity toward E-olefins. More than 35 alkenes were obtained in good yields and high stereoselectivities. The utility of the current method in practical applications was investigated by studying the drug effects of (E)-1,3-dimethoxy-5-styrylbenzene on nerve growth in a zebrafish model.