Indoles solid-phase organic synthesis

Estep KG, Neipp CE, Stramiello LM, Stephens A, Mavis D, Allen MP. Indole resin A versatile new support for the solid-phase synthesis of organic molecules. J Org Chem 1998 63 5300-5301. 

As we will see in the Applications section to follow, solid-phase synthesis of indoles has assnmed an important role in all of synthetic organic chemistry, including Fischer... 

A number of excellent variations on the classic Fischer indolization are known that fall outside of the previous three categories. Like solid-phase synthesis, multicomponent and domino reactions are of major interest to organic chemists. Ganem reported a three-component Fischer indole variation that embraces the union of nitriles or carboxylic acids with organometaUics followed by the addition of arylhydrazine. This exquisite method is summarized in Scheme 16 [117]. In both variations, in situ formation of the requisite arylhydrazones culminates in indolization. The presence of sufficient arylhydrazine hydrochloride... 

The Cacchi synthesis and closely related indole syntheses involving the Pd-catalyzed cyclization/trapping of 2-aIkynylanilines have filled the organic literature, and three recent examples are shown in Scheme 3 (equations 1-3) [9-11]. Moreover, this chemistry has been applied to solid-phase synthesis (EUingboe [12]), 3-iodoindoles (Barluenga... 

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