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Sterically Hindered Cyclic Diynes − Syntheses and Structures

✍ Scribed by Carsten Schaefer; Rolf Gleiter; Frank Rominger

Book ID
102176762
Publisher
John Wiley and Sons
Year
2003
Tongue
English
Weight
272 KB
Volume
2003
Category
Article
ISSN
1434-193X

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✦ Synopsis

Abstract

The synthesis of three 14‐membered ring systems 8a−8c with the 1,3,8,10‐tetraoxa‐2,9‐disilacyclotetradeca‐5,12‐diyne skeleton is described. In all three ring systems the α‐positions are substituted with gem‐dimethyl and/or gem‐diphenyl groups. Structural investigations on 8a and 8c reveal a chair like conformation of the central ring with parallel alkyne units. For 8b the voluminous phenyl groups cause a twist‐chair and a twist‐boat conformation. Columnar structures were encountered for 8a in the solid state. Reactions with octacarbonyldicobalt yield for 8a mono‐ and biscomplexation (12, 13). For 8b only the mono complexation product 14 was isolated. For 8c the bis(hexacarbonyldicobalt) complex 15 was obtained. X‐ray investigations revealed columnar structures in the solid state for 12, 13, and 15. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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