Sequential Catalytic Asymmetric Heck-Iminium Ion Cyclization
A. B. Dounay, L. E. Overman*, A. D. Wrobleski
University of California, Irvine, USA
21. September 2005 (online)
This is a nice procedure for the construction of enantiopure (dihydroiminoethano)carbazoles, utilizing a sequential Heck-iminium ion cyclization scheme. A catalyst loading of 15 mol% Pd, and 45% equivalents of the Pfaltz ligand gave the cyclized product with 99% ee. The development of this transformation provides the first total synthesis of (+)-minfiensine.