Olefins cyclic, catalysis

Metallocene catalysis can also make possible the production of copolymers of propylenes with monomers such as long-chain olefins, cyclic olefins and styrene which is not possible with more conventional Ziegler-Natta catalysts. 

In 1981, it was demonstrated (70) that anions of nitro compounds can be involved in C,C-coupling with allyl acetates at the allylic carbon atom with the use of metal complex catalysis. For many years, this observation did not come to the attention of chemists interested in the synthesis of cyclic nitronates. However, Trost demonstrated (71) that this process can be used in the synthesis of five-membered cyclic nitronates from olefins (18) containing two acyl groups in the different allylic positions (Scheme 3.21). 

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. 

The mechanism involving simple nitrogen-coordinated complexes also accounts for reactivities of certain sterically constrained systems. For instance, 3-(diethyamino)cyclohexene undergoes facile isomerization by the action of the BINAP-Rh catalyst (Scheme 18). The atomic arrangement of the substrate is ideal for the mechanism to involve a three-centered transition state for the C—H oxidative addition to produce the cyclometalated intermediate. The high reactivity of this cyclic substrate does not permit any other mechanisms that start from Rh-allylamine chelate complexes in which both the nitrogen and olefinic bond interact with the metallic center. On the other hand, fro/tt-3-(diethylamino)-4-isopropyl-l-methylcyclohexene is inert to the catalysis, because substantial I strain develops during the transition state of the C—H oxidative addition to Rh. 

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 first example of fully aqueous metal catalysis of olefin isomerization was reported by Grubbs et al. in 1994 [2]. These authors adopted [Ru(H20)6](tos)2 (tos = p-toluenesulfonate) [8] as a catalyst, which is highly active for the ring-opening polymerization of strained cyclic olefin. Both allylic alcohol and allylic ethers undergo isomerization in the presence of [Ru(H20)6](tos)2. 

Cycloaddition reactions are transformations involving the fusion of open-chain substrates to cyclic products. Woodward and Hoffmann have divided all concerted cycloaddition reactions into allowed and forbidden categories defined by a complete set of selection rules (5). We address ourselves here to the catalytic operations required of a transition metal to switch the forbidden transformations to allowed. Our attention, therefore, will be directed exclusively to the forbidden reactions. Forbidden-to-allowed catalysis will be discussed as it applies to the simplest, and perhaps most important cycloaddition, the concerted, suprafacial, 1,2-addition of two olefins. 

This interpretation is supported by extension of this novel catalysis to cyclic olefins (32, 32a). Cyclic olefins undergo smooth ring-opening polymerization to polymers which are, in fact, massive ring polyenes of structure XVIII. 

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