Total Synthesis of Phenanthroindolizidine Alkaloids by Combining Iodoaminocyclization with Free Radical Cyclization.
A concise and modular synthesis of phenanthroindolizidine alkaloids was achieved by combining iodoaminocylization with a free radical cyclization approach. The route described allowed the preparation of (±)-tylophorine, (±)-antofine, and (±)-deoxypergularinine in six steps. When commercially available l-prolinol was used as a chiral building block, (S)-(+)-tylophorine was also synthesized in 49% yield and >99% ee over five linear steps.
Institute of Organic Chemistry, Johannes Gutenberg University , Duesbergweg 10-14, 55128 Mainz, Germany.
Gong-Qing
GQ
Liu
Institute of Organic Chemistry, Johannes Gutenberg University , Duesbergweg 10-14, 55128 Mainz, Germany.
Marcel
M
Reimann
Institute of Organic Chemistry, Johannes Gutenberg University , Duesbergweg 10-14, 55128 Mainz, Germany.
Till
T
Opatz
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D002625:Chemistry, Organic; D003500:Cyclization; D005609:Free Radicals; D007211:Indoles; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry*; D007546:Isoquinolines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010616:Phenanthrenes / Q000737:chemistry*; D010618:Phenanthrolines / Q000138:chemical synthesis*; D011759:Pyrrolidines; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013696:Temperature
D000470:Alkaloids; D005609:Free Radicals; D007211:Indoles; D007212:Indolizines; D007546:Isoquinolines; D010616:Phenanthrenes; D010618:Phenanthrolines; D011759:Pyrrolidines; C473343:antofine; C000611652:deoxypergularinine; C521640:phenanthroindolizidine; C010509:prolinol; C004218:tylophorine