Functionalisation of the alkoxy group of alkyl aryl ethers. Demethylation, alkylthiolation and reduction of 5-methoxyindoles
摘要:
In the presence of AlX(3)-RSH three kinds of reactions may take place with 5-methoxy indoles : demethylation, alkylthiolation and reduction. The two latter reactions have never been observed to the present, with such reagents. Considerable improvement in the selective demethylation was found when PhCH(2)SH replaced EtSH previously used in such transformations. Factors leading to selective alkylthiolations or reductions are shown and mechanisms are proposed to explain these new reactions.
Aggregative activation and heterocyclic chemistry I complex bases promoted arynic cyclisation of imines or enaminoketones; regiochemical synthesis of indoles
摘要:
The complex base NaNH2-t-BuONa allowed expeditious syntheses of indoles by arynic cyclisation of imines or enaminoketones prepared from halogeno anilines and carbonyl derivatives. Unstable imines may be used without purification, complex bases being unsensitive to impurities. It is showed that this kind of reaction may be applied to mixture of substrates suitably halogenated on the benzene ring. Formation of three components aggregates is proposed to explain a number of observations.
The complex base NaNH2-tBuONa allows expeditious synthesis of indole derivatives by arynic cyclization of imines or enamines of chloroanilines. Unstable may be used without purification, complex bases being unsensitive to impurities.