Olefin transformations

Retrosynthetic addition of elements such as sulfur, selenium, phosphorous or boron may be required as part of a disconnective sequence, as in the Julia-Lythgoe E olefin transform as applied to 33. 

The acidic character of 5A zeolite as a function of the calcium content has been explored by different techniques propylene adsorption experiments, ammonia thermodesorption followed by microgravimetry and FTIR spectroscopy. Propylene is chemisorbed and slowly transformed in carbonaceous compounds (coke) which remain trapped inside the zeolite pores. The coke quantities increase with the Ca2+ content. Olefin transformation results from an oligomerization catalytic process involving acidic adsorption sites. Ammonia thermodesorption studies as well as FTIR experiments have revealed the presence of acidic sites able to protonate NH3 molecules. This site number is also correlated to the Ca2+ ion content. As it has been observed for FAU zeolite exchanged with di- or trivalent metal cations, these sites are probably CaOH+ species whose vas(OH) mode have a spectral signature around 3567 cm"1. 

J.L. Herisson and Y. Chauvin, Catalysis of olefin transformations by tungsten complexes. II telomerization of cyclic olefins in the presence of acyclic olefins, Makromol. Chem., 141 161-176,1971. 

Investigations by Knox and Wells [21, 22], devoted to the determination of alkane oxidation mechanism, led to the conclusion that alkane oxidation mainly proceeded via oxidation of corresponded olefin, transformed at the initial stage and oxidation via peroxide alkyl radicals yielded in only 20% ... 

The chiral organolanthanides have been especially designed for asymmetric catalysis. Thus far several enantioselective olefin transformations (hydrogenation, hydroamination/cyclization, hydrosilylation) as well as the polymerization of methyl methacrylate mediated by these chiral organolanthanide metallocenes have been investigated. 

J.-L. Herisson, and Y. Chauvin, Catalysis of Olefin Transformations by Tungsten Complexes. Telomerization of Cyclic Olefins in the Presence of Acyclic Olefins, Makro-mol. Chem. 141, 161-167 (1971). 

The fundamental carbonium ion-type reactions of olefins— including double bond and carbon skeleton isomerization, polymerization, isotopic exchange, and hydrogen transfer—have been reviewed earlier (62). The importance of a thorough understanding of the nature of olefin transformations over zeolite catalysts cannot be underestimated. Probably the most important and frequently recurring pattern is the transfer or redistribution of hydrogen that is observed with olefins over acidic crystalline aluminosilicate catalysts. 

The following catalytic olefin transformations are another domain of metallocene complexes [140], and hence are closely related to those described in the preceding sections, e. g., with respect to type of catalyst and mechanistic steps. 

Schollkopf, U. Carbonyl-olefin transformation with (C6H6)3P=CH2.-Wittig reaction. Angew. Chem. 1959, 71, 260-273. 

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