Dicyclopentadiene hydrogenation

Hydrogenated Resins Hydrogenated C9 Hydrogenated dicyclopentadiene Hydrogenated terpenes Hydrogenated pure monomer resins... 

Cyclic Polyolefins (GPO) and Gycloolefin Copolymers (GOG). Japanese and European companies are developing amorphous cycHc polyolefins as substrate materials for optical data storage (213—217). The materials are based on dicyclopentadiene and/or tetracyclododecene (10), where R = H, alkyl, or COOCH. Products are formed by Ziegler-Natta polymerization with addition of ethylene or propylene (11) or so-called metathesis polymerization and hydrogenation (12), (101,216). These products may stiU contain about 10% of the dicycHc stmcture (216). 

Dicyclopentadiene (24) [77-73-6] is an inexpensive raw material for hydrocyanation to (25), a mixture of l,5-dicarbonittile [70874-28-1] and 2,5-dicarbonittile [70874-29-2], then subsequent hydrogenation to produce tricyclodecanediamine, TCD diamine (26). This developmental product, a mixture of endo and exo, cis and trans isomers, is offered by Hoechst. 

Dicyclopentadiene can be hydrogenated conveniently over a platinum catalyst in a Parr apparatus. The tetrahydro product is used in the synthesis of adamantane (Chapter 15, Section I). 

Dicyclopentadiene (50 g, 0.38 mole) is dissolved in 100 ml of anhydrous ether. Platinum oxide (0.25 g) is added, and the mixture is hydrogenated in a Parr apparatus at an initial pressure of 50 psi. Initially the reaction mixture becomes warm. The absorption of 2 mole equivalents of hydrogen takes 4-6 hours. The mixture is filtered by suction to remove the catalyst, and the filtrate is distilled at atmospheric pressure through a short fractionating column. 

A recent patent describes the synthesis and catalytic use of Al-containing TUD-1 materials. Some of the reactions demonstrated inclnde hydrogenation of mesitylene (Pt as active metal) and dehydration of 1-phenyl-ethanol to styrene. Several other conceptnal reactions were also described, amongst others the Diels-Alder reaction of crotonaldehyde and dicyclopentadiene and the amination of phenol with ammonia. 

Hydrogenated vegetable oil, in cosmetic molded sticks, 7 840t Hydrogenation(s), 13 769 acetylene, 1 180 10 613-614 alkylanthraquinone, 14 47 asymmetric, 5 210—212 butadiene, 4 370 carbon monoxide, 5 3 carbon dioxide, 26 881 catalytic, 10 504 catalytic aerogels for, l 763t chlorocarbons, 6 235 conditions of, 10 810 cyclopentadiene and dicyclopentadiene, 8 224-225... 

K. Obuchi, M. Tokoro, T. Suzuki, H. Tanisho, and K. Otoi, Thermoplastic dicyclopentadiene-base open-ring polymers, hydrogenated derivatives thereof, and processes for the preparation of both, US Patent 6511 756, assigned to Nippon Zeon Co., Ltd. (Tokyo, JP), January 28, 2003. 

The cyclopent-2-enone required for the photodimerisation is prepared by the hydrolysis and oxidation of 3-chlorocyclopentene, which is obtained by the low temperature addition of hydrogen chloride to cyclopentadiene. The latter is obtained by heating dicyclopentadiene. This depolymerisation is an example of a reverse (or retro) Diels-Alder cycloaddition reaction the diene readily reforms the dicyclopentadiene on standing at room temperature. 

The carbon skeleton of dicyclopentadiene must be the same as that of its hydrogenation product, and dicyclopentadiene must contain two double bonds, since 2 mol of hydrogen are consumed in its hydrogenation (C10H12 ------- C10H16). 

The only practical laboratory preparation of cyclopentadiene is by the depolymerization of dicyclopentadiene.3 4-6 6 3-Chloro-cyclopentene has been prepared by the addition of hydrogen chloride to cyclopentadiene.2 7 8 9 10... 

Silvergerg SE, Lattner JR, Sanchez LE. Use of hydrogenative catalytic distillation to produce cyclopentane and/or cyclopentene from dicyclopentadiene. WO 0029358, Exxon Chemical Patents Inc., 2000. 

Application Increase the value of steam cracker pyrolysis gasoline (py-gas) using conversion, distillation and selective hydrogenation processes. Pygas, the C5-C9 fraction issuing from steam crackers, is a potential source of products such as dicyclopentadiene (DCPD), isoprene, cyclopentane, benzene, toluene and xylenes. 

Reactions were also attempted in the presence of N,NyN, N -tetra-methylethylenediamine. Unlike the dicyclopentadiene examples these reactions gave copious formation of hydrogen sulfide. 

The skeletal isomerization of tetrabydrodicyclopentadiene into adamantane is an example of a very complex rearrangement diat is commercially carried out over strong Lewis acids with a hydride transfer initiator. The reaction can be catalyzed by rare earth (La, Ce, Y, Nd, Yb) exchanged faujasites (Scheme 1) in a Hj/HCl atmosphere at 25(yX3. Selectivities to adamantane of up to 50% have been reported, when a metal fimction, such as Pt, capable of catalyzing hydrogenation is added [54]. Initially acid catalyzed endo- to exo- isomerization of tetrahydro-dicyclopentadiene takes place and then a series of 1,2 alkyl shifts involving secondary and tertiary carbonium ions leads eventually to adamantane[55]. The possible mechanistic pathways of adamantane formation from tetrahydro-dicyclopentadiene are discussed in detail in ref [56]. 

V.M. Gryaznov, M.M. Ermilova, S.I. Zavodchenko, and M.A. Gordeeva, Hydrogenation of dicyclopentadiene (tricyclo[5.2.1.02,6]-deca-3,8-diene) on membrane catalysts from palla-... 

Even though the second double bond provides some stabilization, resistance of the compounds to decomposition by Pd(II)-assisted hydride transfer is interesting. Thus, Pd (II) alkyls with -hydrogens even when they have phosphine groups (which would be expected to be better than olefin groups in stabilizing Pd(II) alkyls) decompose rapidly. As recently discussed by Stille and Morgan (39), the stability of the adducts from bicyclic olefins such as the one from dicyclopentadiene (Reaction 72) can probably be reasonably attributed to the fact that Pd( II)-hydride elimination would form a strained double bond. However, the stability of the adduct from 1,5-cyclooctadiene cannot be explained in this way. 

Since this reaction is a unimolecular example of the selective hydrogenation of an alkene mixture, the successful saturation of the less-substituted double bond should take place most readily over those catalysts that are most effective for the preferential saturation of one olefin in a mixture. Ruthenium has not been used extensively for such hydrogenations, but P-2 Ni(B) has been effective in promoting the selective hydrogenation of one of the double bonds in 46, methylene norbornene (49) (Eqn. 15.30), dicyclopentadiene (50) (Eqn. 15.31), and 2-methyl-1,5-hexadiene (51) (Eqn. 15.32).6 9,80,81... 

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