Fischer Indolisation reaction

The Fischer Indolisation Reaction occurs when the phenylhydrazone of a suitable aldehyde or ketone undergoes cyclisation with loss of ammonia, under the influence of various reagents, such as zinc chloride, ethnnolic hydrogen chloride, or acetic acid. For example, the phenylhydrazone of acetophenone (p. 257) when heated with zinc chloride gives 2 phenylindole. ... 

In a related reaction, a number of aryloic compounds, behaving as ketonic moieties in the Fischer indolisation, have been shown to afford carbazoles in the Japp-Maitland condensation. For example, when either I-naphthol, 2-naphthol, 6-alkyl-2-naphthol, ... 

There are many ingenious sophisticated variations on the reactor cells, but a simple, though not very versatile, flow cell has been described for use in a microwave heater, where the reaction solution was percolated through sand in a test tube as the equivalent of multiple microchannels. This set-up was used to carry out a Bohlmann-Rahtz pyridine synthesis and a Fischer indolisation. ... 

An asymmetric N-H insertion reaction of methyl a-diazo-ot-phenylacetate (207) to B0CNH2 (208), catalysed by the dirhodium(II) complex and phosphoric acid (203) produced 2-(tert-butoxycarbonylamino)-2-aryl-acetate (209) in high yield and high enantioselectivity (Scheme 55). Asymmetric Fischer indolisation of 4-substituted cyclohexanone-derived phenylhydrazones (210) catalysed by spirocyclic chiral phosphoric acid (212-213) gave various 3-substituted tetrahydrocarbazoles (211) in high yields (Scheme 56). ... 

---