Iron-Mediated Total Synthesis of 2,7-Dioxygenated Carbazole Alkaloids


  • Transition Metal Complexes in Organic Synthesis, 106. Part 105: S. Agarwal, U. Pässler, H.-J. Knölker, ARKIVOC 2013, (ii), 6.


We describe the efficient iron-mediated total synthesis of clausine O, clausine H (clauszoline-C) and anti-HIV active 7-methoxy-O-methylmukonal and clausine K (clauszoline-J). Consecutive C–C and C–N bond formations between 3-methoxy-4-methylaniline and a cyclohexadienyliumiron complex salt afforded 2,7-dimethoxy-3-methylcarbazole, which served as common intermediate en route to the four alkaloids.