Hydrogen of isoprene

Iron introduced into PCI/AI2O3 catalyst by controlled surface reaction promoted the activity of the catalyst in the liquid-phase hydrogenation of isoprene. When Fe was introduced by impregnation or coimpregnation, it had an opposite effect55. 

Fig. 18. (A) Hydrogenation of isoprene on Raney nickel without thiophene P, isopen-...

TABLE 3.10 The Products (%) in Half-Hydrogenation of Isoprene over Platinum, Palladium, and Raney Ni"... 

Table IV. Effect of Cyanide Concentration on Products of the Hydrogenation of Isoprene...

The hydrogenation of isoprene, 75, however shows the reverse trend with the primary product from 1,2-addition being 2-methyl-l-butene (Eqn. 15.45), which is formed in about 75% yield over copper chromite catalysts. " The hydrogenation of isoprene over a sulfided Raney nickel catalyst "3 took place primarily by way of a 1,4-addition process to give 2-methyl-2-butene (Eqn. 15.45). 

Scheme 2 Hydrogenation of isoprene over MoS ref. 25). Proportions of product isomers route 1, 0. 77 route 2,0.21...

TABLE 8.12. Hydrogenation of Isoprene (2-Methyl-l,2-Butadiene) Product Selectivities Obtained with Palladium Catalysts, and Matching Calculations ... 

Copolymers.—Both Monomers Vinyl. Ethylene-propylene copolymers have attracted the greatest attention,befitting their industrial importance. A variety of techniques has been used to assign the rather complex C spectra observed, including the synthesis of model oligomers and model polymers e.g. by hydrogenation of isoprene ). Propylene may add by either primary or secondary insertion, and a terpolymerization model has therefore been used to quantify the sequence distribution. Alternatively, Randall has proposed an analysis in terms of —CHa— or —CH(CHs)— units, rather than monomer residues. 

Prop. NMR (1938) and mass (8 8, 85O) spectra, retarding effect on hydrogenation of isoprene with Raney Ni (23I6). 

T.-B. Lin, T.-C. Chou, 1994, Selective hydrogenation of isoprene on eggshell and uniform palladium profile catalysts, Apphed Catalysis A General, 108,7-19. 

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