Total synthesis of pyrrolo[2,3-c]quinoline alkaloid: trigonoine B

• Takashi Nishiyama,
• Erina Hamada,
• Daishi Ishii,
• Yuuto Kihara,
• Nanase Choshi,
• Natsumi Nakanishi,
• Mari Murakami,
• Kimiko Taninaka,
• Noriyuki Hatae and
• Tominari Choshi

Beilstein J. Org. Chem. 2021, 17, 730–736, doi:10.3762/bjoc.17.62

• , Yokohama University of Pharmacy, 601 Matano, Totsuka-ku, Yokohama 245-0066, Japan 10.3762/bjoc.17.62 Abstract The first total synthesis of the pyrrolo[2,3-c]quinoline alkaloid trigonoine B (1) was accomplished via a six-step sequence involving the construction of an N-substituted 4-aminopyrrolo[2,3-c

• -aminopyrroloquinolines with various biological activities. Keywords: 2-azahexatiriene system; carbodiimide; electrocyclization; pyrrolo[2,3-c]quinoline; trigonoine B; Introduction In 2011, two novel alkaloids, namely trigonoine A and B, were isolated from the leaves of Trigonostemon lii by Hao and co-workers [1]. The

• structures of the compounds were elucidated through 1D and 2D NMR spectroscopy. It was determined that trigonoine A was a β-carboline alkaloid containing a 2,8-diazabicyclo[3.3.1]nonane ring system, while trigonoine B (1) was formed by a combination of 2,3-dihydroquinolin-4-one and 3H-pyrrolo[2,3-c]quinoline