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Preparation and Catalytic Evaluation of a Palladium Catalyst Deposited over Two‐Dimensional Zeolite ITQ‐2 Modified with N‐Donor Groups
Author(s) -
Štěpnička Petr,
Křečková Pavlína,
Semler Miloslav,
Čejka Jiří
Publication year - 2014
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201300389
Subject(s) - chemistry , catalysis , ethylamine , palladium , triethoxysilane , yield (engineering) , medicinal chemistry , anhydrous , selectivity , methyl acrylate , zeolite , organic chemistry , polymer chemistry , inorganic chemistry , nuclear chemistry , polymer , materials science , copolymer , metallurgy
Two‐dimensional zeolite ITQ‐2 was reacted successively with (3‐chloropropyl)triethoxysilane, 2‐( N , N ‐diethylamino)ethylamine, and ammonia to give a support bearing the ≡Si(CH 2 ) 3 NHCH 2 CH 2 NEt 2 groups at the surface. Subsequent treatment with palladium(II) acetate afforded an immobilized palladium catalyst 3 , which was tested in the Heck coupling of n ‐butyl acrylate with bromobenzene to give n ‐butyl cinnamate ( 4 ). This (pre)catalyst, which acts as a source of active metal species for the reaction occurring in the liquid phase, showed good activity in N , N ‐dimethylformamide and N , N ‐dimethylacetamide at 150 °C. Reaction tests with different bases revealed a pronounced effect of the base additive on the course of the catalyzed process in terms of both the activity (yield of the coupling product) and selectivity [amount of n ‐butyl 3, 3‐diphenylacrylate ( 5 ) resulting from twofold arylation]. Among the hydrated bases, the best yields of 4 were obtained in reactions performed in the presence of CH 3 CO 2 Na · 3H 2 O and Na 3 PO 4 · 12H 2 O, while that with Na 2 CO 3 · 10H 2 O furnished considerably worse results. The use of the respective anhydrous bases not only decreased the yield of 4 but also incited the formation of the unwanted doubly arylated product 5 .