Indole aldol-like reactions

Oxindole exists as the carbonyl-tautomer, the hydroxy 1-tautomer ( 2-hydroxyindole ) being undetectable. There is nothing remarkable about the reactions of oxindole for the most part it is a typical 5-membered lactam, except that deprotonation at the p-carbon (pA a 18) occurs more readily than with simple amides, because the resulting anion is stabilised by an aromatic indole resonance contributor. Such anions will react with electrophiles like alkyl halides and aldehydes at the p-carbon, the last with dehydration and the production of aldol condensation products. Oxindoles can be oxidised to isatins (20.13.3) via easy 3,3-dibromination, then hydrolysis. Bromination of oxindole with A -bromosuccinimide gives... 

The above solid catalysts were used successfully to catalyze various reactions, like the Suzuki-Miyura reaction [15], such as aminocarbonylation, amidatimi, and the Heck reactions [16]. Polymers containing scandium trillate, ruthenium, platinum, or gold were prepared to perform Mukayama aldol, alcohol, and sulfide oxidation, hydrogenatirMi, and indole syntheses [17]. 

Interest in the synthesis of the mitomycins has resulted in a variety of procedures for the preparation of pyrrolo-indoles and related structures. Now Ban and his colleagues have reported a biomimetic route to the mitosane skeleton which involves a novel retro-aldol type of ring-opening reaction followed by a trans-annular cyclization (Scheme 102). A mitosane-like compound is available via... 

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