A Concise Palladium-Catalyzed Carboamination Route to (±)-Tylophorine
作者:Lana M. Rossiter、Meagan L. Slater、Rachel E. Giessert、Samuel A. Sakwa、R. Jason Herr
DOI:10.1021/jo902114u
日期:2009.12.18
A total synthesis of the racemic natural product tylophorine [(±)-1] has been demonstrated using the palladium-catalyzed carboamination method developed by Wolfe and co-workers. In this case, an electron-rich aryl bromide 18 was prepared in four steps and subjected to palladium-catalyzed Wolfe carboamination conditions with olefinic carbamate 7 to provide the racemic 2-(arylmethyl)pyrrolidine (±)-19
作者:T.R. Govindachari、M.V. Lakshmikantham、K. Nagarajan、B.R. Pai
DOI:10.1016/0040-4020(58)80052-6
日期:1958.1
Tylophorine has been degraded to a compound, identified as 2:3:6:7-tetramethoxy-9-methylphenanthrene. In conjunction with other degradation results and biogenetic considerations, tylophorine is now formulated as 2:3:6:7-tetramethoxyphenanthro(9:10:6′:7′)indolizidine.
The total synthesis of alkaloids phenanthroindolizidine 1a, tylophorine 1b, and phenanthroquinolizidine 1c, has been achieved in 46%, 49%, and 42% overall yield, respectively, starting from the corresponding phenanthrene-9-carboxaldehyde. Compound exhibited potent inhibition activity in three human cancer cell lines, with IC(50) values ranging from 104 to 130 nM. The structure-activity relations of