10.1021/acs.orglett.9b01397.s001 Young-In Jo Young-In Jo Martin D. Burke Martin D. Burke Cheol-Hong Cheon Cheol-Hong Cheon Modular Syntheses of Phenanthro­indolizidine Natural Products American Chemical Society 2019 strategy hexahydroindolizine Phenanthro Subsequent saturation bromoaryl N alkaloids mesyl chloride Suzuki dihydroindolizidinium ring phenanthro synthesis Natural methyliminodiacetate pyridyl bromide one-pot aryl boronic acids aza-terphenyl vanadium-catalyzed oxidative electrocyclization column-separation operations iterative MIDA ortho Modular Syntheses boronate bond 2019-05-21 11:34:38 Journal contribution https://acs.figshare.com/articles/journal_contribution/Modular_Syntheses_of_Phenanthro_indolizidine_Natural_Products/8159087 A highly concise strategy for the total synthesis of phenanthro­indolizidines was developed. The one-pot iterative Suzuki–Miyaura reaction of aryl boronic acids with <i>ortho</i>-bromoaryl <i>N</i>-methyliminodiacetate (MIDA) boronate followed by a second Suzuki–Miyaura reaction with a suitable pyridyl bromide provided <i>ortho</i>-aza-terphenyls. Subsequent saturation of the triple bond, treatment with mesyl chloride, and reduction of the resulting dihydroindolizidinium ring afforded the hexahydroindolizines. A final vanadium-catalyzed oxidative electrocyclization provided the desired alkaloids in only three column-separation operations.