Water as an efficient medium for the synthesis of tetrahydro-β-carbolines via Pictet–Spengler reactions
2006; Elsevier BV; Volume: 48; Issue: 8 Linguagem: Inglês
10.1016/j.tetlet.2006.12.112
ISSN1873-3581
AutoresBiswajit Saha, Sunil Sharma, Devesh M. Sawant, Bijoy Kundu,
Tópico(s)Multicomponent Synthesis of Heterocycles
ResumoA mild and efficient protocol for the Pictet–Spengler reaction in water using an acid catalyst has been described. The condensation of tryptophan, tryptamine, and Nb-benzyl tryptophan with different aldehydes having both electron-withdrawing and -donating substituents in the presence of a catalytic amount of TFA in water furnished tetrahydro-β-carbolines in good isolated yields. A salient feature of the water mediated Pictet–Spengler reaction was the general trend observed during the condensation of Trp-OMe and aryl/aliphatic aldehydes furnishing diastereomeric mixtures with a preference for the cis-isomer.
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