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ID 34818
file
creator
Lu, Zhou
Mizumo, Tomonobu
subject
Polysiloxane
Boromosilane
Iodosilane
Palladium catalyst
Cyclic ether
Lactone
NDC
Chemistry
abstract
Polysiloxanes are useful materials because of their functionality, such as high thermal stability, electrical resistance, and hydrophobicity. In this regard, we studied palladium-catalyzed formation of iodo-and bromopolysiloxanes from two types of hydrosiloxanes, alpha,omega-dihydropoly(dimethylsiloxane) (1) and cyclotetra(hydromethylsiloxane) (2), and their reactions. Treatment of 1 with mixtures of cyclic ethers or lactones and MeI or allylBr in the presence of a catalytic amount of PdCl2 gave the corresponding alpha,omega-bis(haloalkoxy and haloalkanoyloxy) poly(dimethylsiloxane)s in good yields, via iodo-and bromopoly(dimethylsiloxane) intermediates. Transformation of the iodobutoxy-terminal units in the resulting poly(dimethylsiloxane) into aminoalkoxy groups was examined. The formation of alpha,omega-diiodo- and dibromopoly(dimethylsiloxane)s from 1 was confirmed by spectrometric analysis as well as by quenching experiments with ethanol. A reaction of alpha,omega-dibromopoly(dimethylsiloxane) with 2,5-dilithiothiophene gave a polydimethylsiloxane-thiophene alternating polymer. Similar palladiumcatalyzed reactions of 2 with THF/MeI, THF/allylBr, and delta-valerolactone/allylBr afforded cyclo(halobutoxy- and bromobutanoyloxymethylsiloxane) s in moderate yields. This would provide a new strategy for the introduction of various substituents to the terminal positions of linear polysiloxane and to the cyclosiloxane core.
journal title
Journal of Organometallic Chemistry
volume
Volume 697
issue
Issue 1
start page
51
end page
56
date of issued
2012
publisher
Elsevier Science SA
issn
0022-328X
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
(c) 2012 Elsevier B.V. All rights reserved.
relation url
department
Graduate School of Engineering