Res. Chem. Intermed.
, Vol. 32, No. 9, pp. 887–894 (2006)
Also available online - www.brill.nl/rci
Selective and recyclable palladium porphyrins-catalyzed
oligomerization of tert-butyl acetylene
in environment-friendly ionic liquids
, GUO-FENG WEI
and ZU-LIANG HUANG
School of Basic Medical Science, Youjiang Medical College for Nationalities, Baise 533000, China
Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences,
Guangzhou 510650, China
Received 9 May 2006; accepted 11 August 2006
Abstract—Efﬁcient and selective palladium porphyrins-catalyzed olimerization of tert-butyl acety-
lene to form (3Z,5Z)-2,2,7,7-tetramethyl-3,6-dihalo-3,5-octadiene has been developed in environment-
friendly ionic liquids. The reaction proceeded readily with effective recycling of the ionic liquids and
easy isolation of the products.
Keywords: Palladium porphyrins; ionic liquids; oligomerization; environment friendly.
Conjugated 1,3-dienes are useful as building blocks in organic and pharmaceutical
synthesis and are found in many natural and synthetic products that display a wide
range of biological activities . For these reasons, the development of efﬁcient
and selective methods for the synthesis of conjugated 1,3-dienes remains an area of
current interest [2–10].
We have recently developed a selective approach, using palladium-catalyzed
dimerization transformations of alkynes, to selectively construct a functionalized
1,3-diene, i.e., (3Z,5Z)-2,2,7,7-tetramethyl-3,6-dichloro-3,5-octadiene. Traditional
solvents were found to play an important role in controlling the chemoselectivity
of palladium-chloride-catalyzed oligomerization reactions . In the benzene/n-
BuOH binary solvent system, 1,3,5-tri-tert-butylbenzene, (3Z,5Z)-2,2,7,7-tetramet-
hyl-3,6-dichloro-3,5-octadiene and 2,2,7,7-tetramethyl-3,5-octadiyne were obtain-
ed, respectively, by regulating the solvent. For example, when the reaction was done
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