Synthesis 2001(9): 1368-1376
DOI: 10.1055/s-2001-15224
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Aryl-Terminated Polyenaldehydes and Polyenetriethoxysilanes for Preparation of Self-Assembled Monolayers on Silicon Surfaces

Franz Effenberger*, Markus Wezstein
Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
Fax: +49(711)6854269; e-Mail: franz.effenberger@po.uni-stuttgart.de;
Further Information

Publication History

Received 12 January 2001
Publication Date:
29 September 2004 (online)

Abstract

The synthesis of α,ω-terminally functionalized polyenes with arenes or hetarenes at one end and either an aldehyde or a triethoxysilyl function at the other end, capable of reacting with H-terminated or oxidized silicon surfaces, is described. Analogous to known Wittig reactions, polyenedialdehydes 1 and 3, the latter derived from 1 and phosphonium chloride 2 in a twofold Wittig olefination, were converted with phosphonium bromides 4 to give the (all-E)-arylpolyenaldehydes 5 and 6. A terminal alkyl chain was introduced in dialdehydes 1a and 3a by reaction with P,P-didecyldibenzophospholium bromide 8, resulting in polyenals 9. Wittig olefination of 5c and 9a with phosphonium chloride 2 afforded the (2-thienyl)tridecahexaenal 7 and the docosahexaenal 10. With respect to monolayer formation on oxidized Si(100) surfaces, (9-anthryl)- and (2-thienyl)-ω-functionalized polyenetriethoxysilanes 16 and 17 were prepared in a reaction sequence involving the introduction of a terminal triple bond with [3-(trimethylsilyl)prop-2-ynyl]triphenylphosphonium bromide (11), desilylation of the resulting arylpolyeninetrimethylsilanes 12, 13 with Bu4NF3H2O, and subsequent hydrosilylation of the arylpolyenines 14, 15 using triethoxysilane under dichlorocyclooctadienylplatinum(II) catalysis.

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Arbeitsvorschrift der BASF AG.