Study of the cis to trans isomerization of 1-phenyl-2,3-disubstituted tetrahydro-beta-carbolines at C(1). Evidence for the carbocation-mediated mechanism.

ABSTRACT: The present study was undertaken to shed light on the mechanism of the epimerization of cis-1,2,3-trisubstituted tetrahydro-beta-carbolines into the trans isomers via a potential carbocationic intermediate at C(1). In order to study the pathway involved in C(1)-N(2) bond cleavage, the electronic character of the carbon atom at C-1 was altered by substitution of electron-rich and electron-poor phenyl rings at this position. This provided direct evidence of the effects of charge at the proposed site of the carbocationic intermediate. In this regard, a diverse set of 1-(phenyl substituted)-2-benzyl-3-ethoxycarbonyl-1,2,3,4-tetrahydro-beta-carbolines has been synthesized via the Pictet-Spengler reaction by condensation of l-tryptophan derivatives with electron-poor and electron-rich aromatic a

SUBMITTER: Kumpaty HJ 

PROVIDER: S-EPMC2758420 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature