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Selective Host Amplification from a Dynamic Combinatorial Library of Oligoimines for the Syntheses of Different Optically Active Polyazamacrocycles
Author(s) -
GonzálezÁlvarez Almudena,
Alfonso Ignacio,
LópezOrtiz Fernando,
Aguirre Ángel,
GarcíaGranda Santiago,
Gotor Vicente
Publication year - 2004
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200300628
Subject(s) - chemistry , imine , combinatorial chemistry , polyamine , metal ions in aqueous solution , metal , stereochemistry , organic chemistry , biochemistry , catalysis
Abstract Two different macrocyclic hosts are amplified and expressed by metal guests from the same dynamic combinatorial library (DCL) of oligoimines. We studied the thermodynamic template effect and the structure of the final compounds by a combination of ESI‐MS, UV and NMR spectroscopy, and X‐ray crystallography techniques. The use of Ba II or Cd II metal salts allows the selective synthesis of dimeric [2+2] or trimeric [3+3] cyclic structures, respectively. We observed a cooperative molding effect for the Cd ion‐templated process. A study of the DCL behavior in situ demonstrated a second level of molecular diversity, based on the imine/α‐methoxyamine equilibrium. This process is probably promoted by metal ion coordination and shows an interesting diastereoselectivity in the formation of the new chiral centers. Semiempirical (PM3) theoretical calculations also support these experimental observations. Reduction of the imine bonds allows the selective preparation and isolation of each macrocyclic polyamine on a synthetic scale and in a one‐pot procedure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)