A diversity oriented four-component approach to tetrahydro-beta-carbolines initiated by Sonogashira coupling

A consecutive four-component synthesis of highly-substituted tetrahydro-beta-carbolines 6 can be achieved by a coupling-aminatio-aza-annulation-Pictet-Spengler (CAAPS) sequence creating five new sigma-bonds and four new stereocenters in a one-pot fashion. The structures were unambiguously supported by X-ray structure analyses.