Synthesis 2007(21): 3290-3294  
DOI: 10.1055/s-2007-990828
PAPER
© Georg Thieme Verlag Stuttgart · New York

Diastereofacial-Selective Synthesis of the Trindane-Based Molecular Scaffold cis,cis,cis-2,5,8-Tribenzyltrindane-2,5,8-tricarboxylate and an Arylamine Analogue for the Construction of C 3 v -Symmetric Architectures

Heung-Jin Choi*, Jie Song, Chan Young An, Quoc-Thiet Nguyen, Hong-Seok Kim
Department of Applied Chemistry, Kyungpook National University, Daegu 702-701, South Korea
Fax: +82(53)9505582; e-Mail: choihj@knu.ac.kr;
Further Information

Publication History

Received 9 July 2007
Publication Date:
16 October 2007 (online)

Abstract

Efficient syntheses of potentially valuable C 3 v -symmetric trindane-based triester scaffolds are reported. In the synthesis of 2,5,8-tribenzyltrindane-2,5,8-tricarboxylate by the benzylation of the corresponding triester by treatment with lithium diisopropyl­amide in tetrahydrofuran, the diastereoselectivity and yield of the cis,cis,cis- and cis,trans,trans-isomers depended primarily on the reaction temperature and the amount of hexamethylphosphoramide used as additive. High diastereofacial selectivity was achieved at -90 °C in tetrahydrofuran, and the cis,cis,cis-isomer was obtained as the major product in 45% yield and in a diastereomeric ratio of 1.12. Under the same reaction conditions the 2,5,8-tris(4-bromobenzyl)trindane-2,5,8-tricarboxylate analogue was synthesized in 46% yield; it was efficiently converted into the 2,5,8-tris(4-aminobenzyl)trindane-2,5,8-tricarboxylate by palladium-catalyzed aromatic C-N bond formation by reaction with hexamethyldisilazide as nitrogen source in the presence of bis(dibenzylideneacetone)palladium with tri-tert-butylphosphine as catalyst in toluene.