Of fundamental importance in nature are substituted indoles. The thesis presents the synthesis of new indole derivatives and their functionalization to potential 5-HT6 receptor ligands. Based on our prior synthesis to indole analogues we investigated a synthetic strategy to innovative indole scaffolds via Ti- or Zn-catalyzed hydrohydrazination of terminal alkynes. We developed the pharmaceutical interesting class of 3-silyloxyindoles and their further application in several catalytic reactions. Buchwald-Hartwig amination, C-O cross-
coupling and sulfonylation were utilized and optimized.