Polycyclic indole moieties are often part of bioactive natural or synthetic products, however traditionally have to be synthesized over several steps involving time consuming sequential multi-step syntheses. We herein communicate an efficient and flexible 2-step procedure to complex multicyclic indole alkaloid-type compounds involving Ugi MCR and Pictet-Spenglerreaction.
The first catalytic enantioselective [5+1] cycloaddition reactions of C,N-cyclicazomethineimines with isocyanides are reported herein. The method displays a broad substrate scope and atom-economy. A series of chiral tetrahydroisoquinoline containing indole skeletons were obtained in up to 90% yield with 95% ee under mild reaction conditions. A possible catalytic model was also proposed.
Efficient and Diverse Synthesis of Indole Derivatives
作者:Haixia Liu、Alexander Dömling
DOI:10.1021/jo900986z
日期:2009.9.4
A convergent 2-step procedure toward an array of indole derivatives involving an Ugi reaction and a Pictet-Spengler reaction is described. The reactions are versatile regarding different starting materials. Hexacyclic 24 can be produced with unprecedented complexity.