Synthesis of the Indole Nucleus

Heterogeneous Catalysts for the One-Pot Synthesis of Chemicals and Fine Chemicals

“…The indole ring is an important substructure of numerous natural and pharmacologically active compounds 487 and synthesis can be performed through many methods. 488,489 Generally, the indole synthesis through the Sonogashira reaction is performed in two steps: the first one involves the Pd-Cu catalyzed Sonogashira cross-coupling between a 2-aminoaryl halide and a substituted 1-alkyne and the second step is a Cu(I) or Pd(II) catalyzed ring-closure by hydroamination/cyclization giving the indole. This step requires stronger reaction conditions (higher temperature, stronger bases) than the first step in order to achieve high conversions.…”

RhCl3·3H2O-Catalyzed Regioselective C(sp2)–H Alkoxycarbonylation: Efficient Synthesis of Indole- and Pyrrole-2-carboxylic Acid Esters

“…The indole skeleton has been recognized as a privileged structural motif in natural products, pharmaceuticals, agrochemicals, and other functional molecules . In particular, indole-2-carboxylic esters and derivatives thereof are ubiquitous structural features in many biologically active natural alkaloids and pharmaceutical agents (Scheme a) .…”