Cycloisomerisation of 1,6-Dienes in the Presence of Cationic Palladium Catalysts

Synlett ◽  
1998 ◽  
Vol 1998 (11) ◽  
pp. 1211-1212 ◽  
Author(s):  
Andreas Heumann
Keyword(s):  
Palladium Catalysts ◽  
Cationic Palladium

scholarly journals Palladium Catalyzed Alternating Cooligomerization of Ethylene and Carbon Monoxide to Unsaturated Ketones

1995 ◽  
Vol 50 (3) ◽  
pp. 430-438 ◽  
Author(s):  
Wilhelm Keim ◽  
Heiko Maas ◽  
Stefan Mecking
Keyword(s):  
Carbon Monoxide ◽  
Palladium Catalysts ◽  
Methylene Chloride ◽  
General Structure ◽  
Phosphine Ligands ◽  
Unsaturated Ketones ◽  
Palladium Catalyzed ◽  
First Time ◽  
Cationic Palladium

Cationic palladium catalysts have been used to cooligomerize ethylene and carbon monoxide. At high ethylene/CO ratios (m /m = 10:1) in methylene chloride as a solvent, unsaturated alternating cooligomers of the general structure R[C(O)CH2CH2]mH ( m ≥ 1 ; R ≡CH2=CH-, CH2=CHCH2CH2- and CH3CH = CHCH2-) were obtained for the first time. Single component catalyst precursors [(allyl)Pd(P^X )]+Y- (P^X = Ph2P(CH2)nC(= O )OR, Ph2P(CH2)2P(=O)Ph2, Ph2P(CH2)nPh2P(CH2)2S (=O )Ph, n = 1 - 3 , R = Me, Et; Y- = BF4-, SbF6- ) with bidentate P,O- and P,S-ligands as well as in situ catalysts with unfunctionalized phosphine ligands were used. With P"Bu3 as a ligand, selectivities for ethylvinylketone of 40% based on the CO converted were obtained. The hemilabile phosphino-ester and phosphinothiophene ligands behave like monodentate phosphines under catalytic conditions.

Model reactions for the study of hydrogenation and acidic activity of palladium catalysts

1987 ◽  
Vol 52 (8) ◽  
pp. 2019-2027 ◽  
Author(s):  
Libor Červený ◽  
Nguyen Thi Du ◽  
Ivo Paseka
Keyword(s):  
Palladium Catalysts ◽  
Styrene Oxide ◽  
Side Reactions ◽  
Pd Catalysts ◽  
Variable Parameters ◽  
Acid Properties ◽  
Liquid Phase Hydrogenation ◽  
Acid Catalysed Reactions ◽  
Different Content ◽  
Model Reactions

Palladium catalysts have been used to study the hydrogenation of 1-phenyl-2-butene-1-ol which is accompanied by several side reactions considered to be acid-catalysed. Another model reaction studied was dehydration and subsequent hydrogenation or hydrogenolysis of 1-phenyl-1,3-propanediol to 3-phenyl-1-propanol, accompanied by formation of propylbenzene. The dehydration and propylbenzene formation can be again classified as acid-catalysed reactions. Another one is methanolysis of styrene oxide taking place under conditions of liquid phase hydrogenation due to the acid properties of Pd-H systems. Hydrogenation activity of Pd catalysts was tested by hydrogenation of cyclohexene. Sixteen Pd catalysts on different supports and with different content of active component were used, their activity and selectivity was determined and the effect of variable parameters in the synthesis of these catalysts on the activity and selectivity is discussed.

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