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Vicinal Tetraamines of Defined Geometry: Potential Scaffolds for Assembly
Author(s) -
Pitsinos Emmanuel N.,
Lehn JeanMarie,
De Cian André
Publication year - 2001
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/1522-2675(20010131)84:1<22::aid-hlca22>3.0.co;2-6
Subject(s) - chemistry , vicinal , molecule , crystallography , crystal structure , hydrate , pyran , stereochemistry , organic chemistry
The syntheses of tetraamines 10 ( Scheme 3 ) and 17 ( Scheme 4 ), which might be useful as rigid organizing scaffolds in dynamic or standard combinatorial chemistry, are described. The Diels‐Alder reaction of the electron‐rich dienophile 1,3‐diacetyl‐2,3‐dihydro‐1 H ‐imidazol‐2‐one ( 5 ) with benzo[ c ]thiophene or 2 H ‐pyran‐2‐one is the key step in their preparation. The intermediate fused cyclic diureas 9 and 16 are dimethylglycoluril analogues, and their crystal structures are examined. Diurea 9 ( Fig. 2 ) crystallizes as a hydrate and forms undulating chains through a network of H‐bonds. These chains are interconnected through H‐bonds to the H 2 O molecules. H 2 O Molecules are not incorporated in the crystal of `bis‐urea' 16 ( Fig. 3 ), the molecules of which associate through an extended three‐dimensional H‐bonding network.