An enantioselective strategy for the total synthesis of (S)-tylophorine via catalytic asymmetric allylation and a one-pot DMAP-promoted isocyanate formation/Lewis acid catalyzed cyclization sequence
作者:Bo Su、Hui Zhang、Meng Deng、Qingmin Wang
DOI:10.1039/c4ob00200h
日期:——
A new asymmetric total synthesis of a phenanthroindolizidine alkaloid (S)-tylophorine is reported, which features a catalytic asymmetric allylation of aldehydes and an unexpected one-pot DMAP promoted isocyanate formation and Lewis acid catalyzed intramolecular cyclization reaction. In addition, White's direct C–H oxidation catalyst system converting monosubstituted olefins to linear allylic acetates
Total Synthesis of Phenanthroindolizidine Alkaloids by Combining Iodoaminocyclization with Free Radical Cyclization
作者:Gong-Qing Liu、Marcel Reimann、Till Opatz
DOI:10.1021/acs.joc.6b01161
日期:2016.7.15
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 chiralbuildingblock, (S)-(+)-tylophorine was also synthesized in 49% yield